Figure 4-7. Examples of pitch and roll adjustment procedures

TM 9-1270-212-14&P

in. Return the ACQ TRK STOW switch to STOW.

NOTE

Step n below is not necessary for HSS XM136

For HSS XM128 in an AH-1S(Mod) helicopter,

move the LOD 4 inches aft of the original position in

d and tighten the T-locks.

o. Slightly loosen the azimuth locking knob and the

elevation locking knob.

NOTE

Do not lean or stand on the helicopter during

the operations below.

p. Rotate the LOD to approximately 90 degrees right

and insert the borescope.

q. View through the borescope and adjust the LOD in

azimuth and elevation until the intersection of the

crosshairs of the borescope reticle coincides with the

intersection of the crosshairs of the gunner's HSS target on

the right target.

r. Tighten the azimuth locking knob and the elevation

angle locking knob.

s. Being careful not to pull or push against the

borescope, in the LOD, recheck the alignment of step q.

Remove the borescope.

t. Hold the ACQ TRK STOW switch to ACQ.

u. The technician viewing through the TSU shall record

the elevation discrepancy between the TSU horizontal

Figure 4-7. Examples of pitch and roll

crosshair and the TSU optics target horizontal crosshair.

adjustment procedures

Return the ACQ TRK STOW switch to STOW.

v. Slightly loosen the azimuth locking knob and

z. If the total difference between the two TSU

elevation angle locking knob.

discrepancies exceeds 4 mils, readjust the helmet sight rails

as given in aa and ab.

w. Rotate the LOD approximately 180 degrees left and

aa. To eliminate the roll error (fig. 4-7), loosen the rol

insert the borescope.

adjustment locking screws (fig. 4-5) and readjust the rails

by turning both the fore and aft roll adjustment screws in

x. Repeat steps q through u for the gunner's HSS target

equal amounts in the proper direction, as-stated below:

on the left target.

(1) To raise the TSU LOS, sight through the

y. Review the two TSU elevation discrepancies to

orescope and, using the roll adjustment screws, lower t h e

determine if roll misalignment exists (see fig. 4-7, step A).

4-10