Airworthiness Directive · Amendment 39-11734 · Eurocopter France Model AS-350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N Helicopters
Eurocopter France Model AS-350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N Helicopters
Superseded. A later AD replaced this one: AD 2000-25-08. Comply with the one in force.
Model AS-350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N helicopters, with main gearbox suspension bi-directional cross-beam (cross-beam), part number (P/N) 350A38-1018—all dash numbers, installed, certificated in any category.
Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment supersedes an existing airworthiness directive (AD) that applies to Eurocopter France Model AS-350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N helicopters and requires inspecting the main gearbox suspension bi-directional cross-beam (cross-beam) for cracks, and replacing the cross-beam if a crack is found. This amendment requires the same inspections as the existing AD, but adds the time intervals for performing repetitive dye-penetrant inspections on cross-beams with 5,000 or more hours time-in-service (TIS). This amendment is prompted by the discovery that time intervals for performing the required dye-penetrant inspections are not included in the existing AD. The actions specified by this AD are intended to prevent failure of the cross-beam that could lead to rotation of the main gearbox, resulting in severe vibrations and a subsequent forced landing.
To prevent failure of the cross-beam that could lead to rotation of the main gearbox, resulting in severe vibrations and a subsequent forced landing, accomplish the following:
(a) For cross-beams having 2,000 or more hours time-in-service (TIS) or 10,000 or more operating cycles, whichever occurs first:
Note 2: The Master Service Recommendations and the flight log contain accepted procedures that are used to determine the cumulative operating cycles on the rotorcraft.
(1) Within 30 hours TIS, and thereafter at intervals not to exceed 30 hours TIS or 150 operating cycles, whichever occurs first, visually inspect the cross-beam for cracks in accordance with paragraph 2.B.1) of Eurocopter France Service Bulletin No. 05.00.28, applicable to Model AS-350 helicopters, or Eurocopter France Service Bulletin No. 05.00.29, applicable to Model AS-355 helicopters, both dated May 26, 1997.
(2) If a crack is found, remove the cross-beam and replace it with an airworthy cross-beam.
(b) For cross-beams having 5,000 or more hours TIS:
(1) In addition to continuing the repetitive inspections of paragraph (a)(1), before further flight, and thereafter at intervals not to exceed 550 hours TIS or 2,750 operating cycles, whichever occurs first, perform a dye-penetrant inspection in accordance with paragraph 2.B.2) of Eurocopter France Service Bulletin No. 05.00.28, applicable to Model AS-350 helicopters, or Eurocopter Service Bulletin No. 05.00.29, applicable to Model AS-355 helicopters, both dated May 26, 1996.
(2) If a crack is found, remove the cross-beam and replace it with an airworthy cross-beam.
(c) Prior to installing any replacement cross-beams, regardless of TIS or operating cycles, inspect the replacement cross-beam in accordance with paragraph (b)(1) of this AD.
(d) Modifying the helicopter in accordance with paragraph 2.B of the Accomplishment Instructions in Eurocopter Service Bulletin No. 63.00.07, applicable to Model AS-350B, BA, B1, B2, and D helicopters, or Eurocopter Service Bulletin No. 63.00.13, applicable to Model AS-355E, F, F1, F2, and N helicopters, both dated April 7, 1997, constitutes terminating action for the requirements of this AD.
