Action
Final rule; request for comments.
Summary
We are superseding emergency airworthiness directive (AD) 2014-12-52 for all Honeywell International Inc. TFE731-4, -4R, -5AR, - 5BR, -5R, -20R, -20AR, -20BR, -40, -40AR, -40R, -40BR, -50R, and -60 turbofan engines. Emergency AD 2014-12-52 was sent previously to all known U.S. owners and operators of these engines. AD 2014-12-52 required, before further flight, a review of the engine logbook maintenance records to determine if any affected engines are installed. AD 2014-12-52 also prohibited operation of an airplane with two or more affected engines that have 2nd stage low-pressure turbine (LPT2) blades with less than 250 operating hours since new. This AD retains the requirements of AD 2014-12-52 and clarifies the intent of the mandatory requirements. This AD was prompted by reports of LPT2 blade separations. We are issuing this AD to prevent LPT2 blade failure, multiple engine in-flight shutdowns, and damage to the airplane.