# AD 76-21-01: C-1A Cargo Doors

- 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: November 20, 1976
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-2745
- Registered aircraft: 4 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6DD71C48716F9AFA862569750049187C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/76-21-01

## The airworthiness directive

76-21-01 LOCKHEED-CALIFORNIA COMPANY: Amendment 39-2745. Applies to Lockheed Model L-1011-385 series airplanes certificated in all categories having C-1A cargo door installed.

Compliance required within the next 300 hours' time in service after the effective date of this AD, unless already accomplished.

To prevent the latch pins on the latch fittings of the C-1A cargo door surround structure from being incorrectly installed during maintenance replacement, which could result in a possible in-flight loss of the C-1A cargo door, accomplish the following:

a. Install latch pin guard assemblies and related components, reidentify the latch fitting assemblies and check proximity sensors adjustment as necessary, on the C-1A cargo door surround structure, in accordance with Lockheed-California Company Service Bulletin 093-52-083 dated May 25, 1976, or later FAA-approved revision or equivalent modification approved by the Chief, Aircraft Engineering Division, FAA Western Region.b. Airplanes may be flown in accordance with FAR 21.197 to a base where the modification can be performed.

This amendment becomes effective November 20, 1976.

## 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/76-21-01/models.md
Every aircraft: https://openairdocs.org/ad/76-21-01/aircraft.md

Its text cites no advisory circulars or STCs.

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