Is AD 2014-17921 a recurring Airworthiness Directive?

Yes — AD 2014-17921 requires a repetitive inspection every 2400 hours or 6 months. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2014-17921 apply to?

AD 2014-17921 applies to Beechcraft Corporation — models MU-300, 400, 400A, 400T (T-1A), 400T (TX). Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2014-17921

recurring

AD 2014-17921 · 2014-08-01 · airframe

Airworthiness Directives; Beechcraft Corporation Airplanes

What this AD requires

We are adopting a new airworthiness directive (AD) for certain Beechcraft Corporation (Type Certificate Previously Held by Hawker Beechcraft Corporation; Raytheon Aircraft Company; Mitsubishi Heavy Industries, Inc. Ltd.) Model MU-300 airplanes, and Beechcraft Corporation (Type Certificate Previously Held by Hawker Beechcraft Corporation; Raytheon Aircraft Company; Beech Aircraft Corporation) Model 400, 400A, and 400T airplanes. This AD was prompted by multiple reports of fatigue cracking in the horizontal stabilizer ribs. This AD requires repetitive inspections of the horizontal stabilizer rib assemblies for cracking, and replacement if necessary. We are issuing this AD to detect and correct such cracking, which could result in the failure of the horizontal stabilizer and loss of pitch control of the airplane.

Repetitive inspection. Re-inspect every 2400 hours or 6 months. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2014-17921 applies to

MakesBeechcraft Corporation

ModelsMU-300, 400, 400A, 400T (T-1A), 400T (TX)

Serial-conditional — narrows to serials A003SA–A093SA, RJ-1–RJ-65, RK-1–RK-604, TT-1–TT-180, TX-1–TX-13.

Serial ranges are per model: MU-300 A003SA through A093SA; Model 400 RJ-1 through RJ-65; Model 400A RK-1 through RK-604; Model 400T (T-1A) TT-1 through TT-180; Model 400T (TX) TX-1 through TX-13.

Whether AD 2014-17921 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 2014-17921 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.