Is AD 97-21788 a recurring Airworthiness Directive?

No — AD 97-21788 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 97-21788 apply to?

AD 97-21788 applies to Ayres Corporation S2R — models S2R. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 97-21788

one-time

AD 97-21788 · 1997-08-18 · airframe

Airworthiness Directives; Ayres Corporation S2R Series Airplanes

What this AD requires

This amendment supersedes Airworthiness Directive (AD) 97-13- 11, which currently requires inspecting the \1/4\-inch and \5/16\-inch bolt hole areas on the lower spar caps for fatigue cracking on Ayres S2R series airplanes, and replacing any lower spar cap if fatigue cracking is found. That AD resulted from an accident on an Ayres S2R series airplane where the wing separated from the airplane in flight. AD 97-13-11 incorrectly references the Ayres Model S2R-R1340 airplanes as Model S2R-1340R. This AD requires the same actions as AD 97-13-11, but corrects the designation of the Model S2R-R1340 airplanes. The actions specified by this AD are intended to detect fatigue cracking of the lower spar caps, which, if not corrected, could result in the wing separating from the airplane with consequent loss of control of the airplane.

Which aircraft AD 97-21788 applies to

MakesAyres Corporation S2R

ModelsS2R

applicability derived from the AD summary — confirm the model/serial from the records

Whether AD 97-21788 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 97-21788 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 →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.