AD 56-03-03
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 starting at the wing centerline attaching bolt hole in the wing rear spar junction fittings (P/N 145-14070) at wing Station O have been found on a number of Navion aircraft.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect all Navions for cracks as soon as practicable but not later than May 1, 1956. If no cracks are found, install 3/16-inch thick 1010 steel end plates prior to the next 50 hours of flight time. If cracks are found, stop-drill them with a No. 60 drill (0.040 inch) and install the end plates prior to the next flight.
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 May 1, 1956
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
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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