Airworthiness Directive · Amendment 39-11670 · McDonnell Douglas Model MD-11 and MD-11F Series Airplanes
McDonnell Douglas Model MD-11 and MD-11F Series Airplanes
Model MD-11 and MD-11F series airplanes, as listed in McDonnell Douglas Service Bulletin 24-78, dated May 10, 1994; 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 (c) 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), applicable to certain McDonnell Douglas Model MD-11 and MD-11F series airplanes, that currently requires modification of the external power feeder cable clamping installation. This amendment also requires a detailed visual inspection of the external power feeder cables to detect chafed or damaged wires; and repair, if necessary. This amendment is prompted by reports of damage to the external power feeder cables located under the forward cargo compartment floor, which was caused by excessive cable length and/or maintenance personnel stepping on the cables. The actions specified by this AD are intended to prevent arcing from occurring under the forward cargo compartment floor as a result of damaged external power feeder cables, a situation that could lead to a fire at this location.
To prevent arcing from occurring under the forward cargo compartment floor as a result of damaged external power feeder cables, a situation that could lead to a fire at this location, accomplish the following:
(a) Within 90 days after June 15, 1994 (the effective date of AD 94-11-06, amendment 39-8922), modify the external power feeder cable clamping installation in accordance with McDonnell Douglas Service Bulletin 24-78, dated May 10, 1994, or McDonnell Douglas Alert Service Bulletin MD11-24A078, Revision 01, dated June 16, 1999.
(b) Within 1 year after the effective date of this AD, perform a detailed visual inspection of the external power cables between stations Y=635.000 and Y=655.000 to detect chafed or damaged wires, in accordance with McDonnell Douglas Alert Service Bulletin MD11-24A078, Revision 01, dated June 16, 1999. If any chafed or damaged wire is found, prior to further flight, repair in accordance with the service bulletin.
Note 2: For the purposes of this AD, a detailed visual inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”
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.
