# AD 47-42-14: Voltage Regulator Bearings

- 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- Superseded by: Nothing supersedes this AD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/525F66403AC3DD85862569BC004A22CB.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-42-14

## The airworthiness directive

47-42-14 DOUGLAS: (Was Mandatory Note 11 of AD-781-1.) Applies to DC-6 Serial Numbers 42854 to 42880, Inclusive; 42882 to 42884, Inclusive; 43000 and 43001.

To be accomplished not later than first blower overhaul after January 1, 1948.

To prevent bearing failures in the voltage regulator blowers, replace the bearings formerly packed with lubricant Z815 with new bearings containing lubricant Z801.

(Douglas Service Bulletin DC-6 No. 43 describes the complete rework.)

## 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/47-42-14/models.md
Every aircraft: https://openairdocs.org/ad/47-42-14/aircraft.md

Its text cites no advisory circulars or STCs.

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