# AD 55-17-01: Flap Torque Tube Bolts

- 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, 149-46, 49-46, 649-79, 649A-79, 749-79 and 1 more
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 2 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1D14A521D81B3C488625696D0071AB87.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/55-17-01

## The airworthiness directive

55-17-01 LOCKHEED: Applies to All Models 49, 149, 649, 749, and 1049 Airplanes.

Compliance required by December 1, 1955, unless already accomplished.

A recent failure of wing flap torque tube assembly, P/N 326605-3, on a Model 1049C is attributed to a defective bolt, P/N AN 23-19. Initial overtorque of the bolt is suspected as the cause of failure of the bolt. It is therefore necessary that all Constellation and Super Constellation airplanes be inspected to ascertain proper installation of bolts, including bolt torque, on all wing flap torque tubes.

Proper torque value for the AN 23-19 bolts is 10 to 20 inch-pounds. Nut torque must be checked with a torque wrench and all overtorqued bolts replaced. If necessary, the next size longer bolt (P/N AN23-20) may be used to facilitate installation within proper torque tolerances. Washers may be used as required, but not to exceed two under the head or two under the nut, to prevent the nut from bottoming on the shank.

## 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 7 of 8 models: 1049G-82, 1049C-55, 1049E-55, 1049F-55 (USAF C-121C), 1049D-55, 1049B-55 (Navy R7V-1), 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: 2 (2 by airframe model, 0 by engine model)
- Makers: Lockheed 2

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)

All 2 models: https://openairdocs.org/ad/55-17-01/models.md
Every aircraft: https://openairdocs.org/ad/55-17-01/aircraft.md

Its text cites no advisory circulars or STCs.

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