Airworthiness Directive 2011-31794
one-timeAirworthiness Directives; Continental Motors, Inc. (CMI) Reciprocating Engines
What this AD requires
We are adopting a new airworthiness directive (AD) for certain Continental Motors, Inc. (CMI) models TSIO-520, TSIO-550-K, TSIOF-550K, and IO-550-N series reciprocating engines. This emergency AD was sent previously to all known U.S. owners and operators of these engines. This AD requires replacing affected CMI starter adapters with starter adapters eligible for installation. This AD was prompted by 5 reports received of fractures in starter adapter shaft gears in certain part number (P/N) CMI starter adapters. We are issuing this AD to prevent failure of the starter adapter gear shaft, leading to an inoperable oil scavenge pump and engine in-flight shutdown.
Which aircraft AD 2011-31794 applies to
Emergency AD. Applies to listed engines (IO-550-N limited to Turbo-normalized engines under STC SE10589SC) with one of the listed starter adapter part numbers installed, where the engine was manufactured between January 1, 2011 and November 20, 2011, or a replacement starter adapter purchased from Continental Motors was installed in that window.
Whether AD 2011-31794 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.