U.S. regulator demands fix for Boeing 747-8 to avoid crash

The Federal Aviation Administration's so-called airworthiness directive covers Boeing's 747-8 and 747-8F planes with certain General Electric Co engines, and calls for removing defective software and installing new, improved software.

The rule directly affects seven airplanes in the United States, the FAA said, but if adopted internationally it would affect a larger number. Boeing's website said it has delivered 66 of the four-engine jets to customers since the model was introduced in October 2011.

The issue never caused a problem in flight, Boeing said, and marks the fourth such directive affecting the 747-8.

Because of the seriousness of the safety issues raised, the directive takes effect April 9, waiving a usual comment period, though comments can still be submitted, the FAA said.

Boeing said data analysis indicated a potential problem and it advised customers last year to update the software. It said it believed the majority of operators had already done so.

The risk of failure was "extremely remote," Boeing said.

GE said it owns the software and jointly analyzed it with Boeing, but Boeing made the decision 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 FAA 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. China's Cathay Pacific <0193.HK> has 13 freighters and Cargolux, based in Luxembourg, has nine.

Korean Airlines Co <003490.KS>, Nippon Cargo Airlines Co Ltd

and Volga-Dnepr UK Ltd also own 787-8F freighters, according to Boeing's website.

(Reporting by Ros Krasny and Alwyn Scott; Editing by Susan Heavey and Tom Brown)