The US Marine Corps estimates it will take another seven months to restore all of its Boeing/BAE Systems AV-8B Harrier II aircraft to flying status.
Most of the fleet, powered by the uprated Rolls-Royce F404-408, has been grounded since July following the loss of an AV-8B. It is suspected that the crash resulted from a No 3 engine-bearing failure.
One of two possible failure causes is improper bearing installation. A new handling process has been developed for the bearing, which is a blind fit, applicable to new build and overhauled engines.
Recently built F404s using the new process are unaffected, providing 33 operational engines. "We still have 164 engines that need to be done and that has impacted 70- plus aircraft. Right now the repair rate is 10 per month," says USMC AV-8B manager Col Tom White.
The engines are now being vibration tested to check for out-of-balance conditions. As a result, 22 of the 45 AV-8Bs recently returned to service have been re-grounded.
Source: Flight International
