Eddie Sez:

In the Air Force we used to say your career could survive crashing an airplane in flight but crashing an airplane during taxi was fatal. Of course there were exceptions both ways but the point was taken, if anything goes wrong during taxi, the best course of action may be to set the parking brake and set things right.

What follows comes from the references shown below. Where I think it helpful, I've added my own comments in blue.


Taxi

[G450 Airplane Flight Manual §2-04-02]

  1. Transponder . . . AS REQUIRED
  2. Photo: From Eddie's cockpit.

    If the airport requires the transponder on for taxi, you should turn the TCAS to standby to prevent airborne aircraft with older TCAS units from commanding an RA.

  3. EXTERIOR LTS . . . AS REQUIRED
  4. [AC 120-74B ¶7.h.(2)(b)]: Prior to commencing taxi, turn on navigation, position, anti-collision, and logo lights, if available. To signal intent to other pilots, consider turning on the taxi light when the aircraft is moving or intending to move on the ground, and turning it off when stopped, yielding, or as a consideration to other pilots or ground personnel. Strobe lights should not be illuminated during taxi if they will adversely affect the vision of other pilots or ground personnel.

  5. Brake System 1/6 System Page . . . SELECTED
  6. This should be in view of the pilot.

  7. Brakes . . . CHECKED

  8. FLAPS / STAB . . . SET FOR TAKEOFF

  9. TRIM SETTINGS (3) . . . SET

  10. Slip Indicators / Compasses / Flight Instruments . . . CHECKED
  11. Photo: From Eddie's cockpit.

    We've adopted a technique of briefing "around the PFD" starting with the airspeed and working clockwise: "40 knots indicated, V2 bugged, heading, takeoff, takeoff, first altitude is ____, altimeter ____ gives me ____ feet, zero VSI, heading is ____, no flags."

  12. Engine Instruments . . . CHECKED / ALL WHITE

  13. CABIN PRESSURE CONTROL . . . RECHECKED FOR FLIGHT
  14. [G450 Aircraft Operating Manual §2A-21-30.2.B.] With the FLIGHT / LANDING push-button on the cabin pressure control panel selected to LANDING, taxi speed > nine (9) knots, power levers to a position of fifteen degrees (15°) forward or more, and a cabin or baggage door previously opened and closed, the pressurization system will change to FLIGHT.

    If the mode isn't FLIGHT you can simply press the button and make it FLIGHT.

  15. Thrust Reversers (First Flight of Day) . . . CHECK
  16. CAUTION: IF A RAPID “DEPLOY-STOW-DEPLOY” SEQUENCE IS PERFORMED DURING TAXI, A T/R TIMING ISSUE MAY RESULT IN A RED REV ICON DISPLAYED INSIDE THE AFFECTED LP ANALOG INDICATOR (“POINTER GAUGE”) AND THE AFFECTED THRUST REVERSER WILL BE DISPLAYED IN RED ON THE FLIGHT CONTROLS SYNOPTIC PAGE, WITH NO CAS MESSAGES. A RED REV ICON INSIDE THE LP ANALOG INDICATOR WILL REQUIRE THAT THE ENGINE BE SHUT DOWN AND RESTARTED. IF THE CMC HAS THE LATEST LOADABLE DIAGNOSTIC INFORMATION (LDI) UPDATE, THERE WILL ALSO BE A CHECK CMC MESSAGE.

    NOTE: If CHECK CMC message appears, see EICAS Thrust Reverser Red Rev Indication Mitigation Procedure in the G450 Quick Reference Handbook (QRH), Section ND. For aircraft serial numbers 4245 and subsequent and aircraft having ASCs 909, 909A or 910 (or later approved revision) installed, aircraft with LDI part numbers, GIV_426.1_D14_01292011P (cert Delta), GIV_428.0_E10_01292011P (cert Echo), GIV_430.1_F02_01292011P (cert Fox) and later versions, see Option A on page ND-5. Aircraft with LDI part numbers GIV_426.1_D13_09302010P (cert Delta), GIV_428.0_E09_09302010P (cert Echo), GIV_430.1_F01_11152010P (cert Fox), will NOT have a CHECK CMC message and must accomplish Option B on page ND-6 after last use of thrust reversers prior to takeoff.

    If you have the correct ASC or an upgrade LDI and you do not get a "CHECK CMC" message after testing the thrust reversers, Option A on QRH ND-5 says you are good to go.

    If you do not have the correct ASC and an older LDI, you will need to perform the QRH page ND-6 procedure before takeoff. It takes about three minutes to accomplish but has to be done. Where do you find your LDI version? Page 10 of the CMS.

  17. Takeoff Briefing . . . ACCOMPLISHED
  18. [G450 Quick Reference Handbook, pg. ND-3] The takeoff briefing should include the normal call-outs during the acceleration phase to V1 and VR, runway and departure SID, ATC clearance, takeoff configuration, climb performance, and Go/No-Go criteria should also be addressed, including specific duties during an aborted takeoff.

    [G450 Aircraft Operating Manual, §06-02-30 ¶1.] The Takeoff Briefing should always be accomplished during a low stress environment such as on the ramp before aircraft movement. If a runway change occurs during aircraft movement, the aircraft should be stopped when possible and the Takeoff Briefing accomplished with the Parking Brake set. Loading FMS data or accomplishing a Takeoff Briefing while the aircraft is taxiing is not recommended. The Takeoff Briefing has the most variables of any crew briefing. While it is impossible to list every variable, Gulfstream recommends that at a minimum, the following points be discussed by the flight crew before departure: RUNWAY & DEPARTURE SID / ATC CLEARANCE / TAKEOFF CONFIGURATION/CLIMB PERFORMANCE / GO/NO-GO DECISION CRITERIA

    FOR AIRCRAFT 4001-4244 WITHOUT ASC 908B OR ASC 909 (OR LATER APPROVED REVISIONS). TAKEOFFS DURING STRONG CROSSWINDS OR GUSTY CONDITIONS, AIRPLANES EQUIPPED WITH AOA VANES (ASC 055 AND SN 4143 AND SUBS) MAY EXPERIENCE AN AOA MISCOMPARE SITUATION DURING TAKEOFF ROLL. WHEN THIS OCCURS, THE CAS (CREW ALERTING SYSTEM) MAY DISPLAY AOA MISCOMPARE RELATED AMBER (CAUTION) AND CYAN (ADVISORY) MESSAGES AT APPROXIMATELY 60 KCAS. THESE MESSAGES WILL CLEAR AS THE AIRPLANE ACCELERATES PAST 80 KNOTS ON THE WAY TO V1. WITH THIS KNOWLEDGE, FLIGHT CREWS SHOULD BRIEF THIS SITUATION WHEN STRONG CROSSWIND OR GUSTY WIND CONDITIONS ARE PRESENT SO AS TO AVOID UNNECESSARY REJECTED TAKEOFFS KNOWING THAT THE MESSAGES WILL CLEAR AND DO NOT AFFECT SAFETY OF FLIGHT.

  19. HUD Combiner . . . DEPLOY FOR USE / CHECK

  20. Primary and Standby Displays . . . SET FOR DEPARTURE PROCEDURE

  21. Guidance Panel . . . SET
  22. You should have three numbers correctly set, a lateral mode button and the correct PFD CMD button set.

  23. WARN INHIBIT . . . INHIBIT

  24. BLEED AIR Control Panel . . . APU OFF / L & R ENG ON

  25. COWL ANTI-ICE (2) / WING ANTI-ICE (2) . . . AS REQUIRED

  26. Flight Controls Synoptic Page . . . SELECT

  27. Flight Observer Seat Position / Interior Doors . . . CHECK

Minimum Pavement for 180° Turn

Figure: Taxi Width, from G450 Aircraft Operating Manual §2A-06-00 Figure 4.

The "Minimum Taxi Strip for 180 Degree Turn" has been a standard in Gulfstream manuals for decades. In the G-III the diagram told us the wing tip would grow 1.5 feet beyond the nose so we would routinely taxi with 5 feet of objects are make maximum effort turns for minimum space usage. For various Gulfstreams:

  • G-III: nose to inside wheel 44.0 feet, to outside wing 45.5 feet.
  • G-IV: nose to inside wheel 46.5 feet, to tail 48.2 feet.
  • G450: nose to inside wheel 47.4 feet, to tail 48.2 feet.
  • G-550: nose to inside wheel 53.2 feet, to outside wing 56.0 feet.

Why is this important? You will hear most Gulfstream pilots say "the wing grows" in a turn and that is true for the G-III, G-V, and G-550. But in the case of the G-IV and G450 it is the tail that grows. The tail grows less on the G450 because we have a longer nose.


References

Advisory Circular 120-74B, Parts 91, 121, 125, and 135 Flight Crew Procedures During Taxi Operations, 7/30/12, U.S. Department of Transportation

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

Gulfstream G450 Airplane Flight Manual, Revision 36, December 5, 2013

Gulfstream G450 Aircraft Service Change Number 076, Engine Electronic Controller T5.2 Software Upgrade, July 12, 2013

Gulfstream G450 Quick Reference Handbook, GAC-AC-G450-OPS-0003, Revision 34, 18 April 2013