Is AD 2017-21-05 a recurring Airworthiness Directive?

No — AD 2017-21-05 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2017-21-05 apply to?

AD 2017-21-05 applies to Saab — models 340A, SF340A, 340B, 340. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2017-21-05

one-time

Official AD 2017-21-05 · FR doc 2017-22562 · 2017-10-23 · airframe

Airworthiness Directives; Saab AB, Saab Aeronautics (Formerly Known as Saab AB, Saab Aerosystems) Airplanes

What this AD requires

We are adopting a new airworthiness directive (AD) for certain Saab AB, Saab Aeronautics Model 340A (SAAB/SF340A) and SAAB 340B airplanes. This AD was prompted by the determination that new inspection tasks for the drag brace support fitting of the main landing gear (MLG) and corrosion prevention and control program (CPCP) related tasks are necessary. This AD requires revising the maintenance or inspection program, as applicable, to incorporate airworthiness limitations, including new inspection tasks for the drag brace support fitting of the MLG and to implement CPCP related tasks. We are issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2017-21-05 applies to

MakesSaab

Models340A, SF340A, 340B, 340

Applies to airplanes with an original certificate of airworthiness or original export certificate of airworthiness issued on or before December 1, 2016. Model 340A is also identified as SAAB/SF340A.

Whether AD 2017-21-05 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 2017-21-05 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.