Airworthiness Directive · Amendment 39-11541 · McDonnell Douglas Model DC-9, DC-9-80, and C-9 (Military) Series Airplanes, and Model MD-88 Airplanes
McDonnell Douglas Model DC-9, DC-9-80, and C-9 (Military) Series Airplanes, and Model MD-88 Airplanes
Model DC-9-10, -20, -30, -40, and -50 series airplanes; Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes; Model MD-88 airplanes; and C-9 (military) series airplanes; as listed in McDonnell Douglas Alert Service Bulletin DC9-74A001, Revision 01, dated October 26, 1998; 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 adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 airplanes, that requires a one-time inspection to determine the type of engine ignition switch installed in the hinged forward overhead switch panel, and replacement of certain rotary ignition switches with new design rotary ignition switches. This amendment is prompted by reports of smoke in the flight compartment during engine ignition selection. The actions specified by this AD are intended to prevent an internal electrical short in the engine ignition switch, which could result in smoke in the flight compartment.
To prevent an internal electrical short in the engine ignition switch, which could result in smoke in the flight compartment, accomplish the following:
(a) Within 8 months after the effective date of this AD, visually inspect the engine ignition switch to determine what type of switch (rotary or toggle) is installed in the hinged forward overhead switch panel, in accordance with McDonnell Douglas Service Bulletin DC9-74-001, dated May 23, 1997, or McDonnell Douglas Alert Service Bulletin DC9-74A001, Revision 01, dated October 26, 1998.
Note 2: Inspection of the five position ignition switches prior the effective date of the AD in accordance with McDonnell Douglas Service Bulletin DC9-74001, dated May 23, 1997, is considered acceptable for compliance with paragraph (a) of this AD.
(1) If the switch is a toggle type, no further action is required by this AD.
(2) If the switch is a rotary type, prior to further flight, determine the switch part number in accordance with the service bulletin.
(i) If the switch has part number 79-2318 (5D0423-2) or 79-2355, no further action is required by this AD.
(ii) If the switch has any part number other than that identified in paragraph (a)(2)(i) of this AD, prior to further flight, replace the engine ignition switch with a new design ignition switch in accordance with the service bulletin.
(b) As of the effective date of this AD, no person shall install a four position rotary ignition type switch, part number (P/N) 79-2081, 69-1966, or 34064; or a five position rotary type ignition switch, P/N 79-2055 (5D0423-1), 69-1967, 53306-033, or 3600-3076; on any airplane.
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.
