Section II. ALIGNMENT AND BORESIGHTING PROCEDURES

TM 9-1270-212-14&P

Section II. ALIGNMENT AND BORESIGHTING PROCEDURES

4-3. Scope.

c. Remove the fairing covering the TSU mounting pad

located on the TSU upper turret support assembly.

The procedures in this section establish the requirements

d. Place the TSU boresight device onto the TSU

for aligning and boresighting the helmet-directed fire

control sub system (HSS) to the telescopic sight unit (TSU)

reference pads (fig. 4-3) and lock into place with the screw

for XM128, AH-l S (Mod) and XM136, AH-l S .

fastener.

For boresighting procedures for XM 136, AH-1S

NOTE

, refer to TM9-1090-206-30, Aviation Inter-

and

mediate Maintenance Manual for Armament Subsystem,

Do not remove or adjust the factory-set TSU

Helicopter: 20-mm Automtitic Gun, XM97E1/E2.

reference pads.

4-4. Alignment Preparation.

e. Using a steel tape, measure 1000 6 inches (83 feet 4

inches, 6 inches) in front of the TSU from the plumb

Prepare for the system alignment by performing the

mark directly below the pivot point of the TSU.

procedures listed in the following paragraphs:

NOTE

a. Position the fairly leveled helicopter in an area that

will accommodate the equipment, as shown in figure 4-2.

Technicians should now assume the gunner's

and pilot's positions and remain there for the

remainder of the alignment and boresighting.

Do not lean on or stand on the aircraft skids

during this operation.

Place the center target assembly (foldout FO-11

sheet 3) forward of the helicopter and at a distance of 1000

6 inches (83 feet 4 inches, 6 inches), keeping the target

perpendicular to the imaginary centerline of the helicopter

as much as possible on initial placement.

g. Place the borescope in the center hole of the TSU

boresight device. Sight through the borescope at the TSU

boresight device target.

h. With the assistance of a second person to move the

center target assembly in azimuth and elevation as directed

by the person viewing the target through the borescope,

adjust the center target assembly so that the intersection of

the TSU boresight device target is coincident with the

intersection of the crosshairs within the small circle of the

borescope reticle.

NOTE

Unload the turret weapon subsystem and all

wing stores weaponry to prevent injury to per-

If there is insufficient height adjustment in the

sonnel through accidental firing of a weapon.

targets, the helicopter or the target assemblies

may need to be shimmed in order to align the

h Verity that all the components of the HSS, except

target assemblies properly.

the helmet sight assemblies, and the associated components

and panels are installed and are functionally operational.

i. Insert the borescope in the right tapered hole of the

Connect the shorting plug to the connector for the helmet

TSU boresight device. The borescope should be either,

sight assembly in the gunner's compartment (17P1

vertical or horizontal for best sighting results.

P247, AH-IS (MOD)).

4-4