55-09-04 HAMILTON STANDARD: Applies to All 24260 Propeller Hub Barrels Used on Boeing 377 Aircraft.
Compliance required as indicated.
As a result of cracks occurring in several 24260 hubs when installed as noted, it is considered desirable to improve the strength characteristics of the hub by reworking and shotpeening the areas subject to such failures. Therefore, in order to minimize the possibility of failures of the nature indicated, accomplish the following:
Inspection. Inspect at every overhaul
Rework. Rework hubs at the earliest opportunity, but not later than at the next overhaul following June 15, 1955, for hubs with 6,000 or more hours of total operating time.
(Hamilton Standard Service Bulletin No. 327 dated November 18, 1954, outlines the required rework.)