# AD 75-12-11: Auto Flight Pitch Computer

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed Martin L-1011-385-1, L-1011-385-1-14 and L-1011-385-1-15
- Effective: September 2, 1975
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-2349
- Registered aircraft: 3 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F77B44E2CA29912F86256E520053AF46.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/75-12-11

## The airworthiness directive

75-12-11 LOCKHEED: Amendment 39-2234 as amended by Amendment 39-2349. Applies to L-1011-385-1 Series airplanes, certificated in all categories with Collins FCS-110 autopilot installed.

To prevent possible unwanted pitch-up while in the autoland mode, accomplish the following:

  (1) Effective 48 hours after receipt of this telegram, the following operating limitation applies: 'Autopilot command mode use prohibited below 100 feet AGL', and a placard must be installed in plain view of the pilots stating:

'AUTOPILOT CMD MODE USE PROHIBITED BELOW 100' AGL'.

  (2) Operators shall, by the most immediate and practicable means, notify flight crews of the foregoing.

  (3) When an operator's entire fleet, including spares, incorporates the auto flight pitch computer modification described in Lockheed Service Bulletin 093-22-080, dated August 11, 1975, or later FAA-approved revisions, remove the operating limitation and placard.

Amendment 39-2234 was effective 6-12-75 for allpersons except those to whom it was made effective immediately by telegrams dated May 14, 1975.

This amendment 39-2349 is effective September 2, 1975.

## 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 3 of 4 models: L-1011-385-1-14, 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: 3 (3 by airframe model, 0 by engine model)
- Makers: Lockheed 3

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)

All 2 models: https://openairdocs.org/ad/75-12-11/models.md
Every aircraft: https://openairdocs.org/ad/75-12-11/aircraft.md

Its text cites no advisory circulars or STCs.

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