Is AD 99-13-09 a recurring Airworthiness Directive?

Yes — AD 99-13-09 requires a repetitive inspection every 50 hours. Next-due depends on the aircraft's time in service.

Which aircraft does AD 99-13-09 apply to?

AD 99-13-09 applies to Md Helicopters, Inc. — models 369D, 369E, 369. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 99-13-09

recurring

Official AD 99-13-09 · FR doc 99-18367 · 1999-07-20 · airframe

Airworthiness Directives; MD Helicopters, Inc (MDHI) Model 369D and E Helicopters

What this AD requires

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-13-09 which was sent previously to all known U.S. owners and operators of MDHI Model 369D and E helicopters by individual letters. This AD requires, prior to further flight, inspecting and replacing, if necessary, a certain four- bladed tail rotor fork (fork) assembly. This AD also requires a repetitive inspection of certain fork assemblies at intervals not to exceed 50 hours time-in-service (TIS) and removing and replacing, if necessary, each unairworthy fork assembly with an airworthy fork assembly before further flight. This amendment is prompted by reports from the manufacturer of the discovery of a discrepant part. The actions specified by this AD are intended to prevent failure of certain fork assemblies, which could cause loss of a tail rotor blade and subsequent loss of control of the helicopter.

Repetitive inspection. Re-inspect every 50 hours. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 99-13-09 applies to

MakesMd Helicopters, Inc.

Models369D, 369E, 369

Part-conditional — 369D21701-21.

Applies to helicopters with tail rotor fork assembly (titanium) P/N 369D21701-21. Applicability derived from referenced MD Helicopters, Inc. Service Bulletins SB369D-198 (Model 369D) and SB369E-092 (Model 369E), dated May 10, 1999. Inspect each fork assembly for ridges; if no ridges, dye-penetrant and visual inspect for cracks, replace cracked fork; thereafter repetitive visual inspection every 50 hr TIS. A fork assembly without ridges other than P/N 369D21701-21 may not be installed; replacing with an airworthy fork other than the affected P/N terminates the AD. Text truncated mid-procedure in the source slice.

Whether AD 99-13-09 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 99-13-09 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.