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91-21-03: Electrical Wiring

FAA order 91-21-03 is an airworthiness directive in force since November 29, 1991. The FAA's subject line: Electrical Wiring. It names Douglas DC-9, Mcdonnell Douglas DC-9: about 100 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: electrical power.

What it applies to as the FAA lists it

Kind of product
Aircraft
Makes
The Boeing Company
Models
DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A), DC-9-32F (C-9B), DC-9-33F, DC-9-34, DC-9-34F, DC-9-41, DC-9-51, DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87)
On this site
Douglas DC-9 7 registered
Mcdonnell Douglas DC-9 93 registered

Dates and paperwork

In force since
November 29, 1991
Docket
91-NM-74-AD
Status
Current
The FAA's document
Read the order on the FAA's site

The order itself the regulatory text, as published

Show the full text (2,361 characters)
91-21-03 MCDONNELL DOUGLAS: Amendment 39-8050. Docket No. 91-NM-74-AD. \n\n\tApplicability: Model DC-9 series airplanes, listed in Heath Tecna Service Bulletin ESCI-25-A1, dated April 30, 1990, certificated in any category. \n\n\tCompliance: Required within 18 months after the effective date of this AD, unless previously accomplished. \n\n\tTo prevent the occurrence of fire and smoke in the passenger cabin, accomplish the following: \n\n\t(a)\tVisually inspect the electrical wiring along the left and right overhead stowage compartment rail assemblies in the vicinity of each electrical bonding strap for evidence of arcing, burning, or chafing. If damage is found, prior to further flight, repair in accordance with McDonnell Douglas DC-9 Maintenance Manual, Chapters 20-50-01 and 20-50-02. \n\n\t(b)\tModify the electrical bonding strap installation of the left and right overhead stowage compartment rail assemblies in accordance with Heath Tecna Aerospace Co. Alert Service Bulletin ESCI-25-A1, dated April 30, 1990. \n\n\t(c)\tAn alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO. \n\n\t(d)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. \n\n\t(e)\tThe modification requirements of this rule shall be done in accordance with Heath Tecna Aerospace Company Alert Service Bulletin ESCI-25-A1, dated April 30, 1990. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Heath Tecna Aerospace Company, 19819 84th Avenue South, Kent, Washington 98032. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington, or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C. \n\n\tThis amendment (39-8050, AD 91-21-03) becomes effective on November 29, 1991.

Related safety bulletins advice on the same designs, not orders

2019-02-19NE-19-03 · Escape Slide Maintenance Tasks and Intervals - JASC 2565
2014-11-24NM-15-03 · Flight Controls
2008-09-03NM-08-43 · Cabin Equipment/Furnishings - Seats
2006-07-27NM-06-57 · Reports of damage to airplanes and to property on the ground caused by blue or clear ice falling from airplanes.

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/91-21-03.json · aircraft systems.