Is AD 70-21-03 a recurring Airworthiness Directive?

No — AD 70-21-03 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 70-21-03 apply to?

AD 70-21-03 applies to Messerschmitt-Bolkow-Blohm — models Phoebus. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 70-21-03

one-time

AD 70-21-03 · 1970-01-01 · airframe

Airworthiness Directives; the effective date of this AD, unless already accomplished, replace the chute coupling with a modified coupling in accordance with

Which aircraft AD 70-21-03 applies to

MakesMesserschmitt-Bolkow-Blohm

ModelsPhoebus

Requires replacement of parachute/tow chute coupling with a modified coupling per Service Bulletin No. Phoebus-1/70, dated April 1970; likely applies to the Phoebus glider series based on the service bulletin designation, though not explicitly restated in the extracted applicability text.

Whether AD 70-21-03 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 70-21-03 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.