58-24-01 HAMILTON STANDARD: Applies to All 2H17K3, 2H17U3, 2H17AA3 and 2H17AC3 Hollow Steel Propeller Blades.
Compliance required as indicated.
It has been determined that 2H17K3, 2H17U3, and 2H17AA3 blades have a substantial reduction in fatigue resistance after 5,000 hours' operational time. The 2H17AC3 blades have shown no reduction in fatigue resistance at 5,400 hours' operational time, but the limited number of blades in service does not warrant continued sampling inspection. Therefore, these blades must be removed from service, as follows:
1. 2H17K3, 2H17U3, and 2H17AA3 blades when they have accumulated 5,000 operational hours.
2. 2H17AC3 blades when they have accumulated 5,400 operational hours.
(Hamilton Standard Service Bulletins Nos. 305 and 559 cover this same subject.)
This supersedes AD 54-23-03.