From AVweb
The U.S. Army temporarily grounded its fleet of CH-47 Chinook helicopters on Tuesday citing a small number of engine fires caused by fuel leaks. The Army stated that the cause of the leaks has been identified and corrective measures are being implemented. A statement from Honeywell, the company that manufactures the Chinook’s T-55 engine, attributed the issue to “O-rings not meeting Honeywell design specifications [which] had been installed in some T55 engines during routine and scheduled maintenance at an Army Depot.”“It is believed these suspect O-Rings have been identified and isolated,” a Honeywell spokesperson said. “The U.S. Army and Honeywell were able to validate that none of the questionable O-rings originated or were part of any Honeywell production or Honeywell-overhauled engines. Joint U.S. Army and Honeywell engineers identified the issue and are now working with the Army to provide replacement O-rings on all affected Chinooks.”
It is not known how long the Army’s fleet of around 400 Chinooks will be grounded. It has been reported that around 70 helicopters were being inspected for the faulty part. No deaths or injuries were associated with the engine fires.