AD 55-01-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sierra Hotel Aero, Inc. | Navion (Army L-17A) | Airworthiness Directives; Navion All Models |
| aircraft | Sierra Hotel Aero, Inc. | Navion A (Army L-17B and L-17C) | Airworthiness Directives; Navion All Models |
| aircraft | Sierra Hotel Aero, Inc. | Navion B | Airworthiness Directives; Navion All Models |
Unsafe Condition
Cracks in fuselage frame 143-31004-16 at Station 294.1 inboard from the top stringer cutout at W.L. 21.00.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect for cracks as soon as practicable but not later than March 15, 1955. If cracks are present, determine if they have extended beyond the critical rivet. Apply interim repair (stopdrilling, relocating rivets, installing gussets) or permanent repair (replacing frame, modifying stringers, installing patches) based on crack extent. Conduct 100-hour inspections until reinforcement is completed.
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 March 15, 1955
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sierra Hotel Aero, Inc. Navion (Army L-17A), Navion A (Army L-17B and L-17C), Navion B models, all serial numbers.
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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