Airworthiness Directive 2010-21-18
one-timeAirworthiness Directives; Cessna Aircraft Company (Cessna) Models 336, 337, 337A (USAF 02B), 337B, M337B (USAF 02A), T337B, 337C, T337C, 337D, T337D, 337E, T337E, 337F, T337F, 337G, T337G, 337H, P337H, T337H, T337H-SP, F337E, FT337E, F337F, FT337F, F337G, FT337GP, F337H, and FT337HP Airplanes
What this AD requires
We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires inspecting the wings for internal and external damage, repairing any damage found, installing an operational limitation placard in the cockpit, adding limitations to the flight manual supplement, and reporting the results of the inspection to the FAA if damage is found. This AD was prompted by a wing overload failure and by reports of cracks in the upper wing skins on certain Cessna airplanes that are or have ever been modified by Aviation Enterprises Supplemental Type Certificate (STC) SA02055AT, SA02056AT, SA02307AT, or SA02308AT. We are issuing this AD to detect and correct damage in the wings and to prevent overload failure of the wing due to the installation of the STCs. Damage in the wing or overload failure of the wing could result in structural failure of the wing, which could result in loss of control.
Which aircraft AD 2010-21-18 applies to
Applies only to airplanes that are or have ever been modified by Aviation Enterprises Supplemental Type Certificate (STC) SA02055AT, SA02056AT, SA02307AT, or SA02308AT.
Whether AD 2010-21-18 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.