Graham Warwick/WASHINGTON DC
Two airlines have started work to return to service two Boeing 747 freighters grounded in mid-1996, when the US Federal Aviation Administration imposed load restrictions on the GATX Airlog cargo conversion.
Airlog says that work to recertificate the conversion is "about 80% complete" and hopes to release the remaining service bulletins "in another two months".
The FAA issued an airworthiness directive (AD) in July 1996 imposing the limits, citing concerns that structural-load assumptions used in design of the Airlog cargo-door installation were inadequately validated. Ten 747-100/200s were affected. Two, operated by American International Airways and Evergreen International Airlines, are already being reworked, using Airlog bulletins.
Airlog president Rick Hatton says that the engineering required to strengthen and recertificate the cargo door has cost more than $5 million, and come close to exhausting the company's resources. Airlog plans to provide the service bulletins free of charge, he says, but hopes that operators will pay for materials. Hatton plans to sell at least one more 747 conversion to cover Airlog's remaining costs.
Hatton believes that Airlog's experience has "big implications" for firms tackling the FAA's recent ADs on Boeing 727 conversions, as Airlog is the first to go through the redesign effort required for re-issue of a supplemental type-certificate. The FAA is cracking down on third-party conversions designed without access to the original manufacturer's structural-loads data, with McDonnell Douglas DC-8 freighters possibly next.
Source: Flight International
