FAA requires GE software fault on Boeing 747-8 aircraft to be urgently fixed

In the wake of the MH370 disappearance where an aircraft fault – even if considered unlikely – cannot be ruled out, any safety issue on Boeing aircraft takes on a higher profile. Glitches with the Dreamliner contribute to the a slightly more nervous environment than usual. A software fault with some GE engines which could cause Boeing’s 747-8 aircraft to lose thrust while landing and crash into the ground has to be urgently fixed according to an instruction from the FAA. The new directive reads

[Federal Register Volume 79, Number 57 (Tuesday, March 25, 2014)] [Rules and Regulations] [Pages 16173-16175] From the Federal Register Online via the Government Printing Office [www.gpo.gov] [FR Doc No: 2014-06476]

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model  747-8 and 747-8F series airplanes powered by certain General Electric (GE) engines. This AD requires removing certain defective software and installing new, improved software. This AD was prompted by a determination that the existing electronic engine control (EEC) software logic can prevent  stowage of the thrust reversers (TRs) during certain circumstances, which could cause the TRs to move back to the deployed position. We are issuing this AD to prevent in-flight deployment of one or more TRs due to loss of the TR auto restow function, which could result in inadequate climb performance at an altitude insufficient for recovery, and consequent uncontrolled flight into terrain. 

This AD is effective April 9, 2014.

Reuters Wed Mar 26, 2014 

The U.S. Federal Aviation Administration on Tuesday ordered an immediate fix to the latest version of Boeing Co’s 747-8 plane, saying a software glitch could cause it to lose thrust when close to landing and fly into the ground. The FAA’s so-called airworthiness directive covers Boeing’s 747-8 and 747-8F planes with certain General Electric Co engines. It calls for replacing defective software with a new improved version. The rule, the fourth such directive involving the 747-8, directly affects seven airplanes in the United States, the FAA said. If adopted internationally, the rule would cover a larger number. Boeing’s website said it had delivered 66 of the four-engine jets, the company’s largest, to customers worldwide since the model was introduced in October 2011. …. …. GE said it owned the software and jointly analyzed it with Boeing, but plane maker decided to recommend the software change to customers. According to the FAA, the risk arises when a plane is changing back into “air mode” while performing a “rejected or bounced landing.” That change halts hydraulic pressure used to stow the engine thrust reversers, which slow the plane on landing, the agency said. Without hydraulic pressure, the reversers may not stow fully and might redeploy, which “could result in inadequate climb performance at an altitude insufficient for recovery, and consequent uncontrolled flight into terrain,” the FAA said. Unidentified business jet/VIP customers own the eight passenger models of the aircraft in the United States, according to Boeing’s website. Air cargo company Atlas Air is the largest U.S. commercial owner of the jet, with a fleet of eight 747-8F freighters. Among passenger carriers, Lufthansa is the largest operator, with 11. It said its planes were unaffected by the directive. “GE has confirmed that all our engines already have the software update that is required by the FAA,” a spokesman said on Wednesday. China’s Cathay Pacific has 13 freighters and Cargolux, based in Luxembourg, has nine. Korean Airlines Co, Nippon Cargo Airlines Co Ltd and Volga-Dnepr UK Ltd also own 787-8F freighters, according to Boeing’s website.

In November 2013 another long running software fault on GE engines for Boeing 787’s and 747’s which caused engine flameout in icy conditions seemed to be finally fixed.

FlightGlobal: 10th Nov. 2011 Reports of eight in-flight and four on-ground unintended shutdowns of General Electric CF6-80C2B wide-body turbofan engines have prompted the US Federal Aviation Administration (FAA) to mandate a change out of the engine’s electronic control unit (ECU). A proposed airworthiness directive, to be published on 14 November, will affect 697 CF6 engines flying on US-registered widebody aircraft. The directive supersedes a 2007 AD requiring a software upgrade (8.2.Q1) on the same ECU to increase the engine’s margin to flameout after several incidents where engines had flamed out due to exposure to ice crystals and ice shedding into the engine. With the new software in place, problems continued. FAA said it received two reports of “ice crystal condition flameouts”, which prompted GE to develop another software upgrade (8.2.R) for the ECU. The new software included “improved inclement weather capability, and enhanced fuel metering valve fault handling logic to reduce the risk of [in-flight shut down] caused by intermittent fuel metering valve feedback signals”, said the FAA. Since that time however, there have been 12 additional engine shutdowns, eight in flight and four on the ground, with engines using upgraded ECU software and other upgrades. The problem was found to be caused by ignition system induced noise that created dual-channel faults in the ECU computer.

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