# AD 56-16-02: Automatic Pilot Servo Brackets

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed 1049-54, 1049B-55 (Navy R7V-1), 1049C-55, 1049D-55, 1049E-55, 1049F-55 (USAF C-121C), 1049G-82, 1049H-82, 149-46, 49-46, 649-79, 649A-79 and 2 more
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 3 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E8E84B6B3949D29786256975004949DB.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/56-16-02

## The airworthiness directive

56-16-02 LOCKHEED: Applies to All Models 49, 149, 649, 749 and 1049 Series Aircraft Equipped With Bendix Eclipse-Pioneer Type PB-10 Series Automatic Pilot Installations.

Compliance required as indicated.

Numerous instances of fatigue failures have been reported in the side webs of the Bendix Eclipse-Pioneer Type DQ-15 Series servo disconnect mounting brackets in the primary flight control system. Since complete failure could result in disabling the flight control system, the following must be accomplished as indicated:

1. The rudder and elevator servo disconnect mounting bracket installations in the primary flight control system must be inspected by dye penetrant or equivalent method, at 125-hour intervals until item 2 is accomplished. Defective servo mounting brackets must be discarded.

2. To be accomplished as soon as possible but not to exceed next overhaul period after parts become available. The rudder and elevator servo must be reinforced by installation of a secondary servo support bracket to provide additional support and vibration dampening.

(Bendix Eclipse-Pioneer Service Bulletin No. 858 and Lockheed Service Bulletins Nos. 49-864 and 1049-2830 also cover this subject.)

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 6A5](https://openairdocs.org/tcds/6A5): Lockheed Martin Aeronautics Company; names 8 of 8 models: 1049G-82, 1049C-55, 1049E-55, 1049F-55 (USAF C-121C), 1049D-55, 1049B-55 (Navy R7V-1), 1049H-82, 1049-54
- [TCDS A-763](https://openairdocs.org/tcds/A-763): Lockheed Martin Aeronautics Company; names 6 of 6 models: 149-46, 649-79, 749A-79, 749-79, 649A-79, 49-46

## 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 49-46](https://openairdocs.org/model/lockheed-49-46): 1 aircraft (airframe model)
- [Lockheed 749-79](https://openairdocs.org/model/lockheed-749-79): 1 aircraft (airframe model)
- [Lockheed 1049H-82](https://openairdocs.org/model/lockheed-1049h-82): 1 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/56-16-02/models.md
Every aircraft: https://openairdocs.org/ad/56-16-02/aircraft.md

Its text cites no advisory circulars or STCs.

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