AD 47-12-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | C54-DC | DOUGLAS Model DC-4 and C-54 Series Airplanes |
| aircraft | The Boeing Company | C54A-DC | DOUGLAS Model DC-4 and C-54 Series Airplanes |
| aircraft | The Boeing Company | C54B-DC | DOUGLAS Model DC-4 and C-54 Series Airplanes |
| aircraft | The Boeing Company | C54D-DC | DOUGLAS Model DC-4 and C-54 Series Airplanes |
| aircraft | The Boeing Company | C54E-DC | DOUGLAS Model DC-4 and C-54 Series Airplanes |
| aircraft | The Boeing Company | C54G-DC | DOUGLAS Model DC-4 and C-54 Series Airplanes |
| aircraft | The Boeing Company | DC-4 | DOUGLAS Model DC-4 and C-54 Series Airplanes |
Unsafe Condition
Center main bearing failures have occurred in Pratt & Whitney R-2000-11 engines, specifically involving roller bearing P/N 24966 and plain bearings P/N 97387 and 97387B.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove plain type center main bearings (P/N 97387 and 97387B) from service by July 15, 1947. Install superinspected roller bearings (P/N 24966) or incorporate 2SD13-G or equivalent main components of the power section crankcase. Conduct main oil screen checks at each routine inspection or every 75 hours of operation until modifications are complete.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
not later than July 15, 1947
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Affected Aircraft
Douglas Model DC-4 and C-54 Series airplanes equipped with Pratt & Whitney R-2000-11 engines
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
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