# AD 48-17-04: Vacuum Pumps

- Type: Airworthiness directive
- Status: Current
- Products: Boeing C54-DC, C54A-DC, C54B-DC, C54D-DC, C54E-DC, C54G-DC and DC-4
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 4 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/37D70EF064B360AF862569BC005A666C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/48-17-04

## The airworthiness directive

48-17-04 DOUGLAS: Applies to All DC-4 and C-54 Aircraft Equipped With Pesco Vacuum Pumps and Separators.

To be accomplished not later than the date established in accordance with the provisions of special Civil Air Regulation Serial Number SR-329, or any subsequent regulation affecting this compliance date.

In case of malfunctioning of vacuum pumps or other vacuum pump system components, fire can occur within the lines and burn through the hose connections into the engine compartment. To prevent such occurrences a hose liner must be installed between the exhaust port vacuum pump fittings and the separator line or a stainless steel flexible hose must be installed between the pump and the separator.

(Douglas Service Bulletin DC-4 No. 85 as revised March 10, 1948, covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-762](https://openairdocs.org/tcds/A-762): The Boeing Company; names 7 of 7 models: C54E-DC, C54G-DC, C54B-DC, DC-4, C54A-DC, C54D-DC, C54-DC

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

Models with the most aircraft:

- [Douglas C54D-DC](https://openairdocs.org/model/douglas-c54d-dc): 2 aircraft (airframe model)
- [Douglas C54E-DC](https://openairdocs.org/model/douglas-c54e-dc): 1 aircraft (airframe model)
- [Douglas C54G-DC](https://openairdocs.org/model/douglas-c54g-dc): 1 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/48-17-04/models.md
Every aircraft: https://openairdocs.org/ad/48-17-04/aircraft.md

Its text cites no advisory circulars or STCs.

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