SIKORSKY HELICOPTERS

TM 55-4920-201-14

4-51. SIKORSKY HELICOPTERS,

4-52. UH-19 Helicopter.

4-53. UH-19 (Except Series C) Engine Fan

Assembly Balance Check. (See figure 4-31.

a. Center engine fan assembly (1), with

shroud upward, on stand table assembly (1, figure

1-13).

b. Install cone (2, figure 4-31) hub upward,

on balancing arbor (3) so that top surface of cone

hub aligns with 12--inch position on arbor scale

(4). Secure cone in this position by tightening cone

setscrew (5) with t/s-inch hex wrench (8, figure 1-

13).

C. Install arbor downward through fan

assembly hub, seating bottom surface of cone (2,

figure 4-31) in approximate center and on top of

the fan assembly hub.

d. Install plate (6), hub downward, over

bottom end of arbor. Seat pilot lip on top surface of

plate firmly and squarely over pilot diameter on

bottom surface of fan assembly hub. Do not tighten

plate hub setscrew.

e. Install spacers (7) on arbor under plate (6)

hub.

f. Install hand wheel (26, figure 1-13) in

bottom of arbor, and tighten wheel to clamp

spacers, plate fan assembly hub, and top cone

securely together.

g. Install 3 / 16-inch suspension cable (13)

and quick-disconnect coupling (10) assembly on

suspension rod at top end of arbor, and engage

suspension cable in lifting plate of hydraulic pump

assembly.

1. Fixture (2337, 7HEL054

h. Hoist entire assembly approximately

kit)

inch off work stand. Check to insure that

2. Rotor assembly

suspended assembly is free from interference with

3. Balancing arbor (2259,

work stand and other objects, and note the balance

7A050 kit)

4. Arbor scale

condition indicated by black indicator disc at top

5. Spacer (7A050 kit)

end of the arbor.

i. For balance tolerance and application of

Figure 4,-30. Balancer Installation - OH-23

Helicopter Main Rotor Head and

balance corrections, refer to applicable helicopter

Control Rotor Assembly.

manual. (Refer to appendix A.)

4-51