Airlines face a $23 million cost worldwide over a decision by US regulators to prematurely retire a key component on aircraft powered by Pratt & Whitney PW4000-series turbofan engines over cracking concerns.
An airworthiness directive that becomes effective on 24 August 23, 2012 will require the airlines to remove the front hub of the first stage in the high pressure turbine on 954 aircraft worldwide, including 289 on the US registry, the FAA says.
The directive was prompted after a P&W analysis revealed that its original estimate of the service life of the front hubs might be overly optimistic, the FAA says.
If a hub fails due to cracking at full power, the part could burst through the fan case around the engine and damage the aircraft, the FAA says.
The directive follows a notice of proposed rulemaking published on 23 March.