Is AD 2021-20-13 a recurring Airworthiness Directive?

Yes — AD 2021-20-13 requires a repetitive inspection. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2021-20-13 apply to?

AD 2021-20-13 applies to Bombardier, Inc. — models CL-600-2B16, CL-600. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-20-13

recurring

Official AD 2021-20-13 · FR doc 2021-22295 · 2021-10-14 · airframe

Airworthiness Directives; Bombardier, Inc., Airplanes

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model CL-600-2B16 (604 Variant) airplanes. This AD was prompted by multiple reports of cracking of the main landing gear (MLG) shock strut lower pin. This AD requires repetitive lubrication and repetitive detailed visual inspections (DVI) and non- destructive test (NDT) inspections of the MLG shock strut lower pins, and replacement if necessary. The FAA is issuing this AD to address the unsafe condition on these products.

Repetitive inspection. Re-inspect. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2021-20-13 applies to

MakesBombardier, Inc.

ModelsCL-600-2B16, CL-600

Serial-conditional — narrows to serials 5301–5665, 5701–5988, 6050–6999.

604 Variant.

Whether AD 2021-20-13 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 2021-20-13 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.