﻿ Remote chances - 4/10/2001 - Flight Global

Remote chances

This story is sourced from Flight International
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ETOPS, always a key for heated discussion, has a successor - LROPS - which will generate just as much debate. The former - extended range twin-engine operations regulations - addressed the maximum flying time that a twin-engined airliner should be allowed to operate from a suitable diversion airport, and what minimum equipment all types of aircraft flying a long way from diversions must carry. LROPS (long range operations) is not specifically about the number of engines, but addresses the wider issues created by the many advances in commercial air transport equipment and operations over the last 15 years. These changes include further increases in aircraft long-range performance, continuing actual and potential improvement in aircraft and equipment reliability, and the opening up of airspace over the Arctic and Siberia for potentially extensive use by the airlines.

Whereas the argument used to be about how far from a diversion in, say, the mid-Pacific, a twin-engined aircraft may fly, the issues now are that aircraft will, far more often than they used to, fly over huge areas in which the climate, territory and remoteness are all extreme. The question now is whether diversion in some of these regions is acceptable at all. If not, can standards in aircraft design, equipment and operating procedures be upgraded to the point where the need to divert can be virtually eliminated? For example, if an aircraft were forced to divert because of a non-engine emergency like a cargo hold or cabin fire, the passengers might be forced to carry out an immediate evacuation on landing, using emergency exit slides, in temperatures as low as –40°C with a high wind. They might well not survive that.

It would clearly be better to ensure that freight fires do not happen, but if they do they can be extinguished however severe. The same would apply to an electrical cockpit or cabin fire like that on the Swissair Boeing MD-11 near Nova Scotia in September 1998, where the aircraft became uncontrollable and crashed before it reached its diversion.

Airfields in remote regions were not built with widebody aircraft operations in mind, and some of them - like Longyearbyen in the high arctic Spitzbergen islands - require special pilot training for crews who fly there. Norwegian carrier Braathens flies a Boeing 737 schedule into Longyearbyen, but all crews who operate there have to train in a simulator with a full visual display of the surrounding terrain before they do.

It is not enough to leave this decision to airlines on a trip-by-trip basis, using the normal parameters of forecast weather and current airfield serviceability in areas where weather can change dramatically and fast. It is possible today to improve aircraft equipment and operating standards to the point where diversion is even less likely than it is now, so a new set of higher standards should apply wherever diversion would involve high risk, or where forced landing or ditching would take place in an area so remote that rescue would take a long time if it came at all. While the European Joint Aviation Authorities, prime movers for LROPS, argue that this is an absolute issue, not one of engine numbers, Airbus claims that there are two twin-engined diversions for every one made by a four-engined aircraft, so the well-worn ETOPS arguments have not gone away yet.

If a damaged aircraft lands at a remote airfield, another aircraft will have to land there to evacuate the passengers and crew, and to bring spares, an engineering team, and fresh pilots and cabin crew. So two aircraft are almost inevitably going to be exposed to higher than normal risk for every one diversion.

The JAA argues that today's long-range passengers should not be subjected to any greater diversion risk than those on short-range flights. It is certainly a worthy objective, although it might be held to be unattainable. But just because absolute parity of risk is unattainable, it does not mean that the authorities should not analyse how much closer to the objective they can reasonably require the LROPS operators in the industry to move.