Transforming your craft from an oceanic vessel back to domestic operations is just a matter of making the right contacts, finishing some paperwork, removing SLOP (if any), and getting the cockpit ready for airways, radar contact, and full time air traffic control.
This section continues an example G450 trip from Bedford, Massachusetts (KBED) to Geneva, Switzerland (LSGG), to Mumbai, India (VABB), to Tokyo, Japan (RJAA), to Honolulu, Hawaii (PHNL), to San Francisco, California (KSFO), back to Bedford. For the purpose of covering an oceanic departure, this section will focus on the KBED to LSGG leg. To view the steps required prior to oceanic airspace entry, see: Oceanic Departure. For the en route portion, see: Oceanic En Route.
Everything here is from the references shown below, with a few comments in an alternate color.
Figure: Example Plotting Chart (Arrival), from Eddie's notes.
Figure: RVSM/Nav Accuracy Log, Coast In, from Eddie's notes.
[AC 91-70B, ¶D.2.11.3] Compare LRNS to ground-based NAVAID (as applicable depending on your equipage). 1. When departing oceanic airspace and acquiring ground-based NAVAIDs, you should note the accuracy of your LRNS compared to the position information provided by those NAVAIDs. 2. You should note discrepancies in your maintenance log.
The coast-in navigation accuracy check is conducted in the same manner as for coast-out, except that the earliest possible navigation aid is sought for the first opportunity to check navigation performance, keeping in mind the service volume of the navaid is limited.
More about this: Navigation Accuracy Check.
[AC 91-70B, ¶D.2.11.1] Remove strategic lateral offset. You must remove the strategic lateral offset prior to exiting oceanic airspace at coast-in. We recommend you include this as a checklist item.
[AC 91-70B, ¶D.2.11.2] Confirm routing beyond oceanic airspace. Before entering the domestic route structure, you must confirm your routing and speed assignment.
Figure: Transition Layer Descent, from Eddie's notes.
[AC 91-70B, ¶D.2.12.1] Transition Level. During the approach briefing, you should note the transition level on the approach plate or verify with ATC. You must reset your altimeters to QNH when descending through the transition level. You should confirm whether the altimeter setting is based on inches of mercury or hectopascals.
[ICAO Document 4444, Ch 1]
G450 Note: The FMS transition level function can be useful because it will alert you 1,000 feet after passing the transition layer.
More about this: Transition Altitude/Layer/Level.
See: Record Keeping, below.
The most crowded airspace in the world must be in Europe, because the charts are crammed full of airways and fixes. This mess is a carryover from the bad old days when every country had its own border crossing rules and there were border fixes on every border. These days you are very likely to get cleared direct to the opposite border exit point or even further, but you still have to file all those points. If the controller gets busy or is on strike — happens more than you think — you will have to know where those airways are and each of the waypoints too. It really pays to identify all those airways and fixes before your takeoff or coast in:
Photo: European Chart With Highlighter Marks, from Eddie's collection
But what happens on your next trip, and the trip after that. Pretty soon you have too many yellow lines to identify the correct line. There are several techniques out there to fight this:
Photo: European Chart With "Post It" Notes, from Eddie's collection
Figure: RVSM/Nav Performance Log, Final, from Eddie's notes.
[AC 91-70B, ¶D.2.13.1] When arriving at your destination gate, you should note any drift or circular error in your LRNS. 1. A GPS primary means system normally should not exceed 0.27 NM for the flight. 2. Some inertial systems may drift as much as 2 NM per hour.
[AC 91-70B, ¶D.2.14] You must note problems in the altimetry system, altitude alert, or altitude hold in the maintenance log.
There doesn't appear to be any written guidance on keeping records of your oceanic flights any more, now that AC 91-70A has been replaced and the newer AC 91-70B doesn't mention record keeping at all. Here is the old guidance:
[AC 91-70A, ¶3-6.t.] At the end of each flight, determine the accuracy of the navigational system to facilitate correction of performance. You may perform a check to determine the radial error at the ramp position as soon as the aircraft parks. Radial errors for INSs in excess of 2 NM per hour are generally considered excessive (part 121, appendix G). Keep records on each individual navigation system performance.
[AC 91-70A, ¶3-12.c.]
There is some guidance in ICAO NAT Doc 007:
[ICAO NAT Doc 007, ¶11.2.1] Decisions regarding the monitoring of aircraft navigation performance are largely the prerogative of individual operators. In deciding what records should be kept, operators should take into account the stringent requirements associated with the NAT HLA. Operators are required to investigate all lateral deviations of 10 NM or greater, and it is imperative, whether these are observed on ground radar, via ADS reports or by the flight crew, that the cause(s) of track deviations be established and eliminated. Therefore, it will be necessary to keep complete in-flight records so that an analysis can be carried-out.
It may be useful to carry an envelope for each planned oceanic leg, labeled with the following information:
The following items, as applicable, should be retained at the aircraft base:
There is no regulatory guidance on how long these records should be retained. We use six months.
*Advisory Circular 91-70A, Oceanic and International Operations, 8/12/10, U.S. Department of Transportation
* This version of AC 91-70 has been superseded but it retained because it contains older guidance that helps place current guidance into perspective.
Advisory Circular 91-70B, Oceanic and International Operations, 10/4/16, U.S. Department of Transportation
ICAO Annex 10 - Vol V, International Standards and Recommended Practices, Annex 10 to the Convention on International Civil Aviation, Vol V, July 2001
ICAO Doc 4444 - Air Traffic Management, 16th Edition, Procedures for Air Navigation Services, International Civil Aviation Organization, October 2016
NAT Doc 001, Guidance and Information Material Concerning Air Navigation in the North Atlantic Region, Seventh Edition, January 2002.
ICAO Doc 7030, Amendment 1, International Civil Aviation Organization, 8 January 2009
ICAO Nat Doc 007, North Atlantic Operations and Airspace Manual, v. 2019-2, applicable from 28 March 2019
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