# AD 51-02-01: Ramp Type Door Rework

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC3-G102, DC3-G102A, DC3-G103A, DC3-G202A, DC3A-S1C3G, DC3A-S1CG, DC3A-S4C4G, DC3A-SC3G, DC3A-SCG, DC3C-R-1830-90C, DC3C-S1C3G, DC3C-S4C4G and 2 more
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 61 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C48BBE1A2505167D862569BC006186AF.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/51-02-01

## The airworthiness directive

51-02-01 DOUGLAS: Applies to All Model DC3 Series Aircraft With Ramp Type Main Entrance Doors Hinged at the Bottom.

Compliance required as indicated below.

  (1) At next No. 1 inspection or equivalent and at regular intervals not to exceed approximately 100 hours, inspect the main entrance door hinges and locking and warning mechanisms for alignment and/or adjustment until the rework of item (2) is accomplished.

  (2) Compliance required by July 1, 1951.

A. Install an inspection window for at least the uppermost main entrance door locking bayonet. The installation to be in a manner to permit visual observation of the bayonets in the locked position so that it can be determined by visual means that the door is properly closed and locked. The bayonets and adjacent structure should also be appropriately marked with a paint stripe to indicate when the bayonets are in the locked position.

B. Provide means to prevent disengagement of bayonets by creeping due to vibration or other loads in flight. A notched bayonet installation similar to that covered in Metropolitan Airparts Service Bulletin No. MAP-1A for their airstairs Model A; or similar to the notched bayonet installation used on the Douglas DC-6 and Super DC3 main entrance doors; or a spring loaded positive over center latching mechanism will be considered to meet this objective.

  (3) Compliance required by January 1, 1953.

To reduce the possibility of inadvertent opening of the door in flight install stops to positively limit the lock mechanism travel in accordance with Metropolitan Airparts Service Bulletins No. MAP-4A, MAP-5A, or MAP-6A (for Model A, C, or D Airstair Doors, respectively) or equivalent.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-669](https://openairdocs.org/tcds/A-669): The Boeing Company; names 10 of 10 models: DC3C-S4C4G, DC3C-R-1830-90C, DC3A-S1C3G, DC3C-SC3G, DC3C-S1C3G, DC3A-SCG, DC3A-SC3G, DC3A-S1CG…
- [TCDS A-618](https://openairdocs.org/tcds/A-618): The Boeing Company; names 4 of 4 models: DC3-G202A, DC3-G102A, DC3-G103A, DC3-G102

## 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: 61 (61 by airframe model, 0 by engine model)
- Makers: Douglas 61

Models with the most aircraft:

- [Douglas DC3C-S1C3G](https://openairdocs.org/model/douglas-dc3c-s1c3g): 30 aircraft (airframe model)
- [Douglas DC3C-R-1830-90C](https://openairdocs.org/model/douglas-dc3c-r-1830-90c): 10 aircraft (airframe model)
- [Douglas DC3-G202A](https://openairdocs.org/model/douglas-dc3-g202a): 7 aircraft (airframe model)
- [Douglas DC-3A-S1C3G](https://openairdocs.org/model/douglas-dc-3a-s1c3g): 5 aircraft (airframe model)
- [Douglas DC3C-S4C4G](https://openairdocs.org/model/douglas-dc3c-s4c4g): 5 aircraft (airframe model)
- [Douglas DC3A-S4C4G](https://openairdocs.org/model/douglas-dc3a-s4c4g): 2 aircraft (airframe model)
- [Douglas DC3-G102A](https://openairdocs.org/model/douglas-dc3-g102a): 1 aircraft (airframe model)
- [Douglas DC3C-SC3G](https://openairdocs.org/model/douglas-dc3c-sc3g): 1 aircraft (airframe model)

All 8 models: https://openairdocs.org/ad/51-02-01/models.md
Every aircraft: https://openairdocs.org/ad/51-02-01/aircraft.md

Its text cites no advisory circulars or STCs.

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