AD 53-15-03

53-15-03 HARTZELL: Applies to All Model HC-82XF-1 Controllable Pitch Propellers Installed on Cessna 180 Aircraft.

Compliance required as indicated.

A number of recent in service failures of the pitch change link screws (P/N A-98) on Hartzell HC-32XF-1 propellers have resulted in exposing the occupants to hazardous situations. All such propeller failures have resulted in forced landings, some of which caused major damage to the aircraft. Due to the serious nature of these failures, the following inspections and replacements are necessary:

I. Inspection. A. Prior to August 1, 1953, visually inspect all link screws to determine: (1) If any are broken. (2) If any are cracked or bent. (3) If any are not fully seated on the conical seat.

B. If any are found broken, cracked, bent or not fully seated on the conical seat, prior to further flight replace with screws as noted in item II.

C. If visual inspection proves satisfactory, the propellermay be flown subject to compliance with item II.

II. Replacement. Compliance required prior to September 1, 1953.

A. Replace all original A-98 link screws with improved A-98-B link screws in accordance with Hartzell Service Bulletin No. 24, dated May 28, 1953.

B. Propeller with serial numbers not listed in Service Bulletin No. 24 may not have the improved screws. Owners of these propellers shall check with the propeller manufacturer for verification.