Boeing has advised GEnx engine operators that it is revising the 787’s and the 747-8’s flight manuals to prohibit flight within 50 nm of thunderstorms that may contain ice crystals. Following Boeing’s recommendation, Japan Airlines immediately announced it would switch aircraft on two routes. From April to November, GEnx-powered aircraft suffered six engine-icing events, according to a GE statement. All aircraft landed at their planned destinations, said the engine maker, and none of the incidents involved in-flight shutdowns–only temporary thrust losses.
UK-based low-cost carrier EasyJet, Airbus and Nicarnica Aviation plan a final test in August of the Nicarnica-developed airborne-volcanic-object imaging detector in a bid to prevent major air traffic disruption like the one the eruption of Iceland’s Eyjafjallajökull caused in 2010.
Many cockpit crewmembers believe the ingestion of ice crystals by a jet engine is essentially harmless if the engine’s igniters are turned on. However, aeronautical engineers generally do not agree, citing incidents when mixing ice with standard intake air resulted in a noticeable reduction in engine power output and, at its worst, a complete engine flameout. Ice formation inside an engine compartment can also lead to indicator anomalies that may not shut down the engine, but may lead to air data system failures.
Why some engines fail in flight is the subject of a new NASA research program. “There is a question regarding the effect that moisture has on newer-technology engines.
The FAA’s Draft Advisory Circular 20-147A released last month provides new guidance to aircraft manufacturers on compliance with regulations covering engine induction system icing and engine installation ice requirements. Comments on the draft AC are due by November 1.
The air transport industry was caught off guard in April when huge plumes of ash from Iceland’s Eyjafjallajökull volcano effectively shut down flying in Europe for a week, stranding thousands of passengers and draining at least $1 billion from air carriers.
The FAA and Pratt & Whitney Canada believe they have found the cause of at least three high-
altitude, dual-engine flameouts on Pratt & Whitney Canada JT15D-5-powered airplanes operating in certain meteorological conditions. In a proposed Airworthiness
The FAA and Pratt & Whitney Canada believe they have found the cause of three high-altitude double engine flameouts on Pratt & Whitney Canada JT15D-5-powered Beechjets between mid-2004 and mid-2006.
Hawker Beechcraft Beechjet 400, Jacksonville, Fla., Nov. 28, 2005–Both engines of the Flight Options Beechjet flamed out because high-altitude ice crystals that had accumulated on the P&WC JT15D-5 engines’ compressor vanes were ingested when the pilots pulled back the power levers to descend, according to the NTSB.
Hawker Beechcraft Beechjet 400A, Norfolk, Va., June 14, 2006–The NTSB said the probable cause of the dual engine flameout was the accretion of high-altitude ice crystals on the compressor vanes and their ingestion into the engine high-pressure compressor when the pilots pulled back the power levers. This caused compressor surges and the flameouts of both engines.
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