AD 55-09-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | DC-6 | Airworthiness Directives; DOUGLAS All DC-6 Series Aircraft |
| aircraft | The Boeing Company | DC-6A | Airworthiness Directives; DOUGLAS All DC-6 Series Aircraft |
| aircraft | The Boeing Company | DC-6B | Airworthiness Directives; DOUGLAS All DC-6 Series Aircraft |
Unsafe Condition
Loss of manual r.p.m. control can occur as a result of tripping of the fast-acting magnetic circuit breaker before the slow-acting fuse is blown on a faulted branch.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the 'Manual' 10-ampere magnetic circuit breaker with a 5-ampere thermal type breaker and replace the four 5-ampere fuses in the synchronizer unit with 2-ampere Slo-Blo fuses.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
as soon as practicable but not later than August 1, 1955
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Affected Aircraft
All DC-6 Series Aircraft Incorporating Hamilton Standard Propellers Prior to Serial No. 473
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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