# AD 91-23-12: Main Landing Gear Braking Effectiveness

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed Martin L-1011-385-1, L-1011-385-1-14, L-1011-385-1-15 and L-1011-385-3
- Effective: December 9, 1991
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-8081
- Docket: 91-NM-77-AD
- Registered aircraft: 4 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/BB53A9155EF350D786256A2B00464C62.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/91-23-12

## The airworthiness directive

91-23-12 LOCKHEED: Amendment 39-8081. Docket No. 91-NM-77-AD.

Applicability: Model L-1011 series airplanes, equipped with BFGoodrich brake part numbers identified in paragraph (a) of this AD, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent the loss of main landing gear braking effectiveness, accomplish the following:

  (a) Within 180 days after the effective date of this AD, inspect the brake part numbers shown below for wear. Any brake worn more than the maximum wear limit specified below must be replaced, prior to further flight, with a brake within this limit.

Type Certificated Model Designation Common Model Designation Maximum GTOW Brake Part No. Maximum Wear Limit (inches) L-1011-385-1 (-1) 430,000 2-1195-1 2.10

(-1) 430,000 2-1195-5 2.10

(-1) 430,000 2-1195-6 2.10

(-1) 430,000 2-1195-7 2.10

(-1) 430,000 2-1195-8 2.10

(-1) 430,000 2-1367 3.00

(-1) 430,000 2-1367-1 3.00

(-1) 430,000 2-1367-2 3.00

(-40) 440,000 2-1195-1 2.10

(-40) 440,000 2-1195-5 2.10

(-40) 440,000 2-1195-6 2.10

(-40) 440,000 2-1195-7 2.10

(-40) 440,000 2-1195-8 2.10

(-40) 440,000 2-1367 3.00

(-40) 440,000 2-1367-1 3.00

(-40) 440,000 2-1367-2 3.00

(-50) 450,000 2-1367-3 2.60

(-50) 450,000 2-1367-4 2.60

(-50) 450,000 2-1367-5 2.60

L-1011-385-1-14 (-100,-150,-200) 466,000 2-1367-3 2.60

(-100,-150,-200) to 2-1367-4 2.60

(-100,-150,-200) 474,000 2-1367-5 2.60

(-250) 510,000 2-1367 3.00

(-250) 510,000 2-1367-1 3.00

(-250) 510,000 2-1367-2 3.00

L-1011-385-1-15 (-100,-150,-200) 466,000 2-1367-3 2.60

(-100,-150,-200) to 2-1367-4 2.60

(-100,-150,-200) 474,000 2-1367-5 2.60

(-250) 510,000 2-1367 3.00

(-250) 510,000 2-1367-1 3.00

(-250)510,000 2-1367-2 3.00

L-1011-385-3 (-500) 496,000 2-1367 3.00

(-500) to 2-1367-1 3.00

(-500) 516,000 2-1367-2 3.00

NOTE: Lockheed Service Bulletin 093-32-253, dated March 29, 1991, contains additional information concerning Model L-1011 brake configurations.

  (b) Within 180 days after the effective date of this AD, incorporate the maximum brake wear limits specified in paragraph (a) of this AD into the FAA-approved maintenance inspection program.

  (c) An 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, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles ACO.

  (d) 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.

This amendment (39-8081, AD 91-23-12) becomes effective on December 9, 1991.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A23WE](https://openairdocs.org/tcds/A23WE): Lockheed Martin Corporation; names 4 of 4 models: L-1011-385-1-14, L-1011-385-3, L-1011-385-1, L-1011-385-1-15

## 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: 4 (4 by airframe model, 0 by engine model)
- Makers: Lockheed 4

Models with the most aircraft:

- [Lockheed L-1011-385-1](https://openairdocs.org/model/lockheed-l-1011-385-1): 2 aircraft (airframe model)
- [Lockheed L-1011-385-1-15](https://openairdocs.org/model/lockheed-l-1011-385-1-15): 1 aircraft (airframe model)
- [Lockheed L-1011-385-3](https://openairdocs.org/model/lockheed-l-1011-385-3): 1 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/91-23-12/models.md
Every aircraft: https://openairdocs.org/ad/91-23-12/aircraft.md

Its text cites no advisory circulars or STCs.

---
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.