- Models
- C54-DC, C54A-DC, C54B-DC, C54D-DC, C54E-DC, C54G-DC, DC-4
- Data sheet
- TCDSA-762
- Registered aircraft
- 4 matched by model
- Product
- Aircraft · Large airplane
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| FAA DRS HTML | 20 KB | 67158e9a…ba554f7 | FAA DRS (API key needed) |
On this page
The airworthiness directive
47-27-04 DOUGLAS: (Was Mandatory Note 18 of AD-762-7.) Applies to All C-54 and DC-4 Series Airplanes Having Exhaust Collector Rings Made Up of Top Segments P/N 5174842-56 L.H. and 5174529-56 R.H.
To be accomplished not later than the first engine change subsequent to July 15, 1947, but in any event not later than October 15, 1947.
Several reports have been received of cracking failure of the collector ring "Y" outlet assembly due to breathing of the exhaust stack. This induces failure which creates a fire hazard. This type of exhaust collector "Y" is not reinforced with a flange and is shown on page 4, Douglas Service Bulletin No. DC-4 No. 31. To correct this condition weld a scalloped stiffener flange on the exhaust collector aft of the "Y" outlet assembly.
(Douglas Service Bulletin No. DC-4 No. 68 covers this same subject.)
Until this repair is accomplished, inspection for cracks should be made immediately and at periods not to exceed 50 hours of operation.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 4
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.