PETALING JAYA: The U.S. Federal Aviation Administration (FAA) had proposed a new airworthiness directive (AD) for Boeing 777s last September which would prevent “loss of structural integrity of the airplane”.
However the AD applied to other B777 models not the B777-200ER which is the model of the missing MH370.
The FAA said the AD had been prompted by a report of cracking in the fuselage skin underneath the satellite communication (SATCOM) antenna adapter.
The FAA said it had also determined that this unsafe condition “is likely to exist or develop in other products of the same type design”.
“We are proposing this AD to detect and correct cracking and corrosion in the fuselage skin, which could lead to rapid decompression and loss of structural integrity of the airplane,” it said in a notice of proposed rulemaking issued last Sept 18.
It added that the AD applied to the B777-200, -200LR, -300, -300ER and -777F series airplanes.
The missing Malaysia Airlines aircraft bearing 239 people onboard is a B777-200ER, and despite massive search and rescue efforts, authorities have yet to locate it after it went off five days ago while en route to Beijing.
In a case baffling aviation experts worldwide, the MH370 flight had abruptly lost all communications with air traffic control at 1.30am Saturday, 40 minutes after taking off from Kuala Lumpur International Airport.
By then, it had already entered cruising mode at 35,000ft (10,670m), which pilots deem the safest portion of the flight.
In the notice, the FAA said one operator had reported a 16-inch crack under the 3-bay SATCOM antenna adapter plate in the crown skin of the fuselage on a 14-year-old airplane with approximately 14,000 total flight cycles.
It said that following this finding, the same operator had inspected 42 other airplanes between six and 16 years old and found “some local corrosion but no other cracking”.
With the proposed AD, operators would have to repair certain conditions either in accordance with an FAA-approved method, using data that meets the certification basis of the airplane or that have been approved by the Boeing Commercial Airplanes Organisation Designation Authorisation (ODA).
It added that it had identified a total of 120 planes in the U.S. registry who would be affected by the AD.