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Gulfstream G450 FMS Procedures

In the G450, what we commonly call the "Flight Management System," or FMS, is really just a subject of a data, communications, navigation, and all sorts of other stuff system.

Whatever you call it, knowing how to work through the functions on the Multi-function Control Display Unit (MCDU) will make your life as a pilot easier.


 

Adjust Estimated Departure Time

Scenario: let's say you are in Shannon Ireland heading west so you will be required to get your oceanic clearance on the ground.

More about this: Oceanic Departure.

Ground control will make the call for you when you first talk to them. They do that and pass on to you that Shanwick has given you a hard oceanic entry time at DOGAL of 0837, time is now 0730Z. Engine start and taxi is at your discretion, but if you fail to make DOGAL plus or minus 2 minutes, you may have issues. When do you start engines and taxi?

Using the techniques shown in Oceanic Departure, you know it will take three minutes to taxi and about five minutes to start engines and complete your before taxi checklist. So what time do you need to takeoff?

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Photo: EINN to KBED example, MCDU flight plan with no ETD entered, from Eddie's aircraft.

The FMS isn't much help, but it does give you ETEs for each point.

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Photo: EINN to KBED example, Waypoint legs with no ETD entered, from Eddie's aircraft.

The Waypoint legs 1/6 page shows you it will take 37 minutes to get to DOGAL. The FMS on the G450 does a good time estimating ETAs after a climb so we'll work with this, 37 minutes.

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Photo: EINN to KBED example, Desired ETD in scratch pad, from Eddie's aircraft.

If we want to make 0837Z at DOGAL, we will have to take off at 0800Z. We enter /0800 into the scratch pad, the leading diagonal is needed to keep the FMS from interpreting 0800 to be a waypoint.

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Photo: EINN to KBED example, MCDU flight plan with 0800Z ETD entered, from Eddie's aircraft.

Pressing LSK 1L enters the ETD into the flight plan, which is displayed next to the runway waypoint.

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Photo: EINN to KBED example, Waypoint legs with 0800Z ETD entered, from Eddie's aircraft.

A look at the Waypoint legs 1/6 page verifies our ETA to DOGAL is 0837Z.

Bank Factor

The bank factor used by the FMS is generally a high altitude constraint, since it is ignored when flying a SID, STAR, or an approach. The default value of 7° creates turn radius issues and the people that built the thing recommend you change the value to 15° as a normal practice. If you've ever wondered why the airplane sometimes makes an initial turn in the wrong direction or completely botches a course intercept, this might be the culprit.

More about: Turn Performance.

Changing It

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Photo: Nav Index, Page 1, from Eddie's Aircraft.

Select the Nav Index by pressing the NAV key.

Select NAV IDENT (LSK 3L).

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Photo: Nav Ident Page, from Eddie's Aircraft.

Select MAINTENANCE (LSK 6L).

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Photo: FMS Maintenance Page 1, from Eddie's Aircraft.

Press NEXT to see Page 2.

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Photo: FMS Maintenance Page 2, from Eddie's Aircraft.

Select SETUP (LSK 6L).

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Photo: FMS Setup Page, from Eddie's Aircraft.

Select FLT CONFIG (LSK 1R).

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Photo: MCDU Flight Config Page 1, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-27-150, ¶8]

  • Set the BANK FACTOR. Enter desired bank factor into the scratch pad and line select 1L. The BANK FACTOR entry is used to set bank limits. The default is 7. Any number from 0 to 15 can be entered.
  • The BANK FACTOR is the highest bank angle to be used by the FMS unless a higher angle is needed to maintain protected airspace. The FMS incorporates a model of the protected airspace that includes the tighter restrictions at low altitudes and approach. The FMS checks each turn against the model and increases the bank angle above the entered BANK FACTOR, if required.
  • The BANK FACTOR can be entered at any time but only on the master MCDU when operating in synchronous mode. If the FMS configuration changes from single, independent, or initiated transfer to synchronous mode, the master bank factor overwrites the slave bank factor value.

This factor is only for FMS course management and has nothing to do with the guidance panel Bank Limit Select Button, which toggles between a 17° and 27° bank angle limit in the HDG SEL mode.

What to Set

[Honeywell FMS DirectTo Issue 1 (September 2009), pg. 3.] FMS Pilot Operating Tip]

Set the ‘Bank Factor’ in all CDUs to 15° (NAV, NEXT, MAINT, NEXT, SETUP, FLIGHT CONFIG) The pilot-selectable bank factor setting permits the crew to establish how aggressively the FMS will turn and therefore, how steep the bank angle will be. It is the highest bank angle to be used by the FMS (in the LNAV mode) unless a higher angle is needed to maintain protected airspace. For low settings (such as 7°), the FMS will anticipate course changes further in advance and make shallower turns. For higher values (up to 15°), the turn is initiated closer to the actual turn point and the bank angle is steeper. For most aircraft, the default factory setting is 7°. Problems arise when a pilot initiates a leg change close to the desired waypoint. When 7° is set, the aircraft will initially roll into a 7° bank which may be too shallow and results in ‘S’ turns to the waypoint. When the pilot resets the value to 15° and a leg change or sequence is made, the aircraft will immediately roll into a 15° bank toward the desired track or waypoint. This results in much more accurate turning and decreases the risk of ‘S’ turns.

Note that the pilot-entered Bank Factor setting is ignored when flying a SID, STAR approach, or when the aircraft is within 30nm (Terminal Area) of the departure/arrival airport. In this case, 20° bank is used instead. The bank factor for holding is fixed at 30°. In addition, the bank factor setting is only used for FMS guidance and does not have anything to do with localizer capture rates.

Check RAIM

Checking RAIM is fairly straight forward. For a primer on RAIM, see: Global Navigation Satellite System (GNSS) & Global Positioning Satellite (GPS) System.

System Description

[G450 Aircraft Operating Manual, §2B-17-30]

  • The GNSSU RAIM function ensures the integrity of the data transmitted by the device. The GNSSU has a continuous integrity level (limit) to the FMS that is used to determine if the GNSSU navigation data can be used for the current phase of flight. The GNSSU RAIM function can also detect satellite failures. It isolates and removes failed satellites when it is tracking a sufficient number of satellites for measurement redundancy.
  • The FMS uses predictive RAIM to determine the integrity levels at specific locations/times to support a non-precision approach and pilot's flight planning activities. The GNSSUs have the following types of RAIM predictions:
    • Destination
    • Alternate waypoint
    • Approach area.
  • The destination and alternate waypoint predictions are made at specific locations or they are the estimated time of arrival (ETA) when the FMS makes the request for flight planning purposes. Satellites can be manually deselected or enabled for destination and alternate waypoint predictions. The approach area RAIM prediction is an output of current RAIM projected 5 min into the future. Approach area RAIM is a continuous output that is performed without any interaction with the FMS.

Check RAIM

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Photo: MCDU NAV Index 1 page, from Eddie's aircraft.

Select the NAV Index page by pressing the NAV key.

Select POS SENSORS (LSK 4L)

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Photo: MCDU Position Sensors page, from Eddie's aircraft.

Select GPS 1 STATUS (LSK 5R)

You could check the status of the other GPS as well.

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Photo: MCDU GPS Status page, from Eddie's aircraft.

Select PRED RAIM (LSK 6R)

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Photo: MCDU RAIM page, from Eddie's aircraft.

You now have the RAIM check for here and now, what about there and then?

Select PILOT SEL (LSK 1R)

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Photo: MCDU Pilot Select RAIM page, from Eddie's aircraft.

Enter the PLACE at LSK 1L and the time at 1R and you will be greeted with the RAIM prediction based on the downloaded GPS almanac.

COM/NAV3 to Data Mode

You will normally operate with COM/NAV 3 in DATA. There is a known anomaly where it could switch itself in VOICE when certain radio keys are pressed rapidly and there are times you want to remove the VHF data capability. See: CPDLC Force SATCOM for more about this. Getting COM/NAV 3 back to data can appear harder than it really is, given the MCDU prompt could be missing.

System Description

[G450 Aircraft Operating Manual, §2B] The main purpose of the COM/NAV3 1/1 page is to act as the DATA radio for the datalink function. Access is made on page 2/2 of the radio tuning page. A double push on the LSK 6L accesses the top level page for COM/NAV3 1/1 . This works even when the radio is in the DATA mode. If the radio is tuned to VOR/ILS frequency, there is no prompt to access the DATA function until a COM frequency is tuned.

If COM/NAV3 is tuned to a VOR or ILS frequency, the entire data section of the COM/NAV3 page will be missing. More on this below.

Switch COM/NAV3 to DATA

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Photo: Radio 1 page, from Eddie's aircraft.

Select RADIO

Select NEXT

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Photo: Radio 2 page (NAV mode), from Eddie's notes.

If COM/NAV3 is not in DATA mode, COM or NAV will appear in green and a frequency will also appear in green. In the example drawing, a NAV frequency is active.

While LSK 6L does not look like mode key, it is. Press LSK 6L twice to bring up the COM/NAV3 display page.

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Photo: COM/NAV3 page (NAV mode), from Eddie's notes.

Because there is a navigation frequency tuned, all of the prompts for DATA are missing. You need to tune a voice frequency to make them reappear. In our example the standby frequency is 118.00 so all we have to do is press LSK 2L. (If the standby frequency was also a navigation frequency we would have to enter a valid voice frequency first.)

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Photo: COM/NAV3 page (NAV mode), from Eddie's notes.

Once a valid com frequency is active the data prompts appear. Select DATA by pressing LSK 2R.

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Photo: COM/NAV3 page (DATA mode), from Eddie's notes.

At this point the page indicates COM/NAV3 is in DATA mode.

CPDLC Constrain SATCOM

Satellite Log On Constrained Mode

[G450 Aircraft Operating Manual, §2B-22-40, ¶2.A.]

  • The SATCOM system is automatically turned on and begins attempting to log on as soon as power is applied during aircraft power up. The SDU supports two types of log-on: Automatic and Constrained Mode.
  • When the AES is in the automatic mode, the log-on GES/satellite/spot beam chosen is based on the GES preference. A GES with a preference level of zero is not considered for automatic log-on. The SDU allows the use of tied GES preferences. The SDU resolves tied preferences by selecting the GESs in descending order of satellite elevation. During GES selection, the set of GESs with the highest preference are initially processed to exclude those GESs associated with satellites not in view.
  • Constrained Log-On — Constrained log-on requires the user to manually select the GES to be used for log-on. The pilot command originates from the MCDU. The GES automatic preferences have no effect in the constrained log-on mode, and it is possible to execute a constrained log-on to a GES with a preference level of zero.
  • If the pilot has manually selected the log-on GES, thus also selecting the satellite, the SDU is constrained to search for the specific GES-related satellite channel used to identify the satellite frequency.

[FMS QTL] In certain situations it may be necessary to constrain a satellite for NAT operations. The recommended procedure is to constrain the satellite that corresponds to the NAT exit area. It has been recommended that when flying eastbound constrain the system to use the Atlantic East satellite. When flying westbound constrain the system to use the Atlantic West satellite.

Some people swear by this technique. We've never used it and have never had a problem. (That's why I had to draw most of these figures.)

G450 Constraining Satellites Procedure

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Photo: MCDU Menu Page, from Eddie's aircraft.

Before ADS-C LOGON on the MCDU press the MENU key.

Press the SAT key (LSK 6L)

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Photo: SATCOM Main Menu page, from Eddie's notes.

Select SUBMENU (LSK 6L)

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Photo: SATCOM submenu, from Eddie's notes.

Select LOG-ON (LSK 2L)

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Photo: SATCOM Logon Menu, from Eddie's notes.

[FMS QTL]

  • For NAT operations the recommended procedure is to constrain the satellite corresponding to the NAT exit area.
  • For GDC:
    • Eastbound constrain the system to use the Atlantic East satellite.
      AUSSAGUEL-AE
    • Westbound constrain the system to use the Atlantic West satellite.
      AUSSAGUEL-AW
  • For ARINC:
    • Eastbound constrain the system to use the Atlantic East satellite.
      EIK-AE
    • Westbound constrain the system to use the Atlantic West satellite.
      STHBURY/EIK-AW

    Select GES SEL (LSK 6L)

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Photo: MCDU GES Selection Page, from Eddie's notes.

Select the satellite you wish to constrain, for the example we will constrain the Atlantic West Satellite so we press LSK 2L

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Photo: SATCOM Logon Menu with SATCOM constrained, from Eddie's aircraft.

The SATCOM Logon page should now report "LOGGED-ON CONSTRAINED" and in our example the satellite switched to AOR-W.

CPDLC Force SATCOM

Rationale

The CMF should automatically choose SATCOM when there are no VHF data stations available but sometimes it needs a kick to the head to realize that. This procedure denies it the VHF Data, providing that swift kick to the head.

Force SATCOM

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Photo: MCDU Radio 2/2 Page, from Eddie's aircraft.

Press the RADIO key and then NEXT to get the RADIO 2 / 2 page.

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Photo: MCDU Menu Page, from Eddie's aircraft.

Press LSK 6L (COMNAV3) to get the COM / NAV 3 page.

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Photo: MCDU Menu Page, from Eddie's aircraft.

Press LSK 2R to switch MODE from DATA to VOICE.

CPDLC Switch CMF

CMF Explained

[G450 Aircraft Operating Manual, §2B-21-30, ¶4.] The pilot can request GDC services by way of datalink through the Honeywell PLANEVIEW communications management function (CMF) datalink platform. This is a two-way data communications system between aircraft and ground systems. A complete datalink communication generated either manually or automatically is referred to as a datalink message. Messages from the aircraft to the ground are referred to as downlink messages and messages from the ground to the aircraft are referred to as uplink messages.

[G450 Aircraft Operating Manual, §2B-21-40, ¶1.]

  • As part of the PLANEVIEW integrated avionics system, the CMF is a next generation datalink platform designed for both software flexibility and hardware expandability. The CMF communicates primarily through a very high frequency (VHF) transceiver, although airborne equipment may, as an option, include a Satellite Data Communication System (SDCS) to provide datalink capability by way of ultra high frequency (UHF) transmissions.
  • By default, the PLANEVIEW CMF communicates by way of the land-based ACARS VHF network, which includes the Aeronautical Radio, Inc. (ARINC) and SITA subnetworks. Based on position information provided by the aircraft FMSs, the CMF automatically tunes to the appropriate subnetwork. In areas where VHF coverage is unavailable, the CMF may use the Inmarsat Aero-H, Aero-H+, or Aero-I satellite UHF networks. This provides both packet mode (datalink) and circuit mode (voice and data) capabilities to the aircraft. The CMF switches to and from the satellite UHF network based on the availability of land-based VHF network coverage.

[G450 Aircraft Operating Manual, §2B-21-60]

  • The CMF features a manual switching capability that permits the flight crew to select either CMF1 or CMF2 as the active CMF. This is provided primarily as a means to force a nonresponsive CMF to relinquish control to the other CMF.
  • When a manual switch is attempted and the standby CMF is functional, the active CMF becomes the standby CMF and the standby CMF becomes the active CMF. The CMF operation is not synchronized between CMF1 and CMF2 so any logged data or new messages are lost upon switching. Pilot-entered selections return to default settings when the standby CMF becomes active.
  • If a manual switch is attempted and the standby CMF is unable to become active, the active CMF is set to standby for approximately three seconds and then resumes control. During the course of switching to standby and back to active, the active CMF is reset. The reset of the active CMF results in all logged data and new messages to be lost.
  • If a manual switch is attempted due to a lock-up of the active CMF and the standby CMF is unable to become active, an attempt to reset the active CMF is made in order to clear the lock-up condition. Resolution of the lock-up condition is dependent on the cause of the lock-up.

The CMF is a mix of hardware and software and every now and then, as the operating manual says, it locks up. The following procedure is the fix.

Switching CMF's

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Photo: MCDU Menu Page, from Eddie's aircraft.

Step 1: Select MENU key.

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Photo: MCDU Menu Misc Page, from Eddie's aircraft.

Step 2: Select MISC key, LSK 1L.

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Photo: MCDU Menu CMF2 Page, from Eddie's aircraft.

Step 3: Toggle LSK 5L to select the other CMF.  It will take a few seconds but you should see the change reflected on the screen.

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Photo: ATC Log On Status Page, from Eddie's aircraft.

Once this is done, check the ATC LOGON STATUS page, NAV > ATC (LSK 1R)

CPDLC Unconstrain SATCOM

Satellite Log On Constrained Mode

[G450 Aircraft Operating Manual, §2B-22-40, ¶2.A.]

  • The SATCOM system is automatically turned on and begins attempting to log on as soon as power is applied during aircraft power up. The SDU supports two types of log-on: Automatic and Constrained Mode.
  • When the AES is in the automatic mode, the log-on GES/satellite/spot beam chosen is based on the GES preference. A GES with a preference level of zero is not considered for automatic log-on. The SDU allows the use of tied GES preferences. The SDU resolves tied preferences by selecting the GESs in descending order of satellite elevation. During GES selection, the set of GESs with the highest preference are initially processed to exclude those GESs associated with satellites not in view.
  • Constrained Log-On — Constrained log-on requires the user to manually select the GES to be used for log-on. The pilot command originates from the MCDU. The GES automatic preferences have no effect in the constrained log-on mode, and it is possible to execute a constrained log-on to a GES with a preference level of zero.
  • If the pilot has manually selected the log-on GES, thus also selecting the satellite, the SDU is constrained to search for the specific GES-related satellite channel used to identify the satellite frequency.

G450 Unconstraining Satellites Procedure

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Photo: MCDU Menu Page, from Eddie's aircraft.

Press the SAT key (LSK 6L)

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Photo: SATCOM Main Menu page, from Eddie's notes.

Select SUBMENU (LSK 6L)

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Photo: SATCOM submenu constrained, from Eddie's notes.

Select LOG-ON (LSK 2L)

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Photo: SATCOM Logon Menu with SATCOM constrained, from Eddie's aircraft.

Select AUTO LOG-ON (LSK 2L)

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Photo: SATCOM Logon Menu, from Eddie's notes.

You should now be back to unconstrained.

CPDLC Weather Diversion

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Photo: MCDU ATC Index page, from Eddie's aircraft.

When you need to make an adjustment due to weather, the CPDLC procedure begins with the ATC Index page. LSK 2L gets you to the ATC REQUEST page.

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Photo: MCDU ATC Request page, from Eddie's aircraft.

This page gives you the option of requesting a change in altitude (LSK 1L) or speed (LSK 2L), a offset from course (LSK 1R), or a reroute (LSK 2R). The first three options give you an opportunity to add "DUE TO WEATHER" and the final option allows you to enter that as free text. We'll look at the offset for an example by pressing LSK 1R.

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Photo: MCDU ATC Offset Request page, from Eddie's aircraft.

From there you enter the direction and number of nautical miles, "R25" as an example. If you want to add "DUE TO WEATHER" by pressing LSK 2R.

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Photo: MCDU ATC Offset Request page, from Eddie's aircraft.

Then press LSK 6R to send the message. (The "OFFSET AT" is optional.)

Create Stored Flight Plan

Create Stored Flight Plan Procedure

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Photo: MCDU Nav Index Page 1, from Eddie's aircraft.

Select the Nav Index by pressing the NAV key.

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Photo: MCDU Flight Plan List Page Example, from Eddie's aircraft.

You will see a list of previously created flight plans along with a blank entry at LSK 1L.

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Photo: MCDU Flight Plan List Page With Scratch Pad Entry Example, from Eddie's aircraft.

Enter an airport pair in ICAO format separated by a dash, LSGG-KBED in the example. Press LSK 1L.

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Photo: MCDU Flight Plan Select Activate Example, from Eddie's aircraft.

The MCDU allows you to activate (LSK 1R), Invert and Activate (LSK 2R), or enter performance for the stored flight plan (LSK 3R). For the sake of this example, we will activate (LSK 1R).

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Photo: MCDU Flight Plan LSGG-KBED Example, from Eddie's aircraft.

The flight plan is now ready for further entries.

Rules for Stored Flight Plan Initialization

Rather than activate the stored flight plan you can go directly to its performance pages. The rules for this is similar to doing a "what if" exercise.

G450 Aircraft Operating Manual, §2B-26-110, ¶1.]

  • The initialization rules are the same as for the WHAT-IF initialization with the following exceptions:
    • The cruise altitude defaults to OPTIMUM, regardless of the active performance initialization. This is because the active cruise altitude may not be the best for a stored flight plan. For example, the stored flight plan may be a short leg that requires a low cruise altitude while the current flight can be flown at a high altitude and vice versa.
    • The takeoff fuel allowance is set to the general default. While in flight, the active and the WHAT-IF initialization both have zero fuel for the takeoff allowance.
    • The fuel must always be entered. This is required for computing a gross weight. Since fuel is not known at this time, a rough estimate is sufficient. When the fuel required is computed, that fuel weight can be reentered to refine the estimate, if significantly different from the entered fuel.
    • Once the stored flight plan data has been computed, all initialization parameters are displayed in large characters. At that point the stored flight plan initialization no longer tracks changes made to the active initialization.
  • When all required entries are made, the CONFIRM INIT prompt is displayed at 4R. The CONFIRM INIT prompt must be pushed to start the calculation.

Departure Coding

Navigation procedures are coded in the FMS according to the ARINC 424 specification. It isn't important to know that, other than to know there is something going on above and beyond the avionics and aircraft manufacturer. Understanding it, however, can help when trying to figure our "what's it doing now?"

Procedure Design

[Honeywell Direct-To]

  • The FMS is designed to process flight plan waypoints as they are defined by ARINC 424 (Navigation System Database Specification). This has led to a very reliable navigation system over a period of many years. So while airport terminal procedures grow in complexity over time, the FMS needs to accommodate change while utilizing existing software coding and specifications.
  • When procedures are designed, typically using PANS-OPS or TERPS, the lateral and vertical paths are defined in a manner that will provide obstacle protection. Once the procedure has been designed and approved it can then be encoded. The navigation database in any Honeywell FMS is developed using data that is supplied by a vendor. The vendor is called a Type I Data Supplier, and the two largest in the industry are currently Jeppesen and Lido. These suppliers will collect navigation data from various official state sources around the world. The data is then encoded using ARINC 424 and distributed to various users such as FMS manufacturers. The FMS manufacturers are considered a Type II data supplier, as the encoded data received must be translated into a language that can be read by the FMS. This process follows stringent requirements to ensure accuracy. Honeywell's navigation database production process has been deemed compliant with RTCA/DO-200A and FAA advisory circular AC20-153, and offers very high data integrity.
  • The waypoints loaded into a terminal procedure are linked together using ARINC 424 Path and Terminator, often referred to as leg types. The two elements of the Path and Terminator prescribe the way in which a path is to be flown and how the path is to be terminated.
  • There are several path terminators that are consistently used in procedure design. This review will cover four of the 23 different path terminators by walking through an example departure procedure. This will include the following path terminators:
    • VA – Vector or heading to an Altitude
    • CA – Course to an Altitude
    • DF – Direct to a Fix
    • TF – Track to a Fix
  • Figure 1 shows the plan view of the West Palm Beach (KPBI) IVNKA1 Departure procedure. As seen in the figure, there are four runway transitions that could be loaded into the FMS. In this example, we will first review the runway 14 transition.
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    Figure 1

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    Figure 2

  • Looking at the plan view (figure 1) and the textual description (figure 2) of the procedure departing from runway 14, the aircraft is to fly a heading of 141 degrees until reaching 520 feet. The procedure designer wants the aircraft to reach the specified altitude prior to making any turns. This introduces the first two Path Terminators, the VA or Vector to an Altitude (figure 3) and CA or Course to an Altitude (Figure 4). In the CA, note the addition of a red waypoint symbol. This is because the VA uses a simple Vector or Heading flown, and the CA uses a defined Course. To fly a course there must be a starting point that defines exactly where the course will be flown. There are certain FMS types that are not able to process a VA, so it will be converted to a CA by the navigation database compiling tool.
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    Figure 3

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    Figure 4

  • When the procedure is loaded into the NZ-2000 FMS (figure 5), it displays the waypoint *ALT01 with a course of 141 degrees and the vertical constraint of 0520A. The waypoint name, *ALT01, informs the pilot that waypoint sequencing will occur once the altitude constraint has been met. Note also, the calculated course to UFIRD is 085 degrees.
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    Figure 5

  • Returning to Figure 1 and 2, after *ALT01 the procedure designer wants the aircraft to proceed directly to UFIRD. Because the previous Path Terminator did not have a specified geographic location where it would terminate, due to variable aircraft climb performance, the navigation data must now command a new calculation to steer the aircraft to the desired waypoint.
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    Figure 6

  • As mentioned before, the calculated course into UFIRD while on the ground awaiting takeoff was 085 degrees (figure 5). After sequencing the altitude waypoint, the new course calculated to UFIRD is 074 degrees. This is because the actual distance to reach the altitude was farther than the calculated distance. In other words, it essentially took the aircraft longer to reach the altitude than predicted. In the example, after take off and sequencing the altitude waypoint, if the next (TO) waypoint is encoded with a DF as the path terminator (Figure 6), the FMS will calculate a path from the current position of the aircraft directly to that waypoint. Keep in mind that intercept algorithms provide a smooth turn to the waypoint and help reduce the S-turning to rejoin a path that could now be behind the aircraft.
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    Figure 7

  • The Track to a Fix or TF path terminator (Figure 8) simply tells the FMS to connect one fix to the next by using a great circle route. It is the simplest of path terminators and is very commonly used to link waypoints together. Procedure designers can position waypoints using latitude/longitude and use TF path terminators thus allowing the FMS to connect them.
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    Figure 8

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    Figure 9

  • Looking at the database coding in Figure 9, the path terminators are listed in the PT column, the course and heading under Cs/Hd, and the altitude is listed under Alt1.

Download Flight Plan

The download flight plan procedure is easy enough, except when the downlink is not available. You will need line of sight with either a VHF ground station or an INMARSAT satellite. Patience is usually enough to achieve this. Where does the flight plan originate? The usual suspects are GDC and Arinc-Direct but you can use other vendors too. Just make sure they send the flight plan to GDC with a recall number that is GDC/Arinc compatible.

Data Link Service Provider Line of Sight Limitation

[G450 Aircraft Operating Manual, §2B-21-40, ¶1.]

  • By default, the PLANEVIEW CMF communicates by way of the land-based ACARS VHF network, which includes the Aeronautical Radio, Inc. (ARINC) and SITA subnetworks. Based on position information provided by the aircraft FMSs, the CMF automatically tunes to the appropriate subnetwork. In areas where VHF coverage is unavailable, the CMF may use the Inmarsat Aero-H, Aero-H+, or Aero-I satellite UHF networks. This provides both packet mode (datalink) and circuit mode (voice and data) capabilities to the aircraft. The CMF switches to and from the satellite UHF network based on the availability of land-based VHF network coverage.
  • As a provider of flight support services, the GDC is at the hub of the system. In addition to performing host processing for CMF datalink message traffic, the GDC has telephone, fax, and network connections to domestic and international ATC facilities, fixed-base operators (FBO), multiple weather providers, and customer flight departments.
  • All PLANEVIEW CMF transmissions, whether VHF or satellite, require line of sight to a VHF ground station or Inmarsat satellite, respectively. Refer to the map of GDC datalink coverage, shown at the end of this section.
  • Establishing and maintaining line of sight is most often a concern when transmitting VHF on the ground due to the curvature of the Earth, high surrounding terrain, and man made structures. VHF transmissions from many airports are simply not possible because the nearest VHF ground station is below the horizon or blocked by surrounding terrain. Even at airports with on-airport VHF ground stations, VHF transmissions from certain areas of the airport may not be successful due to man made structures obstructing line of sight. In flight, VHF coverage is normally excellent, although coverage limitations may exist in remote areas of the world or at low altitudes.
  • Transmitting by way of satellite while on the ground is generally reliable. Although, line of sight issues may still arise due to surrounding terrain and man made structures because the Inmarsat satellites are in an equatorial geostationary orbit. In flight, the curvature of the Earth is a concern only at latitudes greater than 70° North or South. Except at these high latitudes, satellite coverage while in flight is seamless.

You may notice there are certain airports and locations at certain airports that are slower to allow a downlink than others. It may very well be that ground obstructions and normal satellite orbits will routinely give you slower downlinks. You may just have to plan on more time at these locations. We've never failed to get a connection and it has never taken more than five minutes.

G450 Procedure: Download Flight Plan

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Photo: MCDU AOC Main Menu Page, from Eddie's aircraft.

Select the AOC Main Menu by pressing DLK.

Everything on this page comes from your data service provider (GDC or ARINC).

Select FPL/WINDS (LSK 6L)

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Photo: MCDU DATALINK INDEX Page 1, from Eddie's aircraft.

Select FLT PLAN (LSK 1L).

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Photo: MCDU DATA LINK FLT PLAN Request Page, by Flight Plan Number, from Eddie's aircraft.

Enter the flight plan number in the scratch pad and press LSK 2L. Alternatively, you can press LSK 1R and enter the to and from ICAO identifiers and ETD.

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Photo: MCDU DATA LINK FLT PLAN Request Page, Flight Plan Number Entered, from Eddie's aircraft.

Select SEND REQUEST (LSK 6R)

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Photo: MCDU FLT PLAN RECEIVED prompt, from Eddie's aircraft.

Once the FLT PLAN RECEIVED prompt is received, return to this page and select FPL REVIEW (LSK 5R)

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Photo: MCDU DATALINK FPL REVIEW Page Example, from Eddie's aircraft.

You can review the entire flight plan using the NEXT and PREV key and complete the download by selecting ACTIVATE (LSK 6R)

Holding Pattern

Holding Pattern Description

[G450 Aircraft Operating Manual, §2B-27-130, ¶3.]

  • The HOLDING PATTERN page is used to define and review holding patterns. Holding quadrant, inbound course, turn direction, and leg length or time of the inbound leg of a holding pattern can be defined on the HOLDING PATTERN page.
  • he default holding is a standard holding pattern at the designated holding fix with the inbound course set to the flight plan course into the holding fix. Leg times are defaulted to 1 min below 14,000 ft and 1.5 mins at or above 14,000 ft.

G450 Procedure: Holding Pattern Definition and Review

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Photo: Example Flight Plan, from Eddie's aircraft.

Press the DIR key.

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Photo: Example Flight Plan With DIRECT Prompt, from Eddie's aircraft.

DIRECT will appear on the top, press PATTERN (LSK 6L).

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Photo: PATTERNS page, from Eddie's aircraft.

Press HOLD (LSK 1L).

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Photo: Example Flight Plan With HOLD, from Eddie's aircraft.

"*HOLD*" appears in the scratch pad, enter this on the desired holding point using a left LSK. In our example we are holding at DPK so we press LSK 4L.

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Photo: Select Hold Page Example, from Eddie's aircraft.

Select the desired direction of turn: LSK 1L for right and LSK 2L for left.

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Photo: Holding Pattern Definition Page, from Eddie's aircraft.

You can adjust any of the parameters in green and select ACTIVATE (LSK 6R).

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Photo: Example Flight Plan with DPK Hold, from Eddie's aircraft.

The holding pattern is denoted by an "H" and you will see the result on the navigation display as shown on the top of this page.

Initialize Position

There isn't much to this if your normal ramp position gives you a good shot of the GPS satellite constellation. If your GPS usually takes a while to come up, you can speed things up by defining a pilot waypoint RAMPX, where the X can be any letter from A to Z or number from 0 to 9. The FMS will offer that point to you as a choice if you start the airplane up within 3 NM of that position. Normally, however, once the GPS figures out where it is you are better off selecting it.

Inertial Reference Position Initialization

[G450 Aircraft Operating Manual, §2B-14-20]

  • The IR component requires system initialization (entry of latitude and longitude). Initialization can be done using either the flight management system (FMS) input that is manually entered by the crew through the multipurpose control display unit (MCDU) or automatically from the global positioning system (GPS). A pilot-entered position has priority over a position from a GPS.
  • To initialize the FMS position, select the POS INIT line select switch prompt from either the NAV IDENT or POS SENSORS page.

G450 Procedure: Initialize Position

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Photo: MCDU Nav Ident Page, from Eddie's aircraft.

When you first bring power to the aircraft using the emergency batteries, MCDU 1 should display engine instruments and MCDU 3 should show the emergency radio page. MCDU 2? It's got nothing.

After you bring the rest of the electrical system up, MCDU 2 comes up with the screen shown above. You can bring the other two MCDU's to the same screen by selecting NAV > NAV IDENT.

[G450 FMS QTL, Nav Ident

  1. Check/Correct the Date.
  2. Check/Correct the GMT.
  3. The time and date come from the GPS but can be corrected if the GPS doesn't come up.

  4. Verify SW
  5. The software identifier has been NZ7.1 for a while.

  6. Verify Active NDB.
  7. Unlike previous Gulfstreams, the alternate data base will come up automatically if the active data base is expired and the alternate is current.

    More about this: G450 Data Base Update.

Turn the IRS's ON.

Select POS INIT (LSK 6R)

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Photo: MCDU Position Init Page, No Present Position, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-27-160

  • 1L and 1R - The last FMS position is displayed when the aircraft is on the ground. If the line select key adjacent to the LOAD prompt (1R) is pushed, the FMS is initialized to that position.
  • 2L and 2R - The reference waypoint (REF WPT) line is below the last FMS position. This line can be filled automatically by the FMS or the pilot can make an entry at any time. In order of priority, the FMS fills in this line as follows:
    • RUNWAY THRESHOLD - If a departure runway has been selected in the active flight plan, the coordinates of the runway threshold are displayed. Using this feature, runway position can be updated when the aircraft is at the end of the runway ready for takeoff.
    • RAMPX WAYPOINT - If there is a last position available, the FMS compares the last position to the list of RAMPX waypoints. RAMPX waypoints are pilot-defined waypoints with the name of the RAMP plus any alphanumeric (0 through 9, A through Z) character. If one (or more) is found within 3 NM of the last position, the closest one is displayed. If more than one RAMPX waypoint is defined for the same airport, the FMS selects the closest one to the last position. If multiple RAMPX waypoints are defined with the same latitude/longitude, the FMS selects the one with highest alphanumeric priority.
    • AIRPORT REFERENCE POINT (ARP) - If there is a last position available and no RAMPX waypoints are found within 3 NM, the FMS displays the closest ARP within 3 NM.
    • PROMPTS - If none of the above waypoints are displayed, the FMS displays prompts.
  • 3L and 3R - The position of the highest priority GPS is displayed. The priority order, from highest to lowest, is as follows: GPS 1, GPS 2, GPS 3. This order of priority applies to all FMSs. If the line select key adjacent to the LOAD prompt (3R) is pushed, the FMS is initialized to the GPS position.
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Photo: MCDU Position Init Page, Loaded, from Eddie's aircraft.

[G450 FMS QTL, Position Initialization]

  • The selected position becomes the FMS position.
  • "(LOADED)" is displayed above the coordinates selected.
  • If not in SYNCHRONOUS mode Each FMS position must be initialized.

[G450 Aircraft Operating Manual, §03-03-10] Initializing the position on any MCDU / FMS results in initializing the position for all FMSs.

Lateral Offset

Sometimes you need a Strategic Lateral Offset Procedure (SLOP); fortunately you have an easy way to do that in the G450. Can you SLOP with ADS-C? The ICAO says you should, but only in the North Atlantic is it actually in writing that you can.

See: Strategic Lateral Offset Procedure.

Entering / Exiting an Offset from the MCDU

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Photo: MCDU Progress 3/3 Page, from Eddie's aircraft.

Enter Lateral Offset

[G450 Aircraft Operating Manual, §2B-29-20, Procedure 1]

  1. Select PROGRESS page 3
  2. Enter lateral offset into the scratch pad. Enter direction (L or R) and distance in nautical miles.
  3. The decimal is optional. Examples: L1, R1.5, L10, etc.

  4. Enter the offset by pushing line select 1R.

[G450 Aircraft Operating Manual, §2B-31-20, Table 1]

  • The minimum entry is L or R plus one digit
  • Range is 0.1 to 30.0 NM in 0.1 increments

[G450 Aircraft Operating Manual, §2B-29-20, Procedure 1] To manually cancel the lateral offset waypoint, push the DEL key and line select *DELETE* to 1R.

Entering / Exiting an Offset from the Map Display

[G450 Aircraft Operating Manual, §2B-07-20, ¶3.M.]

  • When the cursor is positioned over the aircraft symbol, the aircraft symbol is highlighted by a blue circle. In this situation, the immediate action task menu is displayed by pushing the ENTER switch on the CCD. The task menu contains the following menu items:
    • PPOS Hold
    • Offset, Exit Hold (if holding) or
    • Resume Hold (if exiting hold) or
    • Cancel Offset (if offset active).
  • Selecting Offset from the immediate action menu displays the Offset dialog box. The Offset dialog box is an interface to define/activate lateral offsets on the active FMS leg. The box contains an Offset title positioned in the upper left corner. Two data boxes are displayed on either side of the dialog box labeled Left and Right above them and NM to the right. These data boxes are initially dashed-out. A vertical line is displayed in the middle with a waypoint symbol at the top. A small aircraft symbol is displayed and positioned initially above the data boxes on the vertical line. When the cursor is positioned in the proximity of either the left or right data box/label, a small curly cue is displayed inside the data box and a blue box is drawn around the box/label.
  • When the MFK is rotated, the data displayed in the box increases or decreases in the range of 0.1 to 30.0 NM in 0.1 NM steps and the aircraft symbol moves laterally in the direction of the change.
  • The Delete/Apply buttons are displayed in the lower left/right portions of the box respectively, as shown in Figure 40. When Apply is selected, the FMS activates the prescribed offset immediately and the box is removed. If an offset exists for the active leg when Offset is selected, the Delete box remains available and when selected, cancels the offset. If the cursor is moved off the dialog box, the box closes after the time-out period and no action is taken.
  • The Cancel Offset menu item is displayed in the Immediate Action menu if an offset exists. When selected, the Cancel Offset item cancels the offset. Subsequent to defining a Vectors To Final transition, when the FMS transitions to terminal mode, the Activate Vectors task menu item is available in the immediate action menu. When selecting the Activate Vectors task menu item, the FMS activates the Vectors To Final. The Activate Vectors task menu item is available in the Aircraft Task menu if no transition is in the approach procedure and the FMS transitions to terminal mode.

Offset Indication

[G450 Aircraft Operating Manual, §2B-25-10, ¶9.] OFFSET is an advisory (white) annunciator. The annunciator is displayed when a lateral offset has been entered on the PROGRESS 3 page or graphically. The annunciator is removed or turned off when the offset is removed.

Offsets Prohibited

[G450 Aircraft Operating Manual, §2B-29-20, Procedure 1] Lateral offsets cannot be entered while flying any of the following:

  1. SIDs, STARs, approaches
  2. Patterns
  3. In the terminal area (10 NM from origin, 25 NM from destination)
  4. In the polar region.

Offsets Automatically Cancelled

[G450 Aircraft Operating Manual, §2B-29-20, Procedure 1]

  • Offsets are automatically canceled for the following:
    1. Course changes greater than 90°
    2. SIDs, STARs, approaches
    3. Patterns
    4. Intercepts
  • An OFFSET CANCEL NEXT WPT message is displayed before offset is automatically canceled.

ADS-C Notes

[Gulfstream Operating Manual Supplement OMS-3, ¶5.] The following is a clarification of FMS operation when flying an offset path:

  • For ADS reporting of present position at a waypoint sequence, the FMS position will correctly report the offset position
  • For operation using the NAT Strategic Lateral Offset Procedures (SLOP), the entry of a right one or two NM offset will have negligible effect on the FMS predictions at the next and next + 1 waypoint
  • For a larger than 2 NM offset, e.g. for a weather deviation, the FMS predictions assume that the aircraft will return to the original flight plan prior to the next waypoint. If this is not the case, the crew should advise ATC that the FMS predictions are to the original path and not the offset path.

ADS-C complicates things a bit, since it continuously reports the aircraft's actual position, with or without SLOP. You are clearly allowed to SLOP with ADS-C in the North Atlantic. Elsewhere? The ICAO clearly supports the SLOP concept and the list of countries allowing the practice is growing. But you cannot assume everyplace in the world is okay with it.

See: Strategic Lateral Offset Procedure.

CPDLC Notes

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Photo: MCDU Nav Index, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-33-70, ¶4.] If the aircraft is flying an offset path and the downlink message contains any of the following message elements: ASSIGNED ROUTE, NEXT WAYPOINT, ENSUING WAYPOINT or POSITION REPORT, the downlink message also includes the following message: DEVIATING [distance offset] and [direction] OF ROUTE (e.g., DEVIATING 3NM NORTH OF V58)

You can access the G450 CPDLC system by pressing the NAV key and then selecting ATC (LSK 1R)

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Photo: MCDU ATC Index, from Eddie's aircraft.

Select ATC Request (LSK 2L)

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Photo: MCDU ATC Request, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-33-140] The ATC REQUEST page gives access to more detailed request pages. Entry of a value to a request altitude, speed or offset results in the display of the detailed altitude, speed or offset request pages.

  • Lateral offset requests are displayed in Line 1R. When a message element containing a request for a lateral offset is included in the downlink message, the offset value associated with the message is displayed in line 1R.
  • Valid entries in line 1R are the letters L or R followed by a numerical distance (1 to 30). Valid entries result in the display of the ATC OFFSET REQUEST page with the entered offset value. Entry of a valid offset over an existing offset results in the deselection of the previous message element and any associated requests. Deletion of an entered offset value results in the deselection of any message element containing a request for a lateral offset and any associated offset elements.
  • Dashes are displayed in line 1R when a lateral offset request has not been selected.

[G450 Aircraft Operating Manual, §2B-33-160]

  • Line 1L
    • Line 1L displays the offset entered on either the ATC REQUEST page or on the ATC OFFSET REQUEST page. An entry to line 1L results in the message element REQUEST OFFSET [direction][distance offset] being included in the downlink message.
    • Valid entries to line 1L are the letters L or R followed by a numerical distance (1 to 30). Entry of a offset value results in any previously entered offset value being deleted and any previously selected offset request message element and associated offset request message elements being deleted.
    • Deletion of an offset value results in any previously entered offset value being deleted and any previously selected offset request message element and associated offset request message elements being deleted.
    • Dashes are displayed in line 1L when an offset entry is not valid.
  • Line 1R
    • Line 1R displays the time or position corresponding to an offset request when an offset is displayed in line 1L. A position (waypoint) entry to line 1R includes the message element AT [position] REQUEST OFFSET [direction] [direction offset] in the downlink message. A time entry to line 1R includes the message element AT [time] REQUEST OFFSET [direction] [distance offset] in the downlink message.
    • An entry to line 1R must be in the format of time (HHMM) or position (waypoint). An entry to line 1R is rejected if the entry is not recognized as either a valid time or position.
  • Selection of the DUE TO WEATHER prompt results in two possible message elements being included in the downlink message.
    • AT [position] REQUEST OFFSET [direction] [distance offset] DUE TO WEATHER
    • AT [time] REQUEST OFFSET [direction] [distance offset] DUE TO WEATHER

ATC Request

[G450 Aircraft Operating Manual, §2B-33-70, ¶8.]

Uplink Message Element Corresponding Downlink Message Element
WHEN CAN YOU ACCEPT [direction][distance offset] OFFSET WE CAN ACCEPT OFFSET [direction] [distance offset] AT [time or fix name]
or
WE CANNOT ACCEPT OFFSET [direction] [distance offset]

Emergency Report

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Photo: MCDU Emergency Report Page, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-33-90] The EMERGENCY REPORT page gives the crew with the ability to create and send an emergency report.

  • An entry into the OFFSET field results in the message OFFSETTING OF ROUTE being included in the downlink message.
  • Valid entries in the OFFSET field are a direction and distance with no spaces in between. The direction is L (left) or R (right). The distance is 1 to 30 (NM).
  • Dashes are displayed in the OFFSET field when an entry is not valid.
  • When DELETE is entered into the OFFSET field, while a valid OFFSET entry exists, the message OFFSETING OF ROUTE is deleted from the downlink message, and the OFFSET field returns to dashes.

This page sends the emergency report with indication of the offset, but does not input the offset into the active flight plan.

High Latitude Operations

[G450 Aircraft Operating Manual, §2B-27-150, ¶5.] During operations in the polar region, FMS lateral offset is inhibited. Any entered lateral offset is removed when entering the polar region.

The FMS will more than likely be navigating in True heading mode.

See: High Latitude Operations.

Oceanic Clearance (from data service provider)

This is how we down linked our oceanic clearances before we knew anything about CPDLC, it is basically coming from the "Data Link Service Provider," which means somebody one position removed from ATC. As of January 2014, this is how you downlink your oceanic from everyone except New York Center. For that, see: CPDCL - Downlink Oceanic Clearance from NY Oceanic (via CPDLC).

Eastbound North Atlantic Notes

[FMS QTL]

  • Gander ACC sends the clearance to the GDC 10 to 60 min prior to aircraft entry into oceanic airspace. Gander ACC generally sends the clearance by 70° West longitude.
  • For aircraft departing Gander (CYQX), Goose Bay (CYYR), and St. John's (CYYT) airports, Gander ACC sends the oceanic clearance to the GDC at the same time it sends the departure clearance to the tower. Read back of the oceanic clearance is given to the tower, after which the tower issues the departure clearance.
  • With automatic position reports enabled, the GDC automatically sends the clearance to the aircraft as a datalink message as soon as it is received from Gander ACC.
  • If automatic position reports are disabled, the flight crew must request the clearance. Begin requesting the clearance approaching 70° West longitude, but if the clearance is not received by 25 min prior to entry into oceanic airspace, contact Gander ACC on the appropriate voice frequency.
  • If the GDC has received the oceanic clearance from Gander ACC, the clearance is sent to the aircraft as a datalink message. If the GDC has not received the oceanic clearance from Gander ACC, a datalink message indicating that the oceanic clearance has not been received from Gander ACC and that the oceanic clearance can be requested again in 10 min is sent to the aircraft.
  • Multiple oceanic clearance requests can be sent until 25 min prior to entry into oceanic airspace. Oceanic clearances are valid for 30 min beyond the issue time and voice read back of oceanic clearances is required.

Westbound North Atlantic Notes

[FMS QTL]

  • Delivery of oceanic clearances by way of datalink for westbound transatlantic flights for the Shanwick Oceanic Control Area (OCA) is known as Oceanic Route Clearance Authorization (ORCA) and requires that the aircraft be registered with the GDC for the service.
  • ORCA does not support use of variable call signs. The flight crew should request the clearance by way of datalink between 30 and 90 min prior to entry into the Shanwick OCA. Shanwick normally responds to the clearance request with a message indicating that the clearance should be received within the next 15 min. Shanwick then sends the clearance to the aircraft, which contains:
    • The aircraft registration
    • Entry point, ETA at the entry point
    • Mach number
    • Flight level
    • Route
    • Destination.
  • The flight crew must promptly acknowledge the clearance by way of datalink, by line selecting ACKNOWLEDGE on the message page containing the clearance. Failure to promptly acknowledge the clearance results in cancellation of the clearance transaction and requires that Shanwick be contacted by voice. Upon receipt of the clearance acknowledgement, Shanwick sends a message to the aircraft confirming the clearance. If this message is not received, Shanwick must be contacted by voice. If the flight crew requests a new clearance or if Shanwick requires a change to an existing clearance, one or more reclearances may be received by the flight crew. These reclearances are annotated RECLEARANCE 1, RECLEARANCE 2, etc., although may not necessarily be numbered consecutively.

G450 Procedures: Oceanic Clearance from a DSP

How you get a data link oceanic clearance everywhere in the world except from NY Center

[G450 Aircraft Operating Manual, §2B-21-40, ¶2.F.] Delivery of oceanic clearances by way of datalink for eastbound transatlantic flights is available from Gander Area Control Centre (ACC) to EPIC CMF-equipped aircraft. The aircraft, including any variable call signs, must be registered through the GDC with Gander. When flight planning, ensure that the phrase AGCS EQUIPPED (AGCS is an acronym for air-to-ground communication system) is included in the ATC remarks section of the filed flight plan. This remark informs Gander ACC that the flight crew desires to receive the oceanic clearance by way of datalink.

The book says to add "AGCS EQUIPPED" for coast out with Gander and we've always done it that way. This apparently inhibits your CPDLC Acknowledge function and will end up with you having to do a voice readback. SATCOM-Direct recommends you leave it out in a G450 or G550.

More about this: SATCOM-Direct AGCS Memo.

All oceanic areas, except New York, deliver oceanic clearances through a data link service provider, not CPDLC. For Gander, if you have filed "RMK/AGCS EQUIPPED" in item 18 of your flight plan, the clearance will come unsolicited. For all others, you download these clearances through the Aeronautical Operational Communication (AOC) page of the FMS by pressing the DLK key:

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Photo: MCDU AOC (DLK) Menu, from Eddie's aircraft.

Press ATS (LSK 2R)

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Photo: MCDU ATS Menu, from Eddie's aircraft.

Select OCEANIC REQ (LSK 4L)

These AOC services are known by most airlines as ACARS. The Air Traffic Services Menu is where you will find oceanic options.

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Photo: MCDU CLX Page, from Eddie's aircraft.

The ENTRY POINT and ENTRY TIME blanks are mandatory. The REQ MACH and REQ FL are taken from the FMS and may be changed if needed.

Once the mandatory entries are made you will get at SEND prompt at LSK 6R. Pressing SEND will result in a "SENT" line with the time.

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Photo: MCDU Oceanic Clearance, from Eddie's aircraft.

When the clearance is received the scratch pad will say "ATC MESSAGE" and then pressing DLK will give you the clearance page.

Acknowledge the clearance and print.

Performance Initialization

G450 Procedure: Performance Initialization

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Photo: MCDU PERF INDEX 1, from Eddie's aircraft.

Select the PERF INDEX by pressing the PERF key.

Select PERF INIT (LSK 1L).

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Photo: MCDU PERFORMANCE INIT 1, from Eddie's aircraft.

Select the next page by pressing NEXT.

[G450 Aircraft Operating Manual, §2B-26-30, ¶1.]

  • 1L — Aircraft Type (ACFT TYPE) is displayed on this line. No entry is permitted here. The aircraft type is loaded from the aircraft database. If no aircraft database has been loaded, this line is blank. An aircraft database must be loaded in order to select the FULL PERF option. Normally, an aircraft database needs to be loaded only when the FMS is installed. The aircraft database is retained from flight to flight and updated by the learning process. The pilot should verify that the ACFT TYPE data field has the correct aircraft type. The system generates incorrect performance predictions if the FMS contains the wrong AIRCRAFT DB.
  • 1R — Aircraft tail number (TAIL #) is displayed on this line. The tail number must be entered in this field before going to the next page. Once entered, it is saved. No action is required on future flights.
  • 2L — The FMS has three PERF modes or methods of performance calculations. Use the OR prompt at 2R to change the modes
    • When CURRENT GS/FF (groundspeed/fuel flow) is selected, performance calculations are based on current groundspeed and current fuel flow. However, while on the ground, the FMS default groundspeed is used. This groundspeed is displayed at 1Ron the first page of any stored flight plan. Once airborne, the current groundspeed is used. The current fuel flow is displayed at 1R of the FUEL MGT 1/2 page. However, the value can be overridden by a pilot entry. The overridden value is then used.
    • Selecting PILOT SPD/FF bases performance calculations on pilot-entered speed schedules and cruise fuel flow. When using this option, the cruise fuel flow must be entered at 2R on the PERFORMANCE INIT 2/4 page. Automatic adjustments are made for the higher fuel flow in climb. Entered winds and sensed winds (once airborne) are included in the groundspeed predictions used for time en route estimates.
    • Selecting FULL PERF bases performance on pilot selections and the aircraft performance. An aircraft database must be loaded before this option is available

    I can think of only one scenario where you would not use FULL PERF: if the performance database was missing.

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Photo: MCDU PERFORMANCE INIT 2, from Eddie's aircraft.

Select the next page by pressing NEXT, unless you want to make a change to the indicated speeds.

[G450 Aircraft Operating Manual, §2B-26-30, ¶1.]

  • 1L and 3L — The climb and descent speed schedules are always displayed as both a calibrated airspeed (CAS) and a MACH. Changes can be made by entering a CAS, a MACH, or both separated by a slash (/). The leading slash (/) is used as an option when entering a MACH only. Entering *DELETE* returns the default climb or descent speed schedule. The active speed command is the CAS at lower altitudes and MACH at higher altitudes. The crossover altitude is where both the CAS and the MACH translate to the same true airspeed (TAS). The FMS always uses the CAS or MACH entry that provides the lowest TAS at the current altitude.
  • 2L — The cruise speed schedule can be a CAS/MACH pair, only CAS, only MACH, or a system-generated cruise speed schedule. Entries of a CAS, a MACH, or both are accepted. Entering *DELETE* returns the default cruise speed schedule which is LRC in FULL PERF and the value from the aircraft database (or 300/.80) in CURRENT GS/FF or PILOT SPD/FF. The two other system-generated schedules, MAX SPD, MAX END and MXR SPD, can be selected on the CRUISE MODES page only. If both a CAS and MACH are entered, the active speed command is the CAS or MACH that provides the lowest TAS at the current altitude. If the LRC or MAX SPD schedules are active, the speed command is issued as a MACH at higher altitudes and a CAS at lower altitudes. This is determined by the VMO/MMO crossover altitude. If the cruise speed schedule is MAX END, the speed command is always CAS.

The defaults work well but you may consider reducing the descent angle from 3.0 to 2.5 degrees if your ATC environment permits it. The G450 cannot descend at 3.0° at high altitude without picking up speed or introducing extra drag.

More about this: G450 Performance (Descent).

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Photo: MCDU PERFORMANCE INIT 3, from Eddie's aircraft.

Select the next page by pressing NEXT, unless you want to make a change to the step increment, fuel reserve, or to/ldg fuels.

[G450 Aircraft Operating Manual, §2B-26-30, ¶1.]

  • 1L — Entries for step increment must be in thousands of feet. The three trailing zeros can be omitted. For example, a 4000 ft step climb increment can be selected by entering 4 or 4000. Entering *DELETE* returns the selection to no step or zero feet. Step climbs are used for long range flights to optimize the aircraft performance. As the aircraft burns fuel, the optimum altitude goes up. If a step increment is selected, the FMS computes the bottom of step climb (BOSC) point. The BOSC is where the aircraft is light enough to climb by the amount of the step increment to a new cruise altitude. More than one step climb can be calculated for a flight. When a step increment is selected, time and fuel predictions assume that the step climbs will be made. Therefore, a step increment should only be selected when the intent is to make the step climbs. If clearance is not given or the step climb is not going to be made, step increment should be set to zero in order to maintain accurate time and fuel predictions.
  • You will almost never be permitted a step climb on your terms so you should probably leave this number alone. We used this in the GV rather than look at "Check Fuel Remaining" messaged for the first few hours. If you use this feature, you just have to be aware that there are caveats to your fuel planning.

  • 2L — The method of calculating fuel reserve is displayed on this line. Entering *DELETE* returns to the default reserve mode which is National Business Aircraft Association (NBAA) rules.
    • The NBAA fuel reserve requirement is the sum of the two following items:
      1. Fuel required to fly the alternate flight plan (from the destination to the alternate destination). If the alternate flight plan is less than 200 NM or if there is no alternate flight plan, the NBAA standard 200 NM alternate flight plan is assumed.
      2. Fuel required to hold for 30 min at 5000 feet at the reserve holding speed at the alternate.
    • A fuel reserve in pounds can be entered. The specified fuel reserve applies at the destination, or at the alternate destination if one has been entered.
    • A fuel reserve in minutes can be entered. The time entered is converted to pounds of fuel assuming flight at 5000 feet at the reserve holding speed. The fuel reserve applies to the destination or the alternate destination if one has been entered.
  • 3L — The default values of takeoff/landing fuel (TO/LDG FUEL) are supplied from the aircraft database. However, manual entries can be made. Manual entries are saved for the next flight. Entering *DELETE* returns the default values. The takeoff fuel allowance includes fuel burn for taxi and takeoff. Takeoff fuel allowance is decremented by fuel flow. However, it is not decremented past zero. Following takeoff or when the takeoff allowance has been decremented to zero, fuel remaining values are adjusted to account for actual fuel burned. The takeoff fuel allowance is added to the fuel required calculation. The fuel required calculation is the predicted fuel from takeoff to landing plus reserves. The landing fuel allowance is a buffer amount of fuel that the FMS incorporates into the total fuel required computation. The landing fuel is intended to cover the ground operation after landing. The value can be changed at any time.
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Photo: MCDU PERFORMANCE INIT 4, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-30, ¶1.]

  • 1L — The transition altitude can be entered here. The FMS uses the input to determine how to display altitudes. Altitudes above the transition altitude are displayed as flight levels (FL) and below in feet. Entering *DELETE* returns the default value of 18,000 feet.
  • This entry has nothing to do with when you get the "Check Transition Altitude" warning, only when the FMS decides to list an altitude in feet or flight levels.

  • 1R — Speed limits associated with altitudes, not waypoints, can be entered. For U.S. operation, 250 knots below 10,000 feet is entered. The FMS speed command is limited to this speed below the restriction altitude. Entering *DELETE* removes the speed/altitude limit and displays dashes. This is the only field that can be left with dashes and still allow performance data to be computed.
  • 2L — INIT CRZ ALT (Cruise Altitude) -- The initial cruise altitude is entered at this location. The FMS uses the initial cruise altitude to determine the altitude where the cruise phase of flight commences. The FMS changes the speed command and EPR rating from climb to cruise when the aircraft levels at the initial cruise altitude or higher. The default for INIT CRZ ALT is OPTIMUM if the performance mode is FULL PERF. The FMS calculates the optimum cruise altitude based upon the performance initialization data. After performance initialization is completed, the calculated optimum altitude is displayed in small characters on this page. The method used to compute the initial cruise altitude is displayed following the altitude.
  • You should always enter your planned initial level off altitude here. The FMS will not sequence to cruise mode until you reach this altitude.

    More about: Optimum Altitude.

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Photo: MCDU PERFORMANCE INIT 5, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-30, ¶1.]

  • 1L — Basic operating weight (BOW) is retained in memory but it should be verified on each flight. A new entry can be made at any time. Entering *DELETE* returns the entry prompts.
  • 2L — The fuel weight, when sensed by the fuel quantity system, is displayed in small characters. The pilot can manually enter a fuel weight which is displayed in large characters.
  • 3L and 1R — Cargo weight and passenger count must be entered in order to compute performance data. The average weight per passenger can also be adjusted by entering a slash (/) followed by the weight (e.g., /200).
  • 6R — When performance initialization is complete, the CONFIRM INIT prompt is displayed in the lower right corner of this page. The CONFIRM INIT prompt must be selected for the performance function to calculate performance data and for the VNAV function to be available. Selecting the CONFIRM INIT prompt displays the PERF DATA page. After confirming initialization, the prompt at 6R of the PERFORMANCE INIT page becomes PERF DATA on all PERF INIT pages.

Once you've initialized the performance, you will never see the CONFIRM INIT prompt again unless you start over. From this point, changes to parameters will result in instant changes to output calculations.

Optimum Altitude

[G450 Aircraft Operating Manual, §2B-26-30, ¶1.]

  • The optimum altitude has different definitions based on the cruise speed mode. For the LRC and manual cruise speeds, the optimum altitude is where the specific range is optimized. This altitude is typically close to the ceiling altitude. The MAX SPD optimum altitude is where true airspeed is maximized. This altitude tends to be close to the VMO/MMO crossover altitude. For MAX END speed, the optimum altitude is where the fuel flow is minimized. For MXR SPD, the optimum altitude is where true airspeed is maximized while ensuring the destination can be reached based on fuel quantity.
  • The OPTIMUM altitude is short-trip limited. This means the computed altitude is adjusted downward if the flight is not long enough for a climb to the optimum altitude. Regardless of short-trip limiting, the cruise altitude is always set at least as high as the altitude selector.

The altitude labeled as "Optimum Altitude" is almost always a lie. You rarely, if ever, fly at LRC, MAX SPD, or MAX END. And even if you did, setting the Altitude Selector above the computed altitude overrides it.

Pre-Departure Clearance (PDC)

The G450 Pre-Departure Clearance (PDC) request depends on your main operating software version. The following is based on having ASC 910 installed, so it isn't documented in the current (Jan 2014) aircraft operating manual. What about a domestic CPDLC Departure Clearance instead? See: PDC versus DLC.

PDC Explained

[G450 Aircraft Operating Manual, §2B-21-40, ¶2.E.]

  • PDCs are departure clearances received by way of datalink and are available at many airports in the United States to PLANEVIEW CMF-equipped aircraft. The aircraft, including any variable callsigns, must be registered through the GDC with the FAA, and ARINC. Use of PDCs at participating airports is mandatory once registered. Refer to the list of participating airports at the end of this section.
  • A PDC is based on a filed instrument flight rule (IFR) flight plan, regardless of whether the flight plan was filed by the GDC, through a flight service station (FSS), or by way of direct user access terminal service (DUATS). Approximately 20 min prior to the filed time of departure of the flight plan, ATC will generate and then forward the PDC to the GDC for storage. With this in mind, request the PDC no earlier than 15 min prior to the filed time of departure. Because this short time is often insufficient to receive the clearance and depart as planned, the GDC recommends filing the flight plan with a time of departure 30 min earlier than the actual intended time of departure. Refer to the PDCs procedure described later in this section for detailed instructions to request a PDC.
  • If the GDC has received the PDC from ATC, the PDC is sent to the aircraft as a datalink message. If the GDC has not received the PDC from ATC, a datalink message indicating that the PDC has not been received from ATC and that the PDC may be requested again in 5 min is sent to the aircraft. Multiple PDC requests can be sent until 10 min prior to the filed time of departure.
  • Once the PDC is received, the flight crew is required to follow the clearance. Be sure to page forward through the clearance until END OF CLEARANCE is displayed. An aircraft can receive only one PDC per airport per day and a PDC will not be available if there is any change to the filed route and/or altitude or if the clearance needs to be negotiated. A PDC is valid for 2 hr beyond the filed time of departure.

It is up to the airport tower facility to actually send the PDC, they seem to do this about 30 minutes prior to your filed time.

G450: Requesting PDC (Departure Clearance)

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Photo: AOC Menu Page, from Eddie's aircraft.

Press the DLK key to access the AOC Menu Page.

AOC is "Aeronautical Operational Communications" and refers to any communications between you and your data service provider, usually ARINC or GDC.)

Select ATS (LSK 2R)

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Photo: ATS Menu Page, from Eddie's aircraft.

Select DCL REQ (LSK 3L)

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Photo: DCL Request Page Blank, from Eddie's notes.

Enter the flight ID at LSK 1L. Note the default format will be - - - / - - - where you appear to be given the option of entering three characters either side of a slash. You enter your flight ID as follows:

  • For a flight ID with three characters enter ##/#, for example N1A would be N1/A
  • For a flight ID with more than three characters enter ###/##, for example N1234A would be N12/34A

In the drawing, N7700 is entered N77/00.

The page should remember your FLT ID from one flight to the next.

The ATIS can be A for arrival or D for departure.

Notice the STAND entry at LSK 2R is blank. You will not get an asterisk at LSK 6R until you fill this out with something, even if you have to make the something up.

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Photo: DCL Request Page Ready, from Eddie's notes.

With a stand number of 0, the asterisk at LSK 6R appears and we can request our PDC. I've also used "FBO" as the stand and that worked too.

SATCOM Voice Call

You can contact most oceanic radio centers for any emergency or non-routine situation, but most of these are accessed by a 6-digit "short code." You can dial a short code or a regular voice number through any of the MCDU's.

Make a SATCOM Short Code Call

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Photo: MCDU Menu Page, from Eddie's aircraft.

Select the Menu Page with the MENU key.

From this page select the SATCOM Main Menu by pressing LSK 6L.

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Photo: MCDU SATCOM Main Menu Page, from Eddie's aircraft.

Select the directory with LSK 6R

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Photo: MCDU SATCOM Directory with 431613 In Scratch Pad, from Eddie's aircraft.

Type in the desired short code. We are using 431613, the short code for Gander Radio, in the example.

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Photo: MCDU SATCOM Directory Dialing 431613, from Eddie's aircraft.

If the number is in a valid format, you will see the number displayed with "DIALING." To end the call, press LSK 2R.

Example Oceanic Numbers

The oceanic numbers are given on some en route charts and are reproduced here:

  • Gander Radio: 431613
  • New York Radio (ARINC): 436623
  • Iceland Radio (Emergency): 425101 or 425103
  • Iceland Radio (Com Failure): 425105
  • Santa Maria Radio: 426305 or 426302
  • Shanwick Radio: 425002

Dial a Regular Voice Number using an MCDU

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Photo: MCDU SATCOM Directory Dialing 017096515212, from Eddie's aircraft.

You can make calls to regular voice numbers, those that are not 6 number short codes, by formatting the number as you would an international phone call. Since our aircraft is based in the United States, a call to Gander Radio which appears as 1-709-65155212 would be entered into the scratch pad as 017096515212.

Making the Call

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Figure: G450 Audio Control Panel, from G450 Aircraft Operating Manual, §2B-22-40.

[G450 Aircraft Operating Manual, §2B-22-40.]

  • To interface with the SATCOM transceivers the audio panel is used to to select the SATCOM system and adjust the volume of the received audio. When communicating using the SATCOM system, the audio panel has annunciators that indicate an incoming call, a call on hold, and when a call is being connected. SATCOM can also be used to make a call.
  • The two SAT buttons are used to control the SATCOM telephone system. The rectangular button flashes and a chime sounds to indicate an incoming SATCOM call. Both the round and rectangular buttons remain on when the line is in use. The rectangular button is used to connect and disconnect the SATCOM calls. The pilot disconnects SATCOM by pushing the rectangular button again. At this time, all SATCOM annunciator lights go off.

Set RNP

The Required Navigation Performance (RNP) on your Pilot Flight Display is set automatically by the FMS to agree with the airspace you are flying and the phase of flight (depature, en route, appraoch) and you will rarely need to adjust it. But, for example, you are flying a narrow navigation cooridor and want to be alerted well before getting out of limits, setting a lower value can be useful. When you exceed to limits, the RNP display and the course deviation indicator turn amber.

FMS Procedure: Set RNP

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Photo: MCDU Progress 1 Page, from Eddie's aircraft.

Select Progress 1/3 (Press PROG key)

Select Progress 2/2 (Press NEXT)

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Photo: MCDU Progress 2 Page, from Eddie's aircraft.

Select RNP (Press LSK 6L)

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Photo: MCDU RNP Settings Page, from Eddie's aircraft.

Enter your desired RNP into the scratch pad.

Press LSK 1L

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Photo: MCDU RNP Settings Page, from Eddie's aircraft.

The new RNP setting (0.50 in our example) should appear at LSK 1L.

The settings reported in the other positions are automatically used when the conditions are correct. All of these are self explanatory except the "RAD" postion, which is the default RNP value used on FMS approaches overlaying "radio" approaches, such as a VOR or NDB approach that does not include "GPS" in the title.

SBAS Settings

The Spaced Base Augmentation System (SBAS) is your GPS fine-tuned and will allow you to fly an LPV approach, so you want it. Its presence is checked on the FMS Progress page and will be see as "GPS-D" and incredibly small EPUs.

SBAS Explained

[G450 Aircraft Operating Manual, §2B-08-120, ¶27.] The Space-Based Augmentation System (SBAS) is the implementation of a ground sensor-generated correction signal transmitted to an SBAS-equipped GPS receiver by way of a geosynchronous satellite. Several countries and/or groups of countries are developing their own SBAS system with their own respective names. The SBAS systems in development at this time are as follows:

  • Wide Area Augmentation Systems (WAAS) for the United States and Canada
  • European Geostationary Navigation Overlay System (EGNOS) for Europe
  • Multifunction transportation Satellite-based Augmentation System (MSAS) for Japan.

Although several SBAS systems are currently under development, they are all expected to be compatible and interoperable.

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Photo: MCDU Progress Page 1, GPS-D, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-32-70, ¶1.] GPS-D is GPS with SBAS. The availability of GPS-D and GPS are mutually exclusive, and GPS-D is dependent on the presence and reception of the SBAS signal. When the SBAS signal is present, and the GPS sensor is the selected sensor for the FMS, then the annunciator on PROGRESS page 1 is GPS-D. If no SBAS signal is present, then the annunciator on PROGRESS page 1 is GPS.

FMS Procedure: Check SBAS

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Photo: MCDU NAV Index 1 Page, from Eddie's aircraft.

Select NAV Index 1/2 (Press NAV key)

Select NAV Index 2/2 (Press NEXT)

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Photo: MCDU NAV Index 2 Page, from Eddie's aircraft.

Select MAINTENANCE (Press LSK 2R)

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Photo: MCDU Maintenance Page 1, from Eddie's aircraft.

Select MAINTENANCE 2 (Press NEXT)

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Photo: Maintenance Page 2, from Eddie's aircraft.

Select SETUP (Press LSK 6L)

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Photo: MCDU FMS Setup, from Eddie's aircraft.

Select FLIGHT CONFIG (Press LSK 1R)

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Photo: MCDU FLIGHT CONFIG Page 1, from Eddie's aircraft.

Select FLIGHT CONFIG Page 2 (Press NEXT)

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Photo: MCDU FLIGHT CONFIG Page 2, from Eddie's aircraft.

Ensure the following:

  • TEMP COMP CONFIG - COLD
  • HYBRID - ON
  • SBAS - ON

SBAS GPS Deselection

[G450 Aircraft Operating Manual, §2B-32-70, ¶2.B.] Disabling of the SBAS augmentation aspect of the GPS receivers is performed on the FLIGHT CONFIG page 2. Pushing LSK 5R on the FLIGHT CONFIG page 2 turns the SBAS selection on or off. Turning the SBAS selection off sends a signal to the GPS receivers to stop using SBAS augmentation. SBAS augmentation for each GPS sensor cannot be individually deselected. When the SBAS switch is OFF, the GPS sensors continue to output a non-augmented GPS position, with correspondingly larger EPU and RAIM values. Turning the SBAS augmentation OFF on the FLIGHT CONFIG page has no effect when an RNAV approach with LPV minimums is loaded into the FMS and the GPS receiver is in SBAS-PA mode (displayed as APPROACH on the GPS status page).

Sensor Logic

Since the dawn of what we considered high performance long range navigation, when GPS became standard equipment, we preached the navigation priority: GPS, DME/DME, VOR/DME, and then IRUs. Well, all that has changed with Hybrid IRUs. But how those fall back from GPS is less than clear. You are more likely to see GPS, Hybrid IRUs, DME/DME, and then VOR/DME. After a lot of discontent from the masses, in late 2012, Honeywell set the record straight. Most of their explanation is quoted verbatim here.

Before Hybrid IRU's

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Photo: MCDU Progress Page 1, GPS, from Eddie's notes.

[Honeywell DirectTo, 2012 Q4] Prior to FMS 7.1 ( EPIC) and 6.1 (FMZ 2000), the FMS uses a linear hierarchy to determine which sensor should be used for navigation. If the EPU value of any sensor is deemed unacceptable by the FMS, then it will 'fail down' to the next available sensor. The fail down logic in older software versions uses the following hierarchy:

  1. GPS
  2. DME/DME
  3. VOR/DME
  4. IRS (if installed)
  5. Dead Reckoning

The Gulfstream manuals don't say this. In fact, the only reference in the GV series is in the classic GV AFM Limitations when talking about RNP-10. Nevertheless, this is the way Honeywell says it worked on these older systems.

Hybrid IRU Position Sensor

[G450 Aircraft Operating Manual, §1-34-30, ¶7] The selected sensor for the FMS position is chosen by comparing the EPU values of all available sensors that have not been deselected by the pilot, and choosing the sensor with the lowest value. Sensor accuracy is the produced Figure of Merit (FOM) for GPS and Hybrid IRU, and the computed EPU for IRS drift and radio position. Once a sensor is selected, that sensor remains selected unless the EPU of another sensor is at least 5% lower than the EPU of the selected sensor. For an instrument approach selected from the NAV database, the selected sensor functions in one of two ways: When the database record indicates that the chosen approach has a required sensor (e.g., GPS required), then that sensor is locked as the selected sensor at three miles from the FAF and remains the selected sensor throughout the approach. When the database record does not indicate that the chosen approach has a required sensor, the sensor with the best accuracy when the aircraft is three miles from the FAF is locked as the selected sensor for the remainder of the approach.

[G450 Aircraft Operating Manual, §2B-32-70]

  • The FMS uses a performance based sensor selection scheme that uses the EPU of each sensor to select the best performing sensor. The GPS sensors and the Hybrid IRS function produce a figure-of-merit (FOM), which is used as the EPU value for those sensors. The EPU is modeled by the FMS for the IRS, DME/DME, and VOR/DME sensors. The sensor currently selected for use is displayed on the PROGRESS page 1.
  • The available FMS sensors for selection are as follows:
    • Hybrid IRS
    • GPS-D
    • GPS
    • IRS
    • DME/DME
    • VOR/DME
    • Degrade
    • DR

    Note: GPS-D is GPS with SBAS. The availability of GPS-D and GPS are mutually exclusive, and GPS-D is dependent on the presence and reception of the SBAS signal. When the SBAS signal is present, and the GPS sensor is the selected sensor for the FMS, then the annunciator on PROGRESS page 1 is GPS-D. If no SBAS signal is present, then the annunciator on PROGRESS page 1 is GPS.

The FMS will use the sensor with the lowest EPU and continue to use that until another sensor beats it by 5%. Normally that would only be a contest between GPS and the Hybrid IRU. But there have been documented cases where that wasn't true. Honeywell finally addresses this in 2014 . . .

With Hybrid IRU's

[Honeywell DirectTo, 2012 Q4]

    images

    Photo: MCDU Progress Page 1, GPS-D from Eddie's aircraft.

  • As Performance-Based-Navigation (PBN) becomes more prevalent throughout worldwide airspace, Honeywell has modified the logic of the EPIC and FMZ 2000 FMS systems to ensure that the best sensor is being used for navigation. Sensor accuracy and integrity is generally measured by the Estimated Position of Uncertainty (EPU). An EPU is assigned for each sensor that is available to the FMS, and is calculated using various means.
  • With software versions 7.1 (EPIC) and 6.1 (FMZ 2000), the FMS chooses the best available sensor based on the lowest EPU. “Best” sensor means that, if the current sensor in use is at least less than 5% worse than any other sensor, the FMS will continue to use it as long as it meets all validity checks. In other words, for the FMS to use another sensor, the new sensor has to be performing at least 5% better than the sensor currently in use. The exception is when DME/DME or VOR/DME is being considered. In this case, a radio source must have an EPU least 40% better than a GPS or IRS EPU to be considered for navigation.
  • This is breaking news: DME/DME and VOR/DME will not be called upon until they are significantly better than GPS or the IRU's. Given the IRU's have become so good, you are more likely to see HYBRID or IRS as a sensor choice.

    images

    Photo: MCDU Progress Page 1, GPS-D from Eddie's aircraft.

  • The incorporation of this new logic also means that crews are more likely to encounter IRS Navigation mode because the newer Hybrid Inertial Reference Units are constantly being updated by the GPS, and generally have a lower EPU than DME/DME. Additionally, the inclusion of SBAS will yield an even lower EPU for the IRS. Subsequently, if the GPS EPU rises to a value that is 5% worse than the IRS EPU, then IRS will be used by the FMS. For example, if the aircraft is using GPS with SBAS (GPS-D mode) with an EPU of 0.01, then the IRS should also have a similar EPU because its position is constantly being updated with the D-GPS position. If, however, the SBAS signal is lost, the GPS sensor would immediately increase to a higher value (e.g., .11). It is then possible that the system would revert to IRS for a short period because the IRS EPU would be better than the normal GPS EPU. As a result of IRS coasting, the IRS EPU would then grow to match the GPS EPU; then the FMS would resume using normal GPS. If normal GPS is then lost, the FMS will continue to coast in IRS Navigation mode until it is 40% better than the IRS EPU.
  • Whenever the EPU value exceeds the RNP value for a given phase of flight, various CAS messages or FMS messages will be annunciated. Additional CAS messages may also be annunciated if the EPU reaches an unacceptable level to conduct an RNAV approach, regardless of phase of flight. For example, when operating in terminal airspace, the EPU would have to exceed 1.0 in order to receive an “UNABLE RNP” Message. Additionally, if the EPU reaches a value above 0.5, other CAS Messages are annunciated on certain EPIC platforms, alerting the crew that an RNAV approach may not be possible. It is important to note that automatic reversion to IRS due to GPS issues will not generate a CAS message until the IRS EPU reaches a level above the current or next leg RNP value. Flight crews should review their OEM guidance to determine applicable CAS messages and associated flight crew procedures.

Takeoff Data Initialization

The takeoff initialization routine depends on several steps before you get to the appropriate page on the FMS, and if any of those steps are missing, you won't get the numbers on the display controller you need. It pays to be methodical.

See: Performance Initialization.

The performance computer assumes you are going to lose an engine at V1 and will constrain your maximum takeoff weight based on engine-out performance. You may have better options.

See Departure Obstacle Avoidance.

G450 Procedure: Takeoff Initialization

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Photo: MCDU Perf Index Page 1, from Eddie's aircraft.

Select PERF > TAKEOFF (LSK 2R)

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Photo: MCDU Takeoff Init Page 1, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.A.]

  • Aircraft type (1L)
  • Certification agency or rules (2L)
  • Software version identification (2R)
  • Takeoff/Landing mode (3L).
  • No entries are made on this page.

Select the next page by pressing the NEXT key.

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Photo: MCDU Takeoff Init Page 2, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.A.]

  • 1L — The selected runway identifier is displayed. If no runway has been selected on the DEPARTURE pages, the field displays dashes. Entries are permitted and can be made using the 2-digit identification (e.g., 29 meaning 290°). Entries in degrees require a 3-digit input. Selection of 1L, with no entry in the scratch pad, results in display of the DEPARTURE page.
  • You are better off selecting the runway from the DEPARTURE pages as a cross check of having the correct runway data and when you get taxi to the runway in question, having one more needle line up in the correct direction to confirm you are about to takeoff where you intended.

  • 1R — The available runway length and its magnetic heading is displayed. If no runway has been selected, entry prompts are displayed. An entry of runway length can be made to override the database information or supply the length when the runway is not in the database. Note that the actual takeoff and landing length of a runway can differ from the FMS database due to displaced threshold, stop way, or temporary relocated threshold.
  • 2L — The FMS computed slope of the runway is displayed. The FMS computes the slope by taking the elevation of the far end of the runway minus the elevation of the near end of the runway and dividing by the runway length. Positive slopes are shown with an up arrow (↑). Negative slopes are shown with a down arrow (↓). If no runway has been selected, entry prompts are displayed. An entry of slope can be made to override the database information or supply the slope when the runway is not in the database.
  • 2R — The runway width, if available from the database, is displayed. An entry for displaced threshold can be made on this line. The default displaced threshold entry is 31 meters or 100 feet.
  • 3L and 3R — An entry for runway clear way and stop way can be entered on these lines. The clear way is used in computing the available runway for accelerate and go. The stop way is used in computing the available runway for accelerate and stop. The stop way distance from the navigation database is displayed as the default value. The clear way default value is zero meter.
  • More about this: Runway Data.

  • 4L — The sensed static air temperature is displayed in this field. Under normal circumstances, the sensed temperature should be used. However, an entry can be made for cases where the predicted temperature for takeoff is different than the current sensed temperature. An entry can be made in degrees Celsius. Entries in degrees Fahrenheit require a leading slash (/).
  • 4R — The surface wind is a required entry on this page.
  • 5L and 5R — The computed pressure altitude and barometric (BARO) setting are displayed on this line. Also displayed is the runway elevation from the database. While entries are permitted for all these items, no entries are normally made. The only recommended entry is elevation in the case where the runway is not in the database. Entry of BARO setting is permitted and can be made in inches of mercury or millibars. Use *DELETE* to return to the default value and units. When a runway has been selected, the pressure altitude is computed based on the field elevation and the BARO setting. If an entry of pressure altitude is made, elevation is computed using the BARO set.

Select the next page by pressing the NEXT key.

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Photo: MCDU Takeoff Init Page 3, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.A.]

  • 2L and 2R, 3L and 3R, 4L and 4R — An entry of obstacle distance from the departure end of the runway and elevation can be made on these lines. The default is NONE. Depending upon the configuration, obstacle distance entries can be in either feet, meters or nautical miles. Entries in nautical miles require a leading slash (/).
  • This can be a misleading page because of the "DIST(FT /NM)" which "means distance of the obstacle from the end of the runway expressed in feet OR nautical miles." The next section refers to feet PER nautical mile, don't let that fool you.

    Enter up to three obstacles using the left keys for the distance from the end of the runway and the right keys for the elevation of those obstacles in feet MSL. The performance computer will constrain your maximum takeoff weight based on engine-out performance. You may have better options. See Departure Obstacle Avoidance.

  • 5L and 5R — An entry of a standard instrument departure (SID) gradient in FT/NM, from the departure end of the runway, and elevation in FT MSL is made on this line. The default is NONE.
  • This SID gradient is expressed in feet PER nautical mile. Once again, the performance computer will constrain your maximum takeoff weight based on engine-out performance. You may have better options.

    See Departure Obstacle Avoidance.

Select the next page by pressing the NEXT key.

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Photo: MCDU Takeoff Init Page 4, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.A.]

  • 1L and 1R — The selected engine bleeds setting for takeoff calculations is displayed at 1L. The default setting is OFF. Select the OR prompt at 1R to select other bleed settings. If the actual engine bleeds setting is different than the selected setting, this line is displayed in inverse video.
  • This appears to be a carry over from the G550 where it is possible to do a "bleeds off takeoff," which is not an option in the G450. Here our prompt is "ANTI-ICE" and the default condition is "OFF." The choices:

    • OFF — No anti-ice will be used for takeoff.
    • COWL — Only engine cowl anti-ice will be used for takeoff.
    • COWL & WING — Engine cowl and wing anti-ice will be used for takeoff.

    If COWL and/or WING anti-ice is planned, it will appear in inverse video as these system would be off at this point in the checklist.

  • 3L and 3R — The selected spoiler setting for takeoff calculations is displayed at 3L. The default setting is OPERATIVE (auto spoilers). The setting can be changed at 3R to INOP (manual spoilers). If the actual spoiler setting is different than the selected setting, this line is displayed in inverse video.
  • You will normally see the OPERATIVE in inverse video at this point, since you are probably planning on using them but they are off at this point in the checklist.

  • 4L and 4R — The selected antiskid setting for takeoff calculations is displayed at 4L. The default setting is OPERATIVE. The setting can be changed at 4R. If the actual antiskid setting is different than the selected setting, this line is displayed in inverse video.
  • 5L and 5R — The selected runway condition for takeoff calculations is displayed here. The setting can be changed at 5R. The default is DRY.

Select the next page by pressing the NEXT key.

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Photo: MCDU Takeoff Init Page 5, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.A.]

  • 1L and 1R — The BTMS configuration is displayed at this line. When ENABLED, brake temperature computations are used in computing the TAKEOFF DATA. When DISABLED brake temperature computations are not used in computing the TAKEOFF DATA. The default is ENABLED. Should the FMS not be able to perform brake temperature monitoring computations, ENABLED is displayed in inverse video.
  • If the ENABLED appears in inverse video it may be that the BTMS lost the time and date of the previous braking effort. (The peak temperature for one or more of your brakes will be dashed out in the 1/6 brakes page.) As long as you are sure the brakes are sufficiently cool for the takeoff, you can disable the BTMS. They will record the subsequent peak brake temperatures and will re-enable themselves.

    See: G450 Landing Gear & Brakes / Brake Temperature Monitoring.

  • 2L and 2R — The selected thrust mode for takeoff calculations is displayed at 2L. The default setting is RATED EPR. Select 2R to change the setting. RATED EPR is defined in the AFM as using full takeoff thrust. The FMS calculates takeoff data for the available field length based on the takeoff EPR rating and V1 between V1MAX and V1MIN on the TAKEOFF DATA pages. FLEX is defined in the AFM as reduced takeoff thrust. This power setting is calculated observing all the limitations in the AFM. The FMS calculates takeoff data for the available field length based on reducing EPR as much as possible (but not more than 0.154 EPR less than RATED EPR, and not less than 1.39 EPR). The pilot can select any V1 between V1MAX and V1MIN on the TAKEOFF DATA pages.
  • 3L and 3R — The selected flap setting for takeoff calculations is displayed at 3L. The default setting is 20_. The setting can be changed at 3R. If the actual flap setting is different than the selected setting, this line is displayed in inverse video.
  • 4L — The takeoff gross weight is displayed on this line. The takeoff weight is the gross weight from PERF INIT page 5. An overriding manual entry is permitted on this page. The default takeoff weight can be restored by entering *DELETE*. If the PERF INIT weights have not been entered, the T.O. WEIGHT line displays a prompt. If the weight changes during ground operations, the takeoff data is automatically calculated using the new weight unless a weight has been manually entered.
  • 6R — The CONFIRM INIT prompt is displayed when all required takeoff initialization items are entered. The CONFIRM INIT prompt must be selected to start takeoff data calculation. Changes made to takeoff initialization after selection of the CONFIRM INIT prompt are automatically recalculated without selecting CONFIRM INIT. In other words, selection of the CONFIRM INIT prompt is only required for initial calculation.
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Photo: MCDU Takeoff Data Page 1, from Eddie's aircraft.

If the takeoff initialization was successful, the Takeoff Data page will be displayed next.

Takeoff Data

With the exception of allowing you to select a V1 from a range of choices, the takeoff data pages report to you performance based on inputs from earlier pages. The V1 choices are simple enough, if you understand the difference between V1MIN and V1MAX. The climb performance charts, on the other hand, are a bit confusing.

Takeoff Data: Distances

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Photo: MCDU Takeoff Data, Page 1, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.B.]

  • The page title includes the selected thrust mode.
  • To change the thrust mode, select T.O. INIT (LSK 6L).

    See: G450 Takeoff Data Initialization.

  • Projected takeoff weight (1L)
  • This number is taken from the Performance Init 5/5 page.

  • Usable runway length (runway length minus displaced threshold) / AFM takeoff distance (1R)
  • The runway length comes from Takeoff Init 2/5 page, the runway required should be the greater of the accelerate-go and accelerate-stop distances given on line 3. In the example we have a balanced field condition.

  • Maximum takeoff weight for current configuration (2L)
  • I have not seen this line in our G450.

  • Takeoff runway wind condition (2R).
  • This is a component breakdown from the wind entered at Takeoff Init 2/5.

  • Accelerate-go and accelerate-stop distances (3L and 3R)
  • These two numbers come from the performance computer's computation of takeoff data which is based on the AFM. You can impact both by changing V1. More about this below.

  • Takeoff EPR (4L).

Accelerate-Go and Accelerate Stop Explained

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Figure: V1 Abort or Go, from Eddie's Notes.

[G450 Airplane Flight Manual, §5.1]

  • ACCELERATE-GO DISTANCE - the required distance to accelerate with both engines operating to the critical engine failure speed, sustain an engine failure, and continue the takeoff to a height of 35 feet AAL on a dry runway or 15 feet AAL on a wet runway.
  • ACCELERATE-STOP DISTANCE - the required distance to accelerate to V1, initiate actions to abort the takeoff, and come to a complete stop.
  • V1, TAKEOFF DECISION SPEED - the speed from which a decision to continue the takeoff results in a takeoff distance that will not exceed the available accelerate-go distance, or from which a decision and action to bring the airplane to a full stop will not exceed the accelerate-stop distance available. In the event of an engine failure, this speed takes account of the pilot recognition and reaction time of 1.0 seconds, including the pilot's first action after recognizing the engine failure. For an all-engine rejected takeoff, this is the speed at which the pilot performs his first action to abort.
  • The label "Decision Speed" is a bit misleading. The decision must have been made and the action to abort or continue must have been made by V1.

    More about this: V1 - Decision Action Speed.

  • VEF, CRITICAL ENGINE FAILURE SPEED - the airspeed at which either engine fails.

Takeoff Data: V1

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Photo: MCDU Takeoff Data, Page 2, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.B.]

Unlike previous Gulfstreams, the G450 performance computer defaults to a balanced field length. You can change that by selecting V1 (LSK 1L). Why would you want something other than BFL?

  • An Obstacle Rich Environment — If you've loaded the airplane to the point where you just barely make all climb restrictions, you may prefer to abort the takeoff if possible. Selecting V1MAX makes it more likely you will abort if an engine fails during takeoff, and if you lose an engine after this higher V1, you will have more speed to be beat those obstacles.
  • A Contaminated, Short Runway — If an aborted takeoff will require everything to work perfectly to get you stopped on the runway, you may prefer to take the airplane in the air and circle back to land with all of the runway in front of you. If so, selecting V1MIN makes it more likely you will be in "go mode" after an engine failure.
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Photo: MCDU V1 Select Page, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.B.]

  • The default value is V1BFL
  • 1L — This line displays the manually entered V1 speed. Any entry between MAX and MIN can be entered.
  • 2L and 2R — The MAX and MIN values of V1 are displayed. Selection can be made at either 2L or 2R.
  • 3L — The BFL V1 speed is displayed. This is the V1 speed at which the accelerate-go and accelerate-stop distances are equal. If V1BFL cannot be computed for the data entered on the TAKEOFF INIT pages, the line is blank. The default V1 is either V1MAX or V1MIN, whichever is closer to BFL.

Takeoff Data: Climb Performance

Minimum Level-Off Height Explained

[G450 Airplane Flight Manual, §5.6] The minimum level-off height is 1500 feet AAL. When multiple obstacles exist in the takeoff profile, the highest obstacle will dictate the minimum level-off height even if this is not the most demanding obstacle from a required gradient standpoint. If the horizontal distance is more than 120,000 feet from Reference Zero, the recommended level-off altitude must be determined as the sum of the obstacle height above Reference Zero plus the product of .008 times the horizontal distance from Reference Zero.

The performance computer does the math for you, so long as you only have three obstacles to enter. With more than three, you can either do the math for each or enter each in turn until you get the most restrictive answer.

Reference Zero Explained

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Figure: Reference Zero, from G450 Airplane Flight Manual, §5.1.

[G450 Airplane Flight Manual, §5.1] REFERENCE ZERO - a point on the runway or clear way plane at the end of the accelerate-go distance that is used as the reference point for an obstacle clearance analysis.

The 15 versus 35 foot height at reference zero is mandated by 14 CFR 25, §25.113 but is really insignificant for this discussion. What really matters is that it is measured at the end of the accelerate-go distance and could very well be thousands of feet before the departure end of the runway.

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Photo: MCDU Takeoff Data Example, Page 3, from Eddie's aircraft.

This can be a particularly misleading chart because of the green "*FROM REF 0" and "**FROM DER" line which leads you to believe the page is best understood as a left side and a right side, which is not true. It is best understood as a top half (MIN LVL OFF) and a bottom half (MAX LVL OFF). So that's how we'll cover it...

Minimum Level Off Height and Altitude

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Photo: MCDU Takeoff Data Example, Page 3, Top Half Only, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.B.]

  • 1L — The minimum gross Level-Off height from reference zero is displayed here.
  • Without an obstacle, this is usually, 1500' AGL. With an obstacle, it is usually, but not always, equal to the height of the obstacle.

    For the exceptions, see Minimum Level-Off Height Explained, below.

  • 1R — The minimum Level-Off altitude (altimeter indicated) is displayed here.
  • This is the same as figure at 1L adjusted for the elevation of the departure end of the runway and ISA temperature conditions. In the example there is no obstacle, the departure end of the runway is at 124', and the temperature is 2°C which results in a temperature correction for 1,500' of 67'. (So 1,500 + 124 + 67 = 1,691')

    More about: Altimeter Temperature Correction.

    A key point to understand is that both LSK 1L and LSK 1R are the same point in space.

  • 2L — The minimum gross gradient from reference zero is displayed here.
  • This gradient averages the curve of the airplane as it starts from 35' above the runway to the point referred to at LSK 1L, 15' if the runway is wet.

  • 2R — The minimum SID gross gradient from DER is displayed here.
  • This gradient is the line from the departure end of the runway to the point referred to at LSK 1R.

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Figure: Min Level Off Example, from Eddie's notes.

In our example, the aircraft arrives at its 1,500' AGL point (LSK 1L) via a curved arc as the single engine performance tapers off a bit with altitude. The average gradient of that arc comes to 6.0% (LSK 2L). The performance computer tells us that this point in space will be at 1,691' indicated altitude (LSK 1R), based on the departure end of the runway's elevation and the temperature correction off ISA. It is the exact same point in space. The performance computer draws a line from the departure end of the runway to this point and tell us it comes to 382 ft/nm (LSK 2R), which factors to a gradient of 6.3%. It makes sense that this would be a steeper gradient than LSK 2L, given it starts later and ends at the same point.

Maximum Level Off Height and Altitude

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Photo: MCDU Takeoff Data Example, Page 3, Bottom Half Only, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50, ¶3.B.]

  • 3L — The maximum gross Level-Off height from reference zero is displayed here. This value is based on a 10-minute limit on the use of takeoff thrust for single engine operation.
  • This is nothing more than the original scenario continued beyond the minimum level off height to the point where the operating engine reaches its ten minute limit. The height is measured 35' (dry runway) / 15' (wet runway) above the runway, "reference zero."

  • 3R — The maximum Level-Off altitude (altimeter indicated) is displayed here.
  • Once again this is the same point in space, adjusted for the elevation of the departure end of the runway and corrected for non-standard ISA temperature. In the example there is no obstacle, the departure end of the runway is at 124', and the temperature is 2°C which results in a temperature correction for 5,000' of 220'. (So 5,024 + 124 + 220 = 5,368')

    More about: Altimeter Temperature Correction.

  • 4L — The average gross gradient from reference zero is displayed here.
  • The aircraft flies an even shallower arc and in the example the average of that arc comes to 5.1%.

  • 4R — The maximum SID gross gradient from DER is displayed here.
  • The performance computer draws a line from the departure end of the runway to the point in space where the engines reach their 10 minute limit.

  • 5L — From reference zero, note - an * indicates that the data is computed from the Reference Zero position on the runway.
  • 5R — From DER, note -- ** indicates that the data is computed from the departure end of the runway (DER).
  • 6L — T.O. INIT prompt.
  • 6R — CLIMB prompt.
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Figure: Max Level Off Example, from Eddie's notes.

In our example, the aircraft arrives at then ten-minute point when at 5,024' AGL (LSK 1L) via a curved arc as the single engine performance tapers off a bit with altitude. The average gradient of that arc comes to 5.1% (LSK 2L). The performance computer tells us that this point in space will be at 5,368' indicated altitude (LSK 1R), based on the departure end of the runway's elevation and the temperature correction off ISA. It is the exact same point in space. The performance computer draws a line from the departure end of the runway to this point and tell us it comes to 312 ft/nm (LSK 2R), which factors to a gradient of 5.1%. It makes sense that this would be close to the average gradient. The further away you get from takeoff, the less significant the distance between reference zero and the departure end of the runway to become.

Takeoff Place / Bearing / Distance

If I don't have a specific departure procedure to fly, I like to give the FMS a target two miles on runway heading. It gives me yet another reference for where straight is, should I need one in the event of an engine failure. I had been in the habit of simply selecting the runway line from the FMS page and adding a 2 for two miles. Turns out that wasn't right.

Place/Bearing/Distance Placement Using a Runway

[Honeywell Direct-To, Mar 2014]

  • Using the Place/Bearing/Distance (PBD) method is a simple way for flight crews to insert a pilot-defined waypoint at a bearing and distance from another waypoint in the navigation database. For example, if a pilot wanted to put in a waypoint 30NM from PXR at the 064 degree bearing, they would enter PXR/064/30.
  • Things get a bit more difficult when using a runway to define a PBD waypoint. Honeywell has discovered that many operators believe that the FMS will use the departure end of the runway as the beginning point, which is not correct. Instead, the FMS will use the runway approach end threshold as the anchor point for the PBD. In the example shown in Figures 1 and 2, a waypoint is added to a flight plan that does not contain a Standard Instrument Departure procedure (SID). This example could be used to comply with an ATC request or to meet certain departure criteria, including noise abatement procedures.
  • In this example, the flight crew has been instructed to maintain the runway heading for 2NM beyond the departure end of the runway. The crew has used the PBD method to insert a waypoint (*PBD03) using 2NM ( KDVT.RW07R/074/2). This has resulted in a waypoint that is 2NM from the runway approach end threshold, but only .8 NM from the departure end of the runway, which is 8197' in length.
  • The takeaway here is that flight crews will need to add the length of the runway to the distance, or use a different waypoint (VOR/NDB/named waypoint/departure end of runway) as the anchor point of the PBD. Otherwise, the PBD waypoint could be a mile or more away from where the crew and ATC expect it to be.

True/Magnetic Selection

The airplane knows when it needs to use true heading instead of magnetic heading and will make the switch for you. There is a procedure to allow you to make the change manually, shown below. There are a lot more things to consider when this happens.

See: High Latitude Operations

Limitations

[G450 Airplane Flight Manual, §1-03-10, ¶6.]

  • TRUE heading must be selected prior to N73° and S60° Latitude.
  • Operation must be conducted in accordance with the guidance and limitations expressed in Section 01-34-30, Flight Management System (FMS).

[G450 Airplane Flight Manual, §1-34-10] Honeywell HG2100AB and HG2100BB Series IRS equipment installed in the Gulfstream G450 has been certified for alignment to 78° Latitudes. For alignment between 70° and 78° Latitude, fifteen (15) minute alignment time is required. For flight above 73° N and 60° S Latitude, EFIS heading information must be switched from magnetic (MAG) to TRUE due to loss of valid MAG heading from the IRS.

True/Magnetic Automatic Selection

[G450 Aircraft Operating Manual, §03-08-310]

  • When flying above the latitude for a valid mag heading, the FMS automatically switches to true heading. The MCDU scratch pad message ACTIVE MODE IS TRUE HDG is provided.
  • When flying below the latitude for a valid mag heading, the FMS automatically switches back to mag heading (if mag heading is selected on the MAINTENANCE 3/3 MCDU page). The MCDU scratch pad message ACTIVE MODE IS MAG HDG is provided.

True/Magnetic Pilot Selection

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[G450 Aircraft Operating Manual, §2B-27-150 ¶4]

  • If TRUE is the active mode, all courses and headings displayed by the FMS are followed by the letter T. If MAG is the active mode, all courses and headings displayed by the FMS are followed by a degree symbol (°) on the FMS pages.
  • The active mode also reflects how courses are displayed on the HSI. If the FMS is selected as the navigation source for the HSI, the course displayed by the FMS is relative to the mode that is displayed for the ACTIVE HDG MODE on this page.
  • The pilot can toggle between magnetic and true by pushing the line select key at 2R.

High Latitude Flying

[G450 Aircraft Operating Manual, §2B-27-150 ¶5]

  • Entering the polar region (above 89° N or below 89° S) results in the message ENTERING POLAR REGION being displayed. When entering the polar region, the FMS uses its highest priority sensor for navigation. Sensor blending is suspended and the FMS position is slowly ramped to the position of its highest priority sensor. Under normal circumstances, this means that FMS 1 uses IRS 1, FMS 2 uses IRS 2 and FMS 3 uses IRS 3. If the highest priority sensor has failed, the next priority sensor is used. The POS SENSORS page indicates which sensor is being used.
  • Under normal operations, the onside IRS is used as the heading source by EFIS (IRS 1 for the pilot and IRS 2 for the copilot). If the EFIS and FMS are using the same IRS, the EFIS will display a 180° reversal at the same time the FMS crosses the pole.
  • When leaving the region (below 88° N or above 88° S), the message EXITING POLAR REGION is displayed. The FMS resumes sensor blending and slowly ramps from the high priority sensor position to the blended sensor position.
  • The plan mode for the EFIS map display is not useful while at or near the pole. The information presented is correct, but the presentation is not useful because the plan mode is presented North up. When at the North pole for example, everything is South. Therefore, the plan mode must not be used during operations at or near either pole. Instead, use the regular map mode.
  • Correctly flown holding patterns are possible while in the polar region. However, the EFIS airplane symbol does not always show on the holding pattern. The display error is more pronounced the further away the aircraft is from the holding fix and/or the closer the aircraft is to the pole. If a holding pattern is hand flown in the polar region, the HSI presentation should be used for required track and deviation.
  • Since the FMS uses the highest priority IRS (GPS if no IRS is available) and the IRS position cannot be updated, manual FMS position update is not permitted in the polar region.
  • During operations in the polar region, FMS lateral offset is inhibited. Any entered lateral offset is removed when entering the polar region.

Update Winds

If you don't have accurate winds in your flight plan, you don't really have an accurate flight plan. There isn't much about how to do this in the manual and the fact there are two methods makes it even more confusing. You may need both methods, though one is arguably better than the other. (Especially if you are crossing an ocean and the winds are critical.)

Down linked Flight Plan Matched Winds

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Photo: PERF Index, from Eddie's aircraft.

The operating manual is silent on how do to this, but it does point you in the right direction. To access the flight plan winds, press the PERF key and from that menu select PERF PLAN (LSK 2L)

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Photo: MCDU PERF Plan, from Eddie's aircraft.

[G450 Aircraft Operating Manual, §2B-26-50] The PERF PLAN pages display the estimated fuel remaining and ETE for each leg of the flight, as shown in [the figure]. No flight plan changes can be made from this page. The PREV and NEXT keys are used to review the entire flight plan. In addition to this information, this page shows a wind/temperature (W/T) prompt (right line select) for each waypoint.

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Photo: MCDU Wind/Temp page, from Eddie's aircraft.

The operating manual shows that each value can be changed manually but does not show the DLK WINDS prompt. So, from experience, here is how you do this:

  • Select DLK WINDS (LSK 6L)
  • Select ACCEPT (LSK 6R)
  • Select WINDS (LSK 6L)
  • Review winds for each leg by pressing NEXT and PREV

It has been our experience that this will insert the winds that came loaded with the flight plan. This means the winds are already in memory so the "DLK" happens rather quickly. The biggest advantage of this method is the numbers in the FMS will agree with the numbers on your flight plan. Downside? The winds can be very old, depending on when the flight plan itself was originated.

Down Link Updated Winds

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Photo: NAV Index, from Eddie's aircraft.

You can get current winds, at least the most current winds available, by data link. Press the NAV key and then select DATALINK (LSK 2R)

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Figure: Data link index, from G450 Aircraft Operating Manual, §2B-21-00, figure 9.

Select WINDS REQ (LSK 2R)

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Figure: Data link winds request, from G450 Aircraft Operating Manual, §2B-21-00, figure 10.

Select YES (LSR 1L)

Select SEND REQST (LSK 6R)

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Figure: Data link winds review, from Eddie's aircraft.

When prompted that the winds have arrived, select WINDS REQ (LSK 2R)

The manual isn't clear on what this procedure does versus the earlier PERF PLAN procedure but it has been our experience that these winds will be more accurate if it has been a while since the original flight plan was computed.

VNAV Offset

There are several ways to insert a VNAV offset point, the quickest is with the MCDU so I'll cover that here. Why is speed important here? Because you lose valuable style points with delay. The PF might need the altitude select knob set quickly if an aggressive descent is needed, and the PM needs to program the FMS quickly to make the severity of the required descent clear. Of course the PF could be doing the math at the same time just to make sure the box was programmed correctly. How?

See: 60 to 1, Technical / 60 to 1: Engineer to Pilot Translation, and That Looks About Right (TLAR).

Procedure

[G450 Aircraft Operating Manual, §2B-28-30, ¶3.] ATC often issues a clearance that consists of crossing a specified distance before or after a waypoint, at a specific altitude. The FMS is capable of creating a temporary waypoint in the form of a *PDXX for these types of clearances.

  • Define a PLACE. Use the keyboard or line select the place from the flight plan to the scratch pad.
  • Enter a slash (/) to indicate that the next entry is a bearing. If known, enter the bearing. When the bearing is unknown, enter another slash (/) to indicate that the next entry is a distance.
  • Enter the distance to cross from the place. If DRK is the place, the entry is DRK//20.
  • Enter this information into the flight plan either at or after the place (DRK). The FMS automatically places the waypoint on the flight plan at the specified distance.
  • Enter the altitude constraint.

Procedure (with a little) Technique

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Photo: Flight Plan Example Before VNAV Offset, from Eddies aircraft.

Let's say you are at 43,000' flying south to Charleston with the active flight plan showing in your MCDU.

Jacksonville Center instructs you to descend to FL210 100NM north of Snow Hill.

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Photo: Flight Plan Example With Scratch Pad Entry Started, from Eddies aircraft.

You need to keep the distance and altitude in mind when you hear the fix location. Identify the fix on the MCDU, in our example SWL. Press the corresponding left line select key, LSK 2L in the example.

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Photo: Flight Plan Example With Scratch Pad Entry Completed, from Eddies notes.

Enter two slashes, the distance, another slash, and the altitude. In our example: SWL//100/21000.

The two slashes are necessary to differentiate a place/bearing. SWL/100/10, for example, would mean to insert a point on the 100° radial at 10 DME.

Enter this scratch pad line into the flight plan by pressing the line select key at the point which is to follow, LSK 2L in our example.

At this point make the altitude change on the guidance panel so the PF can begin descent if so desired.

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Photo: Flight Plan Example VNAV Offset Confirmation Page, from Eddies notes.

If the new leg will change your next "to" waypoint, you will get a confirmation query page. Select Yes (LSK 6R) if this is your intention.

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Figure: Flight Plan Example With Descent Entered, from Eddies notes.

The point is entered and the data is updated. In our example we still have some time so the FMS has computed a 3.0 degree descent for us. Selecting the VNAV key on the guidance panel will allow us to intercept this VPATH.

Another Technique

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Photo: Flight Plan Example on Map Display Before VNAV Offset, from Eddies aircraft.

You can do the same thing without the MCDU. Here you are in the same situation.

Jacksonville Center instructs you to descend to FL210 100NM north of Snow Hill.

Another Technique

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Photo: Flight Plan Example on Map Display with VNAV Offset Dialog, from Eddies aircraft.

You can click on the fix in question and select "Cross" from the pop up menu.

The net effect is the same as with the MCDU but it takes quite a bit longer since the altitudes and distances have to be scrolled.

VOR Tuning

This does not appear in any G450 manual but the system works almost the same way in the GV, so the source material is the GV Operating Manual.

[GV Aircraft Operating Manual, §2B-05-50, ¶12.A]

  • The small letter in front of the navaid identifier in the lower part of the RADIO TUNING and PROGRESS pages indicate the tuning mode for the NAV radios (VOR and DME). The tuning modes are as follows:
    • A (auto tune)
    • V (NAV displayed as nav source, auto tune suspended)
    • R (remote tune)
    • M (manual tune)

The G450 manuals do not contain this explanation, but all four modes exist in the G450.

Auto Tune Mode

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Photo: MCDU Progress Page, Nav Tune Mode "A", from Eddie's aircraft.

[GV Aircraft Operating Manual, §2B-05-50, ¶12.A]

  • AUTOTUNE — The tuning mode is autotune when the FMS is tuning the VOR.
    • In autotuning, the FMS automatically selects a navaid, tunes it, and checks the data from the navaid. No pilot interaction is required.
    • During autotuning, the FMS tunes the VOR that the pilot would most likely tune whenever possible. If the VOR is required for navigation, the FMS tunes the VOR so the most optimum VOR/DME position can be established.
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Photo: MCDU Nav1 Page FMS Tune On, from Eddie's aircraft.

If you want AUTOTUNE, make sure the FMS TUNE setting on the NAV page is ON, the navigation source is LRN, and there is no course previewed — no green needles — and press the DELETE key and then the appropriate line select key, LSK 5L or LSK 5R.

VOR Tune Mode

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Photo: MCDU Progress Page, Nav 1 Tune Mode "V", from Eddie's aircraft.

  • VOR TUNING
    • If autotuning is active when NAV is selected as the navigation source on EFIS, the letter V is displayed adjacent to the navaid identifier. The V indicates that autotuning is selected but is suspended while NAV is displayed. If EFIS is switched back to FMS, autotuning resumes. Remote tuning by the pilot is possible while V is displayed. If this is done, the tuning mode changes to remote (R).
    • If NAV has been selected with the EFIS preview display feature, autotuning is disabled.

If you see a "V" here, that means you were in "A" but then selected the VOR/ILS receiver as your navigation source or previewed the VOR/ILS.

VOR Remote Tune Mode

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Photo: MCDU Progress Page, Nav 1 Tune Mode "R", from Eddie's aircraft.

  • REMOTE TUNING
    • The tuning mode is remote if the pilot has tuned the NAV radios through the FMS or from the radio control head. The FMS does not change the frequency the pilot has selected.
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Photo: Map Display, Tune Nav 1, from Eddie's aircraft.

Of course the G450 does not have a radio control head, so "R" means this was done through the Map Display.

VOR Manual Tune Mode

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Photo: MCDU Progress Page, Nav 1 Tune Mode "M", from Eddie's aircraft.

  • MANUAL TUNING
    • If the manual tuning mode is active, the FMS cannot tune the VOR or associated DME channel. Tuning can be done only by the pilot through the radio control head. Manual tuning is activated by a menu selection on the radio management unit (RMU). The FMS still tunes the blind channels of the scanning DME during this mode.
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Photo: MCDU Nav1 Page FMS Tune Off, from Eddie's aircraft.

While the G450 does not have a radio control head, it is still possible to get "M" displayed for manual tuning by turning the NAV page "FMS AUTOTUNE" to off. It isn't clear why you would ever want to do this.

References

Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.

Gulfstream Flight Management System Quick Task List (FMS QTL), Rev 1, Aug 20, 2012

Honeywell Direct-To Newsletter, 2012 Q4

Honeywell Direct-To Newsletter, Sep 2009

Honeywell Direct-To Newsletter, Mar 2014

Honeywell Direct-To Newsletter, May 2015

SATCOM-Direct AGCS Memo.

Revision: 20170401
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