DAVID LEARMOUNT / LONDON
But as a radical overhaul of codes governing flight over oceanic or wilderness areas looms, FAA and JAA opinions still differ
New rules governing the operation of twin-engined airliners far from diversion airfields are expected to give pilots greater discretion on continuing or diverting in the event of an engine shutdown.
Boeing believes the US Federal Aviation Administration's imminent notice of proposed rulemaking (NPRM) will reflect closely the recommendations of the Aviation Rulemaking Advisory Committee (ARAC) on extended range twin-engine operations (ETOPS) (Flight International, 31 December 2002-6 January 2003).
Boeing Commercial Airplanes' vice-president regulatory affairs, Capt Chet Ekstrand, says although the NPRM is expected to recommend that the same rules apply for suitably equipped twin-engined aircraft, trijets and quads, he believes the emphasis will be on allowing the pilots of twins the discretion to continue when faced with a single-engined diversion to a "hostile" airfield, "if that is reasonable".
Ekstrand suggests that at present, pilots of twins with an extraordinarily high level of proven reliability are under unreasonable pressure to make one engine inoperative (OEI) diversions when continuing might be the safer option.
When challenged as to whether pilots of a twin and a quad under the same OEI circumstances might judge priorities differently, Ekstrand concedes this is true but adds that it is no reason to remove the option by regulation.
If the principle is adopted in the NPRM - expected to be published in August - it could effectively extend the guidelines on how far a twin may route from the nearest diversion airfield from 180min to 240min.
Meanwhile, the European Joint Aviation Authorities expects to reach the final draft of its ETOPS notice of proposed amendment (NPA) by June and publish it between October and December. It does not agree that twins are equivalent to quads because "diversion strategy depends on systems redundancy", which is greater on quads.
JAA rules would allow pilots of OEI quads the discretion to continue to their destination subject to the status of the aircraft's redundant systems.
Source: Flight International
