AD 47-21-07

final rule
Data completeness: 60%

Airworthiness Directives; Navion Serial Numbers NAV-4-10 Through 20, 22 Through 26, 28, 29, 31 Through 49, 51, 52, 55 Through 58, 60, 63, 73, 76, 79, 82 Through 84, 88 Through 95, 99 Through 104, 106, 108, 110, 112 Through 116, 120 Through 122, 124, 125, 130, 133, 141, 151, 153, 158, 163, 171.

AD Number
47-21-07
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Sierra Hotel Aero, Inc. Navion (Army L-17A) Airworthiness Directives; Navion Serial Numbers NAV-4-10 Through 20, 22 Through 26, 28, 29, 31 Through 49, 51, 52, 55 Through 58, 60, 63, 73, 76, 79, 82 Through 84, 88 Through 95, 99 Through 104, 106, 108, 110, 112 Through 116, 120 Through 122, 124, 125, 130, 133, 141, 151, 153, 158, 163, 171.

Unsafe Condition

The cork or rubber filler strip cemented to the upper surface of the 145-42201-71 carburetor air intake scoop may become dislodged and drawn into the air induction system.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Replace the filler strip with a 3 1/8-inch x 5/8-inch dural strip of 0.093-inch thickness, flush-riveted to the scoop.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

prior to August 1, 1947

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) serial numbers NAV-4-10 Through 20, 22 Through 26, 28, 29, 31 Through 49, 51, 52, 55 Through 58, 60, 63, 73, 76, 79, 82 Through 84, 88 Through 95, 99 Through 104, 106, 108, 110, 112 Through 116, 120 Through 122, 124, 125, 130, 133, 141, 151, 153, 158, 163, 171.

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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