Airworthiness Directive 91-21-03
one-timeAD 91-21-03 · 1991-01-01 · airframe
Airworthiness Directives; INFORMATION: REGULATORY TEXT: 91-21-03 MCDONNELL DOUGLAS: Amendment 39-8050. Docket No. 91-NM-74-AD. Applicability: Model DC-9 ser
Which aircraft AD 91-21-03 applies to
MakesInformation Regulatory Text 91-21-03 Mcdonnell Douglas Amendment 39-8050 Docket No 91-Nm-74-Ad Applicability
ModelsDC-9
Whether AD 91-21-03 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 91-21-03 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.