AD 55-11-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | DC-6 | Airworthiness Directives; DOUGLAS All DC-6, DC-6A, DC-6B and DC-7 |
| aircraft | The Boeing Company | DC-6A | Airworthiness Directives; DOUGLAS All DC-6, DC-6A, DC-6B and DC-7 |
| aircraft | The Boeing Company | DC-6B | Airworthiness Directives; DOUGLAS All DC-6, DC-6A, DC-6B and DC-7 |
| aircraft | The Boeing Company | DC-7 | Airworthiness Directives; DOUGLAS All DC-6, DC-6A, DC-6B and DC-7 |
| aircraft | The Boeing Company | DC-7B | Airworthiness Directives; DOUGLAS All DC-6, DC-6A, DC-6B and DC-7 |
| aircraft | The Boeing Company | DC-7C | Airworthiness Directives; DOUGLAS All DC-6, DC-6A, DC-6B and DC-7 |
Unsafe Condition
Failure at the end fitting of nose gear yoke P/N 5488450 on DC-7 and P/N 524570 on DC-6 due to fatigue cracks, leading to nose landing gear collapse.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect bolt holes and radii of nose gear yoke for cracks using dye penetrant; replace cracked parts with specified new parts (P/N 5538558 for DC-6, P/N 5538557-1 for DC-7/DC-7B) or rework old parts by remachining and shotpeening. Continue inspections every 500 hours of operation until replaced.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Inspections must be accomplished at intervals not to exceed 500 hours of operation
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Douglas DC-6, DC-6A through Fuselage No. 543; DC-6B through Fuselage No. 590; DC-7 through Fuselage No. 566 (except 486); and C-18A Serial No. 42881 (Fuselage No. 29)
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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