AD 49-46-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | DC-4 | Airworthiness Directives; DOUGLAS All Models DC-4 AND DC-6 Aircraft |
| aircraft | The Boeing Company | DC-6 | Airworthiness Directives; DOUGLAS All Models DC-4 AND DC-6 Aircraft |
| aircraft | The Boeing Company | DC-6A | Airworthiness Directives; DOUGLAS All Models DC-4 AND DC-6 Aircraft |
| aircraft | The Boeing Company | DC-6B | Airworthiness Directives; DOUGLAS All Models DC-4 AND DC-6 Aircraft |
Unsafe Condition
Excessive air temperatures in the vacuum system discharge line could damage nacelle components or cause system failure.
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Required Actions
Install a fusible plug with specified AN fittings and metal composition in the vacuum pump discharger port, or replace the oil separator with Genisco No. 40081 or equivalent. Incorporate an overboard drain line if using the fusible plug modification.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
not later than April 1, 1950
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Affected Aircraft
Douglas DC-4, DC-6, DC-6A, DC-6B aircraft equipped with vacuum systems using oil separators other than the type mentioned in Item 2.
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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