# AD 85-24-01: Modifications In SB 49-2

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC-8-71, DC-8-72 and DC-8-73 with STC SA1387NM
- Effective: December 19, 1985
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-5169
- Registered aircraft: 3 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/37E0B71C7EF43BDB862569F2006BB79B.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/85-24-01

## The airworthiness directive

85-24-01 MCDONNELL DOUGLAS: Amendment 39-5169. Applies to McDonnell Douglas Model DC-8-70 series airplanes, equipped with an auxiliary power unit in accordance with STC SA1387NM.

Compliance is required as indicated.

To preclude potential APU exhaust door failures and resulting wiring and structural damage, accomplish the following, unless already accomplished:

A. Within six (6) months after the effective date of this AD, complete the modifications defined in McDonnell Douglas DC-8-70 Service Bulletin 49-2, dated May 16, 1985, or later revisions approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. The modifications involve removal of the APU; modification of the APU module and control boxes; revision of the APU control system sensing and firex control wiring; replacement of three generator phase circuit breakers; and the APU control and fuel supply circuit breakers; inspection of the wire routing; and reinstallation ofthe APU.

B. Special 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.

C. Alternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.

All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to the McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director, Publications and Training, C1-750 (54-60). These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or at 4344 Donald Douglas Drive, Long Beach, California.

This amendment becomes effective December 19, 1985.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A25](https://openairdocs.org/tcds/4A25): The Boeing Company; names 3 of 27 models: DC-8-73, DC-8-71, DC-8-72

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 3 (3 by airframe model, 0 by engine model)
- Makers: Douglas 3

Models with the most aircraft:

- [Douglas DC-8-73](https://openairdocs.org/model/douglas-dc-8-73): 2 aircraft (airframe model)
- [Douglas DC-8-72](https://openairdocs.org/model/douglas-dc-8-72): 1 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/85-24-01/models.md
Every aircraft: https://openairdocs.org/ad/85-24-01/aircraft.md

## Related documents

- [STC SA1387NM](https://openairdocs.org/stc/SA1387NM): Installation of a single or dual AiResearch GTCP85-98CK and/or GTCP-85-98CK(D) Auxiliary Power Units in the forward baggage compartment.. Airweld Inc., Named in the applicability

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.