Airworthiness Directive · Amendment 39-18682 · Main rotor head
Bell Helicopter Textron Helicopters
This AD applies to Model 430 helicopters, serial number 49001 through 49129, with a main rotor head attachment bolt (bolt) part number (P/N) MS21250-08083 installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for certain Bell Helicopter Textron (Bell) Model 430 helicopters. This AD requires establishing a life limit for a certain main rotor hub attachment bolt (bolt) and removing from service each bolt that has met or exceeded its life limit. This AD was prompted by a documentation error that omitted the life limit of a certain part-numbered bolt from the Airworthiness Limitations section of the maintenance manual. The actions of this AD are intended to establish a life limit for a certain part-numbered bolt to prevent failure of a bolt, failure of a main rotor hub, and subsequent loss of control of a helicopter.
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.
Within 10 hours time-in-service (TIS):
(1) Revise the Airworthiness Limitations section of the applicable maintenance manual or Instructions for Continued Airworthiness (ICA) to establish a life limit of 5,000 hours TIS for each bolt P/N MS21250-08083.
(2) Determine the number of hours TIS for each bolt and update the helicopter's historical records. If the hours TIS is unknown, calculate the number of hours TIS by counting the helicopter's hours TIS beginning January 1, 2009.
(3) Remove from service each bolt that has reached or exceeded its life limit.
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.
