McDONNELL DOUGLAS (MDC) has started testing the durability of the C-17 transport to cover a third equivalent lifetime, or up to 90,000 representative flight hours. The work is part of a $15.7 million contract from the US Air Force.

The additional tests will be conducted on the original durability airframe at Long Beach, California, which finished two lifetimes' testing in November 1994. The new tests are scheduled to continue through to November 1996. The first two 30,000h test phases were completed as part of the initial development contract, but the recent decision to extend production to 120 aircraft has spurred USAF interest in the aircraft's longevity.

"This testing will extend the life of the C-17 in service," says MDC transport-aircraft senior manager of structural testing, Steve Knauf. "In addition, it will give the Air Force information on how to plan for future inspection programmes, identifying specific areas and times to inspect as well as allowing development of maintenance procedures," he says.

The testing of the airframe, which is subjected to the stresses of 24 different flight profiles by 258 hydraulic actuators, will be stopped every 3,000h for inspection.

Source: Flight International