Airworthiness Directive 51-12-01
one-timeAD 51-12-01 · 1951-01-01 · reciprocating engine
Airworthiness Directives; ) FOOTER: Wright Aeronautical Division, Curtiss-Wright Corporation Curtiss-Wright/Marquette, Inc. 718C9GB1 Military Cyclone R-1820
Which aircraft AD 51-12-01 applies to
MakesCurtiss-Wright
Models718C9GB1, 702C9GC1, 702C9GC2, 737C9HD4, 740C9HD1, 740C9HD2, 977C9HD1, 977C9HD2, 977C9HD3, Cyclone R-1820, Military Cyclone R-1820
Whether AD 51-12-01 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:
Method of compliance — The specific action taken (inspected, replaced, modified) and to what revision.
Date — When the work was done.
Aircraft time — Total time in service / tach at compliance — how recurring next-due is computed.
Signature & certificate — The A&P/IA who returned it to service, with certificate number.
Is AD 51-12-01 complied with on your aircraft?
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 →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.