58-03-02 HAMILTON STANDARD: Applies to All Hamilton Standard 4U18 and 5U18 Governors Shipped From the Factory Prior to September 26, 1957.
Compliance required:
A. Prior to April 15, 1958, for governors with the solenoid valve installed with the solenoid-electrical connection combination parallel to the governor drive shaft axis (Position 1 as shown in Hamilton Standard Service Bulletins Nos. 528, 536, and 536A).
B. At next governor overhaul for governors with the solenoid valve installed with the solenoid-electrical connection combination at right angles to the governor drive shaft axis (Positions 2 and 4 as shown in Hamilton Standard Service Bulletins Nos. 528, 536 and 536A).
Three unwanted propeller reversals have been reported. Investigation revealed that, in two cases, the oil hole sealing plugs in the governor body solenoid valve boss were missing. In the third case, oil leaked past one of the oil hole sealing plugs.
To preclude additional unwanted reversals from this cause, remove the solenoid valve assembly from the governor. Inspect for the presence of two oil hole plugs, PN 68753, in two- flyweight-type governor bodies and one oil hole plug, P/N 321736, in four-flyweight-type governor bodies. Install plugs as required. Install solenoid valve mounting gasket, P/N 60912, reworked to solenoid mounting gasket P/N 322778, such that the triangular cutout is position over the two plugged holes (two-flyweight-type) or over the single-plugged hole (four-flyweight- type). As an alternative, particularly on earlier models not incorporating the second drain passage as described in Service Bulletins Nos. 345, and 345A, install solenoid valve mounting gasket, P/N 60912, reworked to solenoid mounting gasket, P/N 322779, by making two cuts at each corner and removing each cutout portion. Identify inspected and/or reworked governors by any convenient means. In lieu of replacing the P/N 60912 gaskets, the control body solenoid may be permanentlyvented by milling grooved channels in the boss face in accordance with Hamilton Standard Service Bulletin No. 536B.
Governors which were shipped from the factory September 26, 1957, and later, are identified by Serial Number WH87433 and above. Likewise, those governors with Serial Numbers below WH87433, but having an inspector's stamp in white ink located to the left of Hamilton Standard nameplate, were also shipped from the factory September 26, 1957, or later. The stamping consists of an oval enclosing a two-letter initial. Controls so identified need not be inspected for inclusion of the sealing plugs, but must have the gasket reworked.
(Hamilton Standard Service Bulletins Nos. 528, 536, 536A, and 536B cover this same subject.)