# AD 48-48-02: Vacuum Pump Line Replacement

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC-6, DC-6A and DC-6B
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 17 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F7D983447BA772E2862569BC005AA751.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/48-48-02

## The airworthiness directive

48-48-02 DOUGLAS: Applies to All DC-6 Aircraft Not Equipped With Steel Vacuum Pump Discharge Lines Aft of the Firewall and Chicago Metal Hose Assemblies From the Oil Separator to the Pesco Pump.

To be accomplished as soon as practicable, but not later than May 1, 1949.

In cases of malfunctioning of vacuum pumps or other vacuum pump system components, fire can occur within the lines and burn through the hose connection into the engine compartment. To prevent such occurrences, replace the present Aeroquip Hose P/N 260-10WD-15 1/2, existing between oil separator and Pesco vacuum pump, with a new Chicago Metal Hose Assembly No. 9273-1.

(Douglas Service Bulletin No. 383 covers this same subject.) Also, to prevent fire from entering the zone behind the firewall, replace the dural vacuum pump discharge line, aft of the firewall, with a steel line.

(Douglas Service Bulletin DC-6 No. 401 covers this same subject.)

## Affected data sheets (3) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 6A3](https://openairdocs.org/tcds/6A3): The Boeing Company; names 1 of 3 models: DC-6A
- [TCDS 6A4](https://openairdocs.org/tcds/6A4): The Boeing Company; names 1 of 2 models: DC-6B
- [TCDS A-781](https://openairdocs.org/tcds/A-781): The Boeing Company; names 1 of 1 models: DC-6

## 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: 17 (17 by airframe model, 0 by engine model)
- Makers: Douglas 17

Models with the most aircraft:

- [Douglas DC-6B](https://openairdocs.org/model/douglas-dc-6b): 9 aircraft (airframe model)
- [Douglas DC-6A](https://openairdocs.org/model/douglas-dc-6a): 7 aircraft (airframe model)
- [Douglas DC-6](https://openairdocs.org/model/douglas-dc-6): 1 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/48-48-02/models.md
Every aircraft: https://openairdocs.org/ad/48-48-02/aircraft.md

Its text cites no advisory circulars or STCs.

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