Airworthiness Directive · Amendment 39-12054 · Boeing Model 747, 757, 767 and 777 Series Airplanes
Boeing Model 747, 757, 767 and 777 Series Airplanes
Superseded. A later AD replaced this one: AD 2005-17-09. Comply with the one in force.
Model 747, 757, 767, and 777 series airplanes having the line numbers listed below; certificated in any category.
| Model | Affected line numbers (L/N) | Except L/N |
|---|---|---|
| 747 | 1 through 1234 inclusive | 1174, 1216 |
| 757 | 2 through 895 inclusive | 870, 886, 894 |
| 767 | 1 through 768 inclusive | 758 |
| 777 | 2 through 254 inclusive | 120, 219, 230, 235, 242, 245, 249 |
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 (d) 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 747, 757, 767 and 777 series airplanes, that requires modification of certain drip shields located on the flight deck, and follow-on actions. This action is necessary to prevent potential ignition of the moisture barrier cover of the drip shield, which could propagate a small fire that results from an otherwise harmless electrical arc, leading to a larger fire. This action is intended to address the identified unsafe condition.
To prevent potential ignition of the moisture barrier cover of the drip shield, which could propagate a small fire that results from an otherwise harmless electrical arc, leading to a larger fire, accomplish the following:
(a) Within 6 years after the effective date of this AD, accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD; in accordance with Boeing Service Bulletin 747-25-3253, 767-25-0290, or 777-25-0164; all including Appendices A, B, and C; all dated June 29, 2000; or 757-25-0226 or 757-25-0228; both including Appendices A, B, and C; both dated July 3, 2000; as applicable; except as provided by paragraph (b) of this AD.
(1) Modify drip shields located on the flight deck by installing fire blocks.
(2) Prior to further flight following accomplishment of paragraph (a)(1) of this AD, perform a functional test of any system disturbed by the modification, in accordance with the applicable service bulletin or the Airplane Maintenance Manual (AMM), as applicable. If any functional test fails, prior to further flight, isolate the fault, correct the discrepancy in accordance with the applicable AMM, and repeat the failed test until it is successfully accomplished.
(3) Prior to further flight following the accomplishment of paragraphs (a)(1) and (a)(2) of this AD, install placards on all modified drip shields.
(b) If any wires or equipment are installed on the outboard surface of the drip shield (that is, between the drip shield and the airplane structure), modify that area in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.
(c) For Model 747 and 767 series airplanes listed in Group 1 in Boeing Service Bulletins 747-25-3253 and 767-25-0290: In lieu of accomplishment of paragraph (a) of this AD, within 6 years after the effective date of this AD, collect samples of the insulation and adhesive of the drip shields, and submit the samples to the manufacturer for testing, in accordance with Boeing Service Bulletin 747-25-3253 or 767-25-0290; both including Appendices A, B, and C; both dated June 29, 2000; as applicable.
(1) If the test on all samples is positive, no further action is required by this AD.
(2) If the test on any sample is negative, accomplish paragraph (a) of this AD before the compliance time specified in that paragraph.
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.
Aircraft
