SESENICH PROPELLERS.

TM 55-4920-201-14

4-25. Model 2A36 - (Complete Assembly. (See

c. Install rear bushing (3), knurled hub up-

figure 4-8.)

ward, on balancing arbor (5) so that top surface of

a. Install screw plug (2) and retaining ring in

bushing aligns with 15-inch line on arbor scale (6).

flange adapter (3).

Secure bushing in this position by tightening

b. Install flange adapter (3) on flange of

bushing setscrew (4) with l/8-inch hex wrench (8,

propeller assembly (1), with adapter pilot diameter

figure 1-13).

seated in center pilot bore (12) of propeller

d. Install arbor downward through propeller

mounting flange. Secure adapter with two propeller

hub and plate (1, figure 4-13, seating pilot

flange attaching nuts or bolts (11), as applicable,

diameter of rear bushing (3) firmly into center bore

180 degrees apart.

of propeller hub.

c. Place two auxiliary support blocks (2, figure

e. Install all four spacers (7), over lower end of

4-12) on felt tray of 7A050 kit case underneath

arbor. Hold in place.

work stand, as shown in figure 4-12.

d. Walk propeller through and under work

f. Install hand wheel (8) in bottom end of

stand, and center propeller hub under work stand

arbor, and tighten wheel to clamp parts securely

with blade shanks resting on auxiliary support-

together.

blocks.

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

e. Install rear hushing (4, figure 4-8), knurled

figure 1-13) and quick-disconnect coupling (10)

hub upward, on balancing arbor (9) so that top

assembly on suspension rod at top end of arbor, and

surface of bushing aligns with the 16 inch posi-

engage suspension cable in lifting plate of hydraulic

tion on arbor scale (6). Lock bushing securely

pump assembly.

in this position by tightening bushing setscrew

h. Hoist entire assembly approximately 1/4

(5) with l/8 inch hex wrench (8, figure 1-13).

inch off work stand. Check to insure that the

suspended assembly is free from interference with

f. Install arbor downward through work stand

work stand and other objects, and note balance

casting and into flange adapter (3, figure 4-8).

condition indicated by the black indicator disc at

Screw arbor onto screw plug (2) until firmly

the top end of the arbor.

bottomed in flange adapter (3).

g. Install adjustable weight (10), grooved end

i. For balance tolerance and application of

downward, over top of balancing arbor, seating

balance corrections, refer to applicable propeller

weight on top surface of rear bushing (4).

manual.

h. Install weight assembly (7). retaining ring

4-28. HELICOPTER APPLICATIONS.

upward, making certain it is fully seated on top end

of arbor. Counterweight (8, figure 4-8) is not used

NOTE

in this application.

All kit components provide for close

i. Install 3/16-inch suspension cable (13,

tolerance slip fits. Clean all mating surfaces

figure 1-13) and quick-disconnect coupling (10)

thoroughly before each kit component

assembly on suspension rod at top end of arbor, and

installation. Avoid nicks, burrs, sharp

engage suspension cable in lifting plate of hydraulic

edges, dirt and other superficial defects.

pump assembly.

Equipment being balanced shall also be

j. Hoist entire assembly approximately 1/4 inch

clean and free from defects. The im-

off auxiliary support blocks. Check to insure that

portance of having all equipment clean and

the suspended assembly is free from interference

devoid of surface defects cannot be over-

with blocks, work stand, and other objects, and

emphasized.

note the balance condition indicated by the black

indicator disc at the top end of the arbor.

4-29. BELL HELICOPTERS.

k. For balance tolerance and application of

4-30. OH-13 and TH-13 Helicopters.

balance corrections, refer to applicable propeller

manual. (Refer to appendix A.)

4-31. OH-13 and TH-13 Engine Fan Assembly

Balance Check. (See figure 4-14.)

4-26. SESENICH PROPELLERS.

a. Install pilot bushing (1), flange upward,

4-27. Model M-76-One Piece Fired Pitch

on balancing arbor (6) so that inner top surface of

(See figure 4-13.)

bushing aligns with 63/4 inch position on arbor scale

a. Center plate (1) on stand table assembly (1,

(7). Lock bushing in this position by moderate and

figure 1-13).

uniform tightening of two bushing setscrews (2),

b. Center propeller assembly (2, figure 4-13,

using 3/32-inch hex wrench (2, figure l-18).

front face downward on plate (1).

Change 1 4-21