| AD Number | 47-21-07 | Status | Active |
| Effective Date | Not specified | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | N/A |
| Product Type | ["Aircraft"] | Product Subtype | ["Small Airplane"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Sierra Hotel Aero, Inc. |
| Model(s) | Navion (Army L-17A) |
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.)