| AD Number | 58-04-02 | Status | Active |
| Effective Date | Not specified | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | N/A |
| Product Type | ["Propeller"] | Product Subtype | Not specified |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Hartzell Propeller, Inc. |
| Model(s) | HC-93Z20-2 |
58-04-02 HARTZELL: Applies to All HC-93Z20-2C and -2B Propellers. The -2C Propellers Are Installed on All Beech E50 and F50 Aircraft, and -2B Propellers Are Installed on Some Cessna T-50 With Lycoming R-680 Engines and on Mansdorf Conversion of Grumman G- 44 With Lycoming R-680 Engines (STC SA4-2).
Compliance required prior to next flight for propellers with hub Serial Numbers 100A through 361A and above.
The recent failure of an A-1307 split ring, which the records show had less than 180 hours' operating time, permitted the propeller blade to leave the hub. In order to minimize the possibility of the occurrence of this type of serious failure, the present split ring must be replaced with a strengthened split ring. Accordingly, replace A-1307 split ring with A-1331 split ring. This also requires replacing A-1303 bearing with A-1303A bearing. Modified propellers should be stamped HC-93Z20-2B1 or -2C1. New propellers so stamped will incorporate modified split rings and bearings.
(Hartzell Service Bulletin No. 55 covers this same subject.)