Is AD 2018-21-01 a recurring Airworthiness Directive?

No — AD 2018-21-01 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2018-21-01 apply to?

AD 2018-21-01 applies to Honeywell International Inc. — models AS907-1-1A, AS907. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2018-21-01

one-time

Official AD 2018-21-01 · FR doc 2018-22009 · 2018-10-15 · turbine engine

Airworthiness Directives; Honeywell International Inc. Turbofan Engines

What this AD requires

We are superseding Airworthiness Directive (AD) 2017-20-06 for certain Honeywell International Inc. (Honeywell) AS907-1-1A turbofan engines. AD 2017-20-06 required a one-time inspection of the second stage low-pressure turbine (LPT2) blades and, if the blades fail the inspection, the replacement of the blades with a part eligible for installation. This AD continues to require a one-time inspection of the LPT2 blades and, if the blades fail the inspection, the replacement of the blades with a part eligible for installation. This AD was prompted by the need to clarify the Applicability and Compliance sections of AD 2017-20-06. We are issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2018-21-01 applies to

MakesHoneywell International Inc.

ModelsAS907-1-1A, AS907

Part-conditional — 3035602-1.

Applies only to engines with LPT2 rotor blade P/N 3035602-1 installed and more than 8,000 hours since new as of November 9, 2017 (effective date of AD 2017-20-06).

Whether AD 2018-21-01 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 2018-21-01 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.