47-21-07: Carburetor Air Intake Scoop Filler Strip
FAA order 47-21-07 is an airworthiness directive. The FAA's subject line: Carburetor Air Intake Scoop Filler Strip. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Sierra Hotel Aero, Inc.
- Models
- Navion (Army L-17A)
Dates and paperwork
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (850 characters)
47-21-07 NAVION: (Was Mandatory Note of AD-782-3.) Applies to 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.
To be accomplished prior to August 1, 1947.
Some airplanes were delivered with a cork or rubber filler strip cemented to the upper surface of the 145-42201-71 carburetor air intake scoop where the scoop fits over the flange of the air mixing chamber. This strip may becomes dislodged and drawn into the air induction system. To prevent this, 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.
(NAA Field Service Bulletin No. 15 covers this subject.)
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/47-21-07.json · aircraft systems.