Airworthiness Directive · Amendment 39-8798 · Honeywell International Inc. Engines
Honeywell International Inc. Engines
This AD applies to Honeywell International Inc. T5508D.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment adopts a new airworthiness directive (AD) that is applicable to Textron Lycoming Model T5508D turboshaft engines. This action requires a cyclic life reduction for the T5508D impeller, a more conservative method for determining low cycle fatigue (LCF) damage to the impeller, and a method for prorating past impeller usage, based on the new LCF counting factors. This amendment is prompted by a report of a rotorcraft accident found to have been caused by an uncontained impeller failure. A subsequent field campaign inspection of high-time impellers utilized by heavy lift operators confirmed 12 more impellers with similar distress. The actions specified in this AD are intended to prevent an impeller failure, which can result in an uncontained engine failure, inflight shutdown, or possible rotorcraft damage.
