# AD 57-03-02: Fuel Strainer Screen

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC-7, DC-7B, DC-7C, 1049-54, 1049B-55 (Navy R7V-1), 1049C-55, 1049D-55, 1049E-55, 1049F-55 (USAF C-121C), 1049G-82, 1049H-82, 149-46 and 6 more
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 9 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/BDA7BD8F6E72EC7D8625696D00719C00.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/57-03-02

## The airworthiness directive

57-03-02 DOUGLAS AND LOCKHEED: Applies to Lockheed Constellation Series Airplanes and Douglas DC-7 Series Airplanes With Wright Engines.

Compliance required not later than December 1, 1957.

Under certain cold weather operating conditions it is possible for the fuel inlet strainer and other parts in the engine master control to become clogged with ice as a result of entrained water in the fuel freezing on the screen. This has caused a loss of power on all engines simultaneously.

To relieve strainer icing, a screen having a bypass valve Bendix P/N 366204 should be installed in replacement of the screen not having a bypass valve. Bendix Service Bulletin No. 797 covers this subject. It should be noted that the incorporation of the screen with bypass will not positively prevent power loss from fuel ice; therefore, work is continuing to develop a means to protect other portions of the master control downstream of the inlet strainer. If necessary, a supplement to this notewill be published when additional information becomes available.

## Affected data sheets (4) (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
- [TCDS 4A10](https://openairdocs.org/tcds/4A10): The Boeing Company; names 3 of 3 models: DC-7, DC-7C, DC-7B
- [TCDS 4A17](https://openairdocs.org/tcds/4A17): Lockheed Martin Aeronautics Company; names 1 of 1 models: 1649A-98

## 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: 9 (9 by airframe model, 0 by engine model)
- Makers: Douglas 5, Lockheed 4

Models with the most aircraft:

- [Douglas DC-7](https://openairdocs.org/model/douglas-dc-7): 2 aircraft (airframe model)
- [Douglas DC-7B](https://openairdocs.org/model/douglas-dc-7b): 2 aircraft (airframe model)
- [Douglas DC-7C](https://openairdocs.org/model/douglas-dc-7c): 1 aircraft (airframe model)
- [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)
- [Lockheed 1649A-98](https://openairdocs.org/model/lockheed-1649a-98): 1 aircraft (airframe model)

All 7 models: https://openairdocs.org/ad/57-03-02/models.md
Every aircraft: https://openairdocs.org/ad/57-03-02/aircraft.md

Its text cites no advisory circulars or STCs.

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