Chapter 2. OPERATING INSTRUCTIONS - TM-55-1730-208-130009

TM 55-1730-208-13

CHAPTER 2

OPERATING INSTRUCTIONS

Section I. OPERATION UNDER USUAL CONDITIONS

2-7. Operation.

2-1. Erection.

The hydraulic jack may be assembled or changed to any

Operation of the hydraulic jack shall be in accordance

of five basic closed height configurations (see figure 2-

with the following procedures. (See figure 2-1.)

1) by the use of leg extensions and additional braces.

The hydraulic jack may be assembled or changed to a

height of 36, 54, 72, 90, or 108 inches. The following

WARNING

paragraphs describe the procedures required to

Clear area beneath aircraft of

assemble the hydraulic jack into the 36-inch

equipment and personnel before

configuration or alter it to any of the remaining heights.

lowering aircraft.

Stop raising

(See figure 2-1.) Using hydraulic jack erection diagram

operation immediately if a defect

(figure 2-1 ) and information in paragraphs 2-2 through

is noted that could cause danger

2-6 erect hydraulic jack to the desired height.

to personnel or damage to the

equipment

continuing

2-2. Closed Height 36-inch.

operation.

To assemble the hydraulic jack into the 36inch

a. Positioning. The ground surface under the

configuration, three leg assemblies are attached to the

hydraulic jack should be level. If ground surface is soft,

cylinder and ram assembly and a foot assembly is

a board or plank should be placed under each foot

secured to the bottom of each leg. The pump assembly

assembly. The hydraulic jack should be positioned so

is lug-mounted on the lower end of one leg and six no.

that a line drawn through any two of the foot assemblies

1 tripod braces are used.

will be parallel with the aircraft fuselage.

2-3. Closed Height 54-inch.

b. Raising. Raise the hydraulic jack as follows:

(1) Turn extension screw of cylinder and ram

To assemble or change the 36-inch hydraulic jack

assembly out until jack pad socket contacts aircraft jack

into the 54-inch configuration, one leg extension is

pad.

added between each leg and foot assembly of the 36-

inch configuration and six additional no. 2 braces are

CAUTION

added.

Do not extend extension screw of

2-4. Closed Height 72-inch.

ram assembly out more than 18

inches.

To assemble or change the 36-inch hydraulic jack into

the 72-inch configuration, two leg extensions are added

(2) Position pointer of rise indicator rod on

between each leg and foot assembly of the 36-inch

zero line of rise indicator decal.

configuration and six no. 2 and six no. 3 braces are

(3) Loosen retainer screw on ram lock nut

added.

assembly to permit ram lock nut assembly to lower by

its own weight as ram rises.

2-5. Closed Height 90-inch.

(4) Open vent assembly and close release

To assemble or change the 36-inch hydraulic jack into

assembly located on pump assembly.

the 90-inch configuration, three leg extensions are

(5) Disconnect chain to free pump handle and

added between each leg and foot assembly of the 36-

operate pump handle as required to raise aircraft.

inch configuration and six no. 2, no. 3, and no. 4

braces are added.

(6) Tighten ram lock nut assembly against

cylinder and tighten retainer screw.

2-6. Closed Height 108-inch.

(7) Place pump handle in the stowed position

and secure it with the chain.

To assemble or change the 36-inct hydraulic jack into

the 108-inch configuration, four leg extensions are

added between each leg and foot assembly of the 36-

c. Lowering. Lower the hydraulic jack as follows:

inch configuration. Six no. 2, no. 3, no. 4, and no. 5

braces and six brace links are also added.

2-1