Airworthiness Directive 2021-23656

recurring
AD 2021-23656 · 2021-11-01 · airframe

Airworthiness Directives; De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-400, -401, and -402 airplanes. This AD was prompted by a report of cracking found on a main landing gear (MLG) drag strut assembly. This AD requires a records review to determine if an affected MLG drag strut assembly is installed, repetitive detailed inspections for cracking of affected strut assemblies, a one-time magnetic particle inspection for cracking, and on-condition actions 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 2021-23656 applies to

MakesDe Havilland Aircraft Of Canada Limited
ModelsDHC-8-400, DHC-8-401, DHC-8-402, DHC-8
Serial-conditional — narrows to serials 4001–4001, 4003–?.

Serial numbers 4001, 4003, and subsequent.

Whether AD 2021-23656 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 complianceThe specific action taken (inspected, replaced, modified) and to what revision.
DateWhen the work was done.
Aircraft timeTotal time in service / tach at compliance — how recurring next-due is computed.
Signature & certificateThe A&P/IA who returned it to service, with certificate number.
Is AD 2021-23656 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.