# AD 50-46-01: Oil Tank Standpipe

- 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- Superseded by: Nothing supersedes this AD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/6B1B4C66FF83FB92862569BC00616E50.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/50-46-01

## The airworthiness directive

50-46-01 DOUGLAS: Applies to All Models DC3 and C-47 Series Aircraft Which Utilize a Standpipe in the Engine Oil Tank for Propeller Feathering Oil Reserve.

Compliance required not later than the first engine change after December 1, 1950.

There have been several cases of inability to feather the propeller due to inadequate feathering oil supply, following loss of engine oil. To correct this condition ascertain the quantity of oil retained in the tank by the propeller feathering standpipe with the airplane in the level flight attitude. If the quantity so retained is less than 1 1/2 gallons, rework the standpipe so that at least this quantity is retained.

Aircraft employing C-47 type oil tanks, Douglas P/N 5110511 with Douglas P/N 1355088 standpipe will be considered satisfactory.

## 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/50-46-01/models.md
Every aircraft: https://openairdocs.org/ad/50-46-01/aircraft.md

Its text cites no advisory circulars or STCs.

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