# AD 93-05-20: Hydraulic Pump Overtemperature Switches

- Type: Airworthiness directive
- Status: Current
- Products: Boeing MD-11 and MD-11F
- Effective: April 30, 1993
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-8524
- Docket: 92-NM-169-AD
- Registered aircraft: 108 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D6A63635FFDB55DA86256A080065BD57.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/93-05-20

## The airworthiness directive

93-05-20 MCDONNELL DOUGLAS: Amendment 39-8524. Docket 92-NM-169-AD.

Applicability: Model MD-11 series airplanes equipped with Pratt & Whitney Model PW4460 engines; having airplane serial numbers 48407 through 48410 inclusive, 48443 through 48448 inclusive, 48452 through 48457 inclusive, 48461, 48472 through 48475 inclusive, 48484, 48485, 48495, and 48496; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent loss of a hydraulic system, accomplish the following:

  (a) Within 60 days after the effective date of this AD, modify the wiring to the engine-driven hydraulic pump overtemperature switches, in accordance with McDonnell Douglas MD-11 Service Bulletin 29-16, dated August 6, 1992.

  (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, TransportAirplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

  (c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

  (d) The modification shall be done in accordance with McDonnell Douglas MD-11 Service Bulletin 29-16, dated August 6, 1992. 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 McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, California 90846-1771, Attention: Business Unit Manager, Technical Publications - Technical Administrative Support, C1-L5B. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office (ACO), 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

  (e) This amendment becomes effective on April 30, 1993.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A22WE](https://openairdocs.org/tcds/A22WE): The Boeing Company; names 2 of 11 models: MD-11, MD-11F

## 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: 108 (108 by airframe model, 0 by engine model)
- Makers: Mcdonnell Douglas 104, Boeing 4

Models with the most aircraft:

- [Mcdonnell Douglas MD-11F](https://openairdocs.org/model/mcdonnell-douglas-md-11f): 100 aircraft (airframe model)
- [Mcdonnell Douglas MD-11](https://openairdocs.org/model/mcdonnell-douglas-md-11): 4 aircraft (airframe model)
- [Boeing MD-11F](https://openairdocs.org/model/boeing-md-11f): 4 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/93-05-20/models.md
Every aircraft: https://openairdocs.org/ad/93-05-20/aircraft.md

Its text cites no advisory circulars or STCs.

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