AD 47-27-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | C54-DC | DOUGLAS Model C-54 and DC-4 Series Airplanes |
| aircraft | The Boeing Company | C54A-DC | DOUGLAS Model C-54 and DC-4 Series Airplanes |
| aircraft | The Boeing Company | C54B-DC | DOUGLAS Model C-54 and DC-4 Series Airplanes |
| aircraft | The Boeing Company | C54D-DC | DOUGLAS Model C-54 and DC-4 Series Airplanes |
| aircraft | The Boeing Company | C54E-DC | DOUGLAS Model C-54 and DC-4 Series Airplanes |
| aircraft | The Boeing Company | C54G-DC | DOUGLAS Model C-54 and DC-4 Series Airplanes |
| aircraft | The Boeing Company | DC-4 | DOUGLAS Model C-54 and DC-4 Series Airplanes |
Unsafe Condition
Cracking failure of the collector ring 'Y' outlet assembly due to breathing of the exhaust stack, which induces failure creating a fire hazard.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Weld a scalloped stiffener flange on the exhaust collector aft of the 'Y' outlet assembly. Inspect for cracks immediately and at intervals not exceeding 50 hours of operation until the repair is completed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Not later than the first engine change subsequent to July 15, 1947, but in any event not later than October 15, 1947.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
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.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.