Airworthiness Directive · Amendment 39-21433 · Tail rotor drive shaft
Robinson Helicopter Company Helicopters
This airworthiness directive (AD) applies to Robinson Helicopter Company (Robinson) Model R66 helicopters, certificated in any category, with a tail rotor (T/R) drive shaft assembly part number (P/N) D224-3 without B900-11 modification installed.
Note 1 to paragraph (a): Helicopters with serial number (S/N) 0631 and subsequent had T/R drive shaft assembly P/N D224-4 installed during production, which is not affected by this AD.
The FAA is adopting a new airworthiness directive (AD) for Robinson Helicopter Company (Robinson) Model R66 helicopters. This AD was prompted by reports of tail rotor (T/R) drive shaft forward hanger bearing failures. This AD requires installing a certain part numbered kit and removing parts from service or replacing a certain part- numbered T/R drive shaft assembly. This AD also prohibits the installation of certain parts. The FAA is issuing this AD to address the unsafe condition on these products.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) Within 100 hours time-in-service, do one of the following:
(i) Install Robinson kit P/N KI-235 using KI-235 R66 TRDS Forward Yoke Assembly and Hanger Installation Kit Instructions, Revision A, dated June 23, 2015, except where the service information specifies discarding parts, you are required to remove those parts from service instead.
(ii) Replace the entire T/R drive shaft assembly with T/R drive shaft assembly P/N D224-4.
(2) As of the effective date of this AD, do not install a T/R drive shaft assembly P/N D224-3 without B900-11 modification on any helicopter.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
