The Royal Australian Air Force has discovered cracking in the engines of its 35 General Dynamics F-111s. The damage was found around tie-bolt holes in the compressor of an F-111C retrofitted with Pratt and Whitney TF30-P109RA engines, and an F-111G fitted with TF30-P107s.
According to the RAAF, the problems, detected during routine inspections, have not been found before on the F-111. The cracks were on different tie-bolt stations.
The RAAF grounded the fleet as a safety measure while inspections were launched to determine the number of affected aircraft. "This problem is in an area never considered prone to fatigue cracking by Pratt & Whitney," it says.
The service says initial inspections failed to find similar problems on other aircraft. The Australian Defence Science and Technology Organisation is expected to perform a metallurgical analysis of the affected components. The USAF is also being consulted because of its F-111 technical expertise.
The RAAF says the problem has never been encountered on the 18,500lb (82kN) TF30-P103 originally fitted to Australian F-111Cs. The service is retrofitting its F-111Cs with the 20,840lb TF30P-109 under a multiyear programme started in 1997.
In April, Australia advised the USA of its intention to acquire up to 130 ex-USAF TF30-P109 engines under the Foreign Military Sales programme.
Source: Flight International