| AD Number | 47-11-02 | 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) |
47-11-02 NAVION: (Was Mandatory note 2 of AD-782-3.) Applies to All Models Equipped With Hartzell HC12x20-1 Propeller Hubs and 8628 Blades.
To be accomplished not later than May 1, 1947.
Vibration tests of the Hartzell HC12x20-1 propeller with these airplanes indicate that the propeller diameter should be reduced from 86 inches to 84 inches. This is accomplished by cutting 1 inch from the tip of each 8628 blade, and making the shortened blade 18428R. This blade rework must be performed either by the Hartzell factory or by a certified propeller repair agency.
(Par. B of North American Field Service Bulletin No. 20 dated January 28, 1947, covers this rework.)
Upon compliance with this AD, the presently required placard against engine operation between 1,950 and 2,150 r.p.m. and over 2,250 r.p.m. may be removed.