Airworthiness Directive · Amendment 39-11957 · Boeing Model 767 Series Airplanes
Boeing Model 767 Series Airplanes
Model 767 series airplanes, line numbers 1 through 723 inclusive, certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes 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 (b) 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 adopts a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that requires modification of the canted pressure deck drain system in the wheel well of the main landing gear (MLG). This amendment is prompted by reports of ice accumulation on the aileron control cables and on the MLG door and door seal during flight, due to fluid entering the canted pressure deck area, leaking into the MLG wheel well, and freezing. The actions specified by this AD are intended to prevent such ice accumulation, which could render one of the aileron control systems and/or the MLG doors inoperative, resulting in reduced controllability of the airplane.
To prevent ice accumulation on the aileron control cables and/or main landing gear (MLG) door and door seal during flight, which could render one of the aileron control systems and/or the MLG doors inoperative, resulting in reduced controllability of the airplane, accomplish the following:
(a) Within 36 months after the effective date of this AD: Modify the canted pressure deck drain system in the wheel well of the MLG, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 767-51A0020, Revision 1, dated July 22, 1999.
Note 2: Modification of the canted pressure deck drain system accomplished prior to the effective date of this AD in accordance with Boeing Alert Service Bulletin 767-51A0020, dated November 19, 1998, is considered acceptable for compliance with the modification specified in this AD.
Note 3: Accomplishment of the actions specified in both Boeing Service Bulletins 767-53-0059, dated November 12, 1992, and 767-51-0019, dated June 27, 1996, is acceptable for compliance with paragraph (a) of this AD.
