AD 53-08-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sierra Hotel Aero, Inc. | Navion (Army L-17A) | Airworthiness Directives; All Navion Models Except Those Incorporating Palo Alto Airport Co. or Symon Engineering Co. Horizontal Stabilizer Modifications |
| aircraft | Sierra Hotel Aero, Inc. | Navion A (Army L-17B and L-17C) | Airworthiness Directives; All Navion Models Except Those Incorporating Palo Alto Airport Co. or Symon Engineering Co. Horizontal Stabilizer Modifications |
| aircraft | Sierra Hotel Aero, Inc. | Navion B | Airworthiness Directives; All Navion Models Except Those Incorporating Palo Alto Airport Co. or Symon Engineering Co. Horizontal Stabilizer Modifications |
Unsafe Condition
Improper rivet edge distance on 145-21404-1 and -2 front fittings of the horizontal stabilizer may result in structural failure due to insufficient material extending beyond the rivet holes.
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Required Actions
Inspect both 145-21404-1 and -2 front fittings for proper rivet edge distance. If the edge distance is less than 1/16 inch, install new fittings with proper edge distance.
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Compliance Time
June 15, 1953, or next 100-hour inspection, whichever is first
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Affected Aircraft
Sierra Hotel Aero, Inc. Navion models (Army L-17A), Navion A (Army L-17B and L-17C), Navion B, except those incorporating Palo Alto Airport Co. or Symon Engineering Co. horizontal stabilizer modifications.
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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