# AD 47-02-01: Exhaust Collector Rings

- 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- Superseded by: Nothing supersedes this AD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/0F8B55FBF7C19863862568330051135D.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-02-01

## The airworthiness directive

47-02-01 DOUGLAS: (Was Mandatory Note 9 of AD-762-7.) Applies to C-54 and DC-4 Aircraft.

To be accomplished at next engine change.

Replace present low carbon steel bolts and brass nuts on exhaust collector rings with stainless steel bolts and nuts. This change is necessary in order to eliminate stretching of these bolts, corrosion, and other maintenance problems connected with the present type bolts used in the exhaust collector system.

(Douglas Service Bulletin DC-4 No. 10 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/47-02-01/models.md
Every aircraft: https://openairdocs.org/ad/47-02-01/aircraft.md

Its text cites no advisory circulars or STCs.

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