AD 48-25-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | C54-DC | Airworthiness Directives; DOUGLAS All C54-DC and DC-4 Airplanes |
| aircraft | The Boeing Company | DC-4 | Airworthiness Directives; DOUGLAS All C54-DC and DC-4 Airplanes |
Unsafe Condition
Previous fires and the fire hazard in zone 3 necessitate enhancing the fire warning and extinguishing systems in the nacelles of C54-DC and DC-4 airplanes.
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Required Actions
Install seven fire detector units in zone 3 nacelle locations as specified, revise the fire extinguisher system by adding two 15-pound CO2 bottles, and replace aluminum CO2 pipes with steel pipes in specified areas.
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Compliance Time
May 1, 1949
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Affected Aircraft
Douglas C54-DC Series and DC-4 Airplanes prior to serial number 43095, operated in scheduled and nonscheduled air carrier passenger service.
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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