59-01-03 HARTZELL: Applies to HC-12X20, HC-13X20, HC-82X and HC-83X Series Propellers With Hub Serial Numbers As Indicated Herein.
Compliance required as indicated.
To minimize the possibility of failure of the split rings used to retain the blades in the hub, replace (if not previously accomplished) all unmarked split rings with new split rings marked with the letter "N", as follows:
(1) Prior to February 15, 1959.
HUB MODEL
HUB SERIAL NO. INCLUSIVE
HC-82XF-1DB, -1BB
T-913 to T-2891
HC-82XF-2B
F-400 to F-1675
(2) Prior to April 15, 1959.
HUB MODEL
HUB SERIAL NO. INCLUSIVE
HC-82X20-1B
C-104 to C-267
HC-12X20-7D, 7C, 7E
R-118 to R-260
HC-12X20-8D, 3C, 3E
P-157 to P-494
HC-83X20-2C
D-448 to D-1530
HC-83XF-2A
U-105 to U-437
HC-83X20-2CL
V-104 to V-179
HC-13X20-6L
X-101 to X-111
(3) Prior to June 1, 1959.
HUB MODEL
HUB SERIAL NO. INCLUSIVE
HC-82XG-1D
G-102 to G-305
HC-82XG-2B
K-592 to K-2919
HC-82XL-1D100-Y to 121-Y
HC-82XG-6B
100D to 169D
After compliance, stamp the letter "N" after the hub serial number. This letter "N" should be stamped on propellers already modified. Serial numbers of propellers modified at the factory are listed in Hartzell Bulletin No. 64. The aircraft log book should contain this information for propellers modified in the field.
(Hartzell Bulletin No. 64 covers this same subject.)