A new Airworthiness Directive (AD) has been issued (for an old Mandatory Service Bulletin) to include 161 engines not included in a rule concerning the replacement of crankshaft retaining bolts on Lycoming 540-series engines. The latest rule takes effect at the end of the month, with no notice period, because of the serious nature of the problem. However, it comes about six months after Lycoming issued a Service Bulletin listing the affected engines. The original AD was issued in November 2002 after zinc-coated crankshaft retaining bolts failed in two 540-series engines. Cadmium-coated bolts replace the zinc-coated bolts. The AD also approves five kits, developed by Lycoming, to conduct repairs on the affected engines. A spokesman for Lycoming said the recall of the 161 engines is nothing new, but rather the FAA’s catching up to the Service Bulletin already issued by Lycoming.
More Engines Included In Crankshaft Bolt AD
Key Takeaways:
- A new FAA Airworthiness Directive (AD) mandates the replacement of zinc-coated crankshaft retaining bolts with cadmium-coated bolts on an additional 161 Lycoming 540-series engines.
- The AD, which takes effect at the end of the month without a notice period due to the serious safety nature, addresses a problem that led to engine failures and builds upon an original 2002 AD.
- Lycoming had already issued a Service Bulletin six months prior regarding the affected engines and developed five approved kits for the required repairs, with the FAA now formalizing the process.
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