A source on Wednesday claimed the issue involved engine blades wearing out, with the pause set to be another blow for a training programme to deliver fast jet fighter pilots that has already dealt with a series of issues and delays.
The Royal Air Force has grounded its entire fleet of fast jet training aircraft because of an issue with an engine, Sky News can reveal.
It is not known when flying training on the Hawk T2 jets at an air base in North Wales will resume.
The pause will be another blow for a training programme to deliver fast jet fighter pilots that has already been plagued by problems and chronic delays for years.
Sky News revealed last year that an "emerging" problem had been identified with the Rolls-Royce engine on the Hawk jet, used by fast jet recruits for training at RAF Valley.
A source on Wednesday claimed the issue involved engine blades wearing out.
"Now one has broken and gone down the engine," the source said, asking to remain anonymous.
An RAF spokesperson confirmed that flying on the Hawk 2 jet had been paused "as a precaution".
"Post a recent issue on the runway involving an RAF Hawk TMk2 engine, as a precautionary measure, flying has been temporarily paused pending the results of the technical investigation," the spokesperson said.
It is understood that the RAF is working closely with the manufacturer and awaiting analysis on the specific engine.
Flying training will only resume when it is deemed safe to do so.
The problem with the training fleet will not impact the Red Arrows team, which operates Hawk T1 aircraft.
In an exclusive report last August, Sky News, citing leaked documents, revealed how issues with the Hawk training aircraft and a "damaging drain" of flying instructors quitting for jobs in the industry had helped push the RAF's fast jet pilot training into a new crisis.
RAF recruits can spend up to eight years passing through the training pipeline. The length of time should be only two or three years.
Ben Wallace, the defence secretary, gave Air Chief Marshal Sir Mike Wigston, the head of the RAF, the task of fixing flying training as his only priority more than three years ago.
The Hawk T2 is a single-engine aircraft manufactured by BAE Systems, though the engine is made by Rolls Royce.
Royal Air Force grounds its entire fleet of fast jet training aircraft due to engine problem
A source claimed on Wednesday the issue involved engine blades wearing out, with the pause set to be another blow for a training programme to deliver fast jet fighter pilots that has already dealt with a series of issues and delays.
news.sky.com