Airworthiness Directive · Amendment 39-19880 · Main rotor control
MD Helicopters Inc. Helicopters
This AD applies to MD Helicopters Inc. (MDHI) Model 600N helicopters, certified in any category, with a yaw stability augmentation system and with a main rotor (M/R) blade upper control collective/longitudinal link assembly (link assembly) part number (P/N) 600N7617-1 installed.
The FAA is adopting a new airworthiness directive (AD) for MD Helicopters Inc. (MDHI) Model 600N helicopters. This AD requires establishing a life limit for the main rotor (M/R) blade upper control collective/longitudinal link assembly (link assembly). This AD was prompted by the discovery that the life limit was omitted from the maintenance manual. The actions of this AD are intended to prevent an 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.
Within 100 hours time-in-service (TIS):
(1) Determine the total hours TIS of each link assembly P/N 600N7617-1. If the hours TIS are unknown, use the hours TIS of the helicopter. Remove from service any link assembly that has 15,000 or more hours TIS. Thereafter, remove from service any link assembly before accumulating 15,000 hours TIS.
(2) Create a component history card or equivalent record for each link assembly P/N 600N7617-1 and record a life limit of 15,000 hours TIS.
(3) As an optional terminating action to the requirements of paragraphs (e)(1) and (2) of this AD, you may remove from service link assembly P/N 600N7617-1 and install link assembly P/N 600N7617-5.
