Airworthiness Directive 99-17-17

one-time
Official AD 99-17-17 · FR doc 99-24535 · 1999-09-22 · airframe

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

What this AD requires

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-17-17 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (RHC) Model R44 helicopters by individual letters. This AD requires, prior to further flight, replacing certain yoke assemblies with airworthy yoke assemblies. This amendment is prompted by an incident in which, during cruise flight, the pilot heard a loud bang and no tail rotor effectiveness due to a cracked yoke assembly. RHC has identified the manufacturing lots associated with the failed yoke assembly. The actions specified by this AD are intended to prevent failure of the yoke assembly, which could result in loss of main and tail rotor drive and subsequent loss of control of the helicopter.

Which aircraft AD 99-17-17 applies to

MakesRobinson Helicopter Company
ModelsR44
Serial-conditional — narrows to serials 0219–0219, 0535–0608.
Part-conditionalC908-1C.

Yoke assembly P/N C908-1C, from Lot No. 36B, 37, or 38, was installed as original equipment in R44 helicopters S/N 0219 and S/N 0535 through 0608, EXCEPT S/N 0565, 0582, and 0592 (those three serials excluded). Inspect for affected lot; replace with a yoke assembly from a lot other than 36B, 37, or 38 per Robinson Helicopter Company R44 Service Bulletin SB-35, dated July 26, 1999.

Whether AD 99-17-17 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 complianceThe specific action taken (inspected, replaced, modified) and to what revision.
DateWhen the work was done.
Aircraft timeTotal time in service / tach at compliance — how recurring next-due is computed.
Signature & certificateThe A&P/IA who returned it to service, with certificate number.
Is AD 99-17-17 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.