Is AD 2008-17-51 a recurring Airworthiness Directive?

No — AD 2008-17-51 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2008-17-51 apply to?

AD 2008-17-51 applies to Md Helicopters — models MD900. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2008-17-51

one-time

Official AD 2008-17-51 · FR doc E8-28367 · 2008-12-24 · airframe

Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

What this AD requires

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2008-17-51, which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model MD900 helicopters by individual letters. This AD requires, before further flight, fluorescent magnetic particle inspecting the aft threads of the forward directional control cable (control cable) for a crack and replacing the control cable with an airworthy part if you find a crack. If you do not find a crack, this AD requires that you demagnetize the cable threads until you reach a certain gauss level. This AD also requires visually inspecting the aft cable attach bracket for a crack and for interference with movement of the control cable or for deformation of the aft cable attach bracket. If a crack or interference with movement of the control cable or deformation of the aft cable attach bracket exists, this AD requires replacing the bracket with an airworthy part. This AD also requires modifying the control cable conduit and the rotating cone control rod and identifying the rotating cone control rod with a certain part number. This amendment is prompted by three reports of in-flight failure of the control cable and loss of yaw control resulting in emergency landings and subsequent damage to the helicopter. The actions specified by this AD are intended to prevent loss of yaw control and subsequent loss of control of the helicopter.

Which aircraft AD 2008-17-51 applies to

MakesMd Helicopters

ModelsMD900

Serial-conditional — narrows to serials 900-00008–900-00128.

Part-conditional — 900C3010045-105, 900C2010582-103, 9000F2318021.

Applies only when forward directional control cable P/N 900C3010045-105, rotating cone control rod P/N 900C2010582-103, and tailboom assembly P/N 9000F2318021 (all dash numbers) are installed.

Whether AD 2008-17-51 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 2008-17-51 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.