Section III. BORESIGHTING THE HELMET SIGHT ASSEMBLY

TM 9-1270-212-14&P

Section III. BORESIGHTING THE HELMET SIGHT ASSEMBLY

2-9. Helmet Boresighting.

2-7. General.

NOTE

This section contains a description of the HSS

organizational boresight kit and the procedures for

In the procedures below, where the nomencla-

boresighting the helmet sight assembly. These procedures

ture of a control, control position, or indicator

cover boresighting with helicopter power and boresighting

differs between the AH-1S(Mod) and the

with the helmet boresight cable.

AH-1S

helicopters, the basic nomen-

2-8. HSS Organizational Boresight Kit.

clature used is that for the AH-1S(Mod) heli-

copter and the nomenclature for the AH-1S

helicopters follows, in parentheses

The HSS organizational boresight kit (fig. 2-16) consists

and prefixed with an "or;" for example, "HSS

of a container, a helmet boresight tool, and a helmet

RETICLE TEST (HSS RTCL TEST or HSS

boresight cable. The complete kit weighs 10 pounds.

LAMP TEST)" in d below.

a. Container. The container is a lightweight, waterproof

a. Perform the procedures of paragraph 2-4, except for

case for transporting and storing the items.

the connection of hydraulic power. Insure that the

b. Helmet Boresight Tool. The helmet boresight tool

MASTER ARM switch on the pilot armament control panel

has two functions:

is set to STBY.

(1) To test the magnetically operated reed switch in

b. Connect the helmet cable connector (paragraph

the helmet receptacle.

2-6a(1)) and put on the helmet. Fasten the chin strap.

(2) To align the helmet receptacle with the reticle

c. Attach the helmet boresight tool to the helmet

line of sight.

magnetic receptacle.

The helmet boresight tool consists of a tube with an

d. Set the HSS RETICLE TEST (HSS RTCL TEST or

eyepiece at one end and an aperture and magnetic

HSS LAMP TEST) switch on the gunner armament control

connector at, the other. The connector mates with the

panel or the HS RTCL TEST (or HSS RTCL TEST) switch

on the pilot armament control panel to TEST and observe

helmet receptacle so that the line of sight of the tool is

that the reticle (fig. 2-17) is lighted. Adjust the appropriate

perpendicular to the mating surface of the receptacle

OFF BRT control for the desired reticle brightness.

magnet.

NOTE

If the boresight tool has been dropped or bent,

misalignment may result. Refer to TM

9-4931-363-14&P for inspection and test

procedure to verify accuracy of the boresight

In the step below, the second man must wear

tool.

safety glasses while looking through the helmet

boresight tool.

c. Helmet Boresight Cable. The helmet boresight cable

e. The operator, while seated in the gunner or pilot seat,

is 12 feet long and connects the helmet sight assembly

sights on a distant target (1000 meters or more) through

connector in the helicopter connector A1P1 on the helmet

the helmet sight eyepiece; a second man stands by the open

sight assembly. The cable allows the operators to boresight

door and sights through the helmet boresight tool at the

a helmet sight assembly outside the helicopter.

same target.

d. Socket-Head Screw Keys. T w o 1 / 1 6 - i n c h

f. If the view through the helmet boresight tool is

socket-head screw keys are provided to adjust the three

above, below, left, or right of the target (first column of

socket-head screws in the helmet sight receptacle during

table 2-10), loosen and then tighten the three adjustment

helmet boresighting.

2-18