Airworthiness Directive · Amendment 39-19661 · Tail rotor driveshaft
Leonardo S.p.A. Helicopters
This AD applies to Model AW139 helicopters, serial numbers 31499, 31504, 31507, 31509, 31512, 31518, 31519, 31524, 31529, 31533, 31535 through 31564, 31567, 31569, 31570, 31589, 41363, 41368 through 41370, 41372 through 41375, 41378, 41381, and 41384, with a tunnel assembly part number (P/N) 3G7130A13431 installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for Leonardo S.p.A. (type certificate previously held by Finmeccanica S.p.A., AgustaWestland S.p.A.) Model AW139 helicopters. This AD requires inspecting and altering the number 1 driveshaft (driveshaft). This AD was prompted by reports of scratches that were found on the driveshaft. The actions of this AD are intended to address 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.
(1) Within 30 hours time-in-service (TIS) and thereafter at intervals not to exceed 100 hours TIS, inspect the number 1 driveshaft tube shaft, P/N 3G6510A00832, for a scratch and indentation in the area depicted in Figure 1 of Leonardo Helicopters Bollettino Tecnico No. 139-465, Revision A, dated January 25, 2017 (BT 139-465). If there is a scratch or indentation, before further flight:
(i) Repair the tube shaft in accordance with the Compliance Instructions, Part I, paragraphs 7.1 through 7.3, of BT 139-465.
(ii) Measure the depth of the repaired areas as depicted in Figure 2 of BT 139-465.
(A) If the depth of the reworked area is 0.2 mm (0.079 inch) or less, eddy-current inspect the driveshaft for a crack as described in the Compliance Instructions, Annex A, of BT 139-465. If there is a crack, before further flight, replace the driveshaft, alter the rear exhaust module, and alter and re-identify the tunnel assembly in accordance with the Compliance Instructions, Part II, paragraphs 7 through 12, of BT 139-465.
(B) If the depth of the reworked area is more than 0.2 mm (0.079 inch), before further flight, replace the driveshaft, alter the rear exhaust module, and alter and re-identify the tunnel assembly in accordance with the Compliance Instructions, Part II, paragraphs 7 through 12, of BT 139-465.
(2) Within 300 hours TIS, unless already accomplished as required by paragraph (e)(1)(ii) of this AD, alter the rear exhaust module and alter and re-identify the tunnel assembly in accordance with the Compliance Instructions, Part II, paragraphs 7 through 12, of BT 139-465.
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.
