Post-emergency Procedures in Oceanic Airspace

By By David Esler david.esler@comcast.net
Source: Business & Commercial Aviation

As the International Business Aviation Council's Peter Ingleton, who directs liaison between IBAC and ICAO, points out, ignorance of oceanic procedures and responsibilities on the part of operators is no excuse.

“There is a wealth of material on the ICAO website,” Ingleton said. “In terms of preparing for the flight, all the material is there — the information is available. After that it becomes a question of professionalism and vigilance.” Nevertheless, tallies of GNEs and LHDs, especially in the NATS, continue to remain fairly constant despite attempts through the years to educate business aviation operators of the criticality of remaining true to the assigned clearance stipulating track heading, flight level and Mach number.

(This is not to say that airline crews or even controllers don't make operational mistakes — the vast majority of which are committed by the airlines, by far the largest users of the track system — but it is generally conceded that especially business aviation operators need to do better, as the stakes for incompetence are so high.) “What you find in both airline and general aviation operations is that the preponderance of errors occurs because the flight crew follows the flight plan instead of the clearance — and that just keeps popping up,” Ingleton said.

Which brings us to our core discussion of oceanic emergency procedures, or in controller-speak, “contingencies.” A contingency is a procedure, and in the oceanic operations context, those with which pilots should be knowledgeable and adept address emergencies, weather diversions, loss of communications and loss of long-range navigation capability. Note that there are general ICAO contingencies and, from those, others that are tailored for and apply only to specific regions and OTSes.

When something happens that is sufficiently serious to warrant a departure from the assigned route or track, the procedure is identical — a fact that not all pilots realize, as an assumption widely exists that the contingency applies only within an OTS. “It makes no difference whether you're on the tracks or not, the contingency procedures are the same,” affirmed Dave Stohr, president of Air Training International, headquartered near Dallas. “The only place where there is a difference is operating above MNPS-RNP airspace in the North Atlantic region and having to descend through it. Other than that, the ICAO procedure is the same in each type of airspace.”

If possible—that is, if the emergency does not require immediate action (e.g., an explosive decompression)—the first task, no matter where you are, is to coordinate with ATC and obtain a revised clearance. “Due to communication or time constraints, you may not be able to do that,” Stohr said. “If you cannot take action with a revised clearance, the flight crew should then turn 45 deg. off the cleared route of flight. Whether left or right is the pilot's decision.” Obviously, if operating on an outside track of an OTS, the turn should be made away from the track system, on a published route, away from the route system.

The crew is then to establish a 15-nm offset from the cleared route of flight, flying parallel to the tracks, either in the same direction of flow or the opposite direction, if it is necessary to turn back and the turn can be made without trespassing on adjacent tracks. As stated in the ICAO oceanic procedures, the aircraft is to be placed on an offset track “where other aircraft are least likely to be.”

“If the aircraft can maintain altitude,” Stohr explained, “when the aircraft is 10 nm off the cleared route of flight, the crew should then climb or descend as able, 500 ft. if at FL 410 and below or 1,000 ft. if operating above FL 410. If the nature of the problem is such that the aircraft cannot maintain altitude, then the pilot should minimize descent to the maximum possible while achieving separation from the cleared route of flight.” Somewhere in this process, if communication is possible, the crew should advise ATC of the aircraft type and nature of the problem.

Crews should also be knowledgeable of the drift-down procedure for their aircraft type and have practiced it in a simulator. “The operating manuals for today's business jets describe drift-down procedures, where you trade altitude for range or distance,” Stohr continued. “This enables the flight crew to minimize descent while clearing traffic for route of flight. You have to take into consideration the aircraft below you.” This includes those that might be flying the Standard Lateral Offset Procedure (SLOP) 1 or 2 nm to the right of their assigned track. While all the traffic is going in the same direction in an OTS, on some random routes, it's bidirectional at odd and even flight levels, another justification for the 45-deg. offset procedure if descending.

Another detail demanding attention is to broadcast on 121.5 or 123.45 MHz the aircraft identification, flight level, position and intentions to alert other aircraft in the vicinity. And based on your calculated equal-time point (ETP) and assigned clearance (not the flight plan), decide early in the flight where you will go if a diversion is necessary. (See “Be Proactive” sidebar for a sample contingency checklist.)

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