Airworthiness Directive · Amendment 39-21990 · Flight control system
Bell Textron Inc., Helicopters
This AD applies to Bell Textron Inc., Model 412, 412EP, and 412CF helicopters, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for Bell Textron Inc., Model 412, 412EP, and 412CF helicopters. This AD was prompted by evaluation results showing flight loads that impact the collective lever fatigue life. This AD requires adding a permanent hours time-in-service (TIS) penalty for certain collective levers and prohibits installing those collective levers unless the permanent hours TIS penalty has been added. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 50 hours time-in-service (TIS) after the effective date of this AD:
(i) For helicopters with a Strake and FF system part number (P/N) 412-705-040-101 installed since initial delivery from the manufacturer, add a permanent penalty of 5,000 hours TIS to the total hours TIS indicated on the component history card or equivalent record for the collective lever P/N 412-010-408-101.
Note 1 to paragraph (g)(1)(i): Bell Helicopter service information identifies helicopters with serial numbers 36570, 36579, 36587, and 36593 through 36602 inclusive, as being originally delivered with a Strake and FF system installed and needing the flight hour (hours TIS) penalty on collective lever P/N 412-010-408-101 applied.
(ii) For helicopters with Strake and FF system P/N 412-705-040-101 installed after delivery from the manufacturer, calculate the TIS penalty for collective lever P/N 412-010-408-101 by accomplishing the following:
(A) Verify the component history card or equivalent record of the collective lever and note the total hours TIS.
(B) Determine the remaining hours TIS by subtracting the total hours TIS of the collective lever from its life limit of 10,000 total hours TIS.
(C) Divide the remaining time by 2 and add that number to the existing total hours TIS. This is the new total TIS after being penalized.
(D) Enter the new total TIS after being penalized from paragraph (g)(1)(ii)(C) of this AD to the component history record or equivalent record for the collective lever.
(2) Before further flight, remove from service any collective lever P/N 412-010-408-101 that has reached or exceeded its life limit of 10,000 total hours TIS. Thereafter, remove from service each collective lever P/N 412-010-408-101 on or before reaching its life limit of 10,000 total hours TIS.
(3) As of the effective date of this AD, do not install a new (zero total hours TIS) collective lever P/N 412-010-408-101 on any helicopter with Strake and FF system P/N 412-705-040-101 installed unless a penalty of 5,000 hours TIS has been added to the total hours TIS on its component history card or equivalent record.
(4) As of the effective date of this AD, do not install a used collective lever P/N 412-010-408-101 on any helicopter with Strake and FF system P/N 412-705-040-101 installed unless a penalty is calculated by accomplishing the actions required in paragraph (g)(1)(ii) of this AD.
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.
