Section VI. MAINTENANCE OF HELMET SIGHT ASSEMBLY

TM 9-1270-212-14&P

(2) Insure that the pilot and gunner helmet sight

b. Electrical Eyepiece Retraction Test. Perform the

assemblies are properly attached to their respective linkage

eyepiece retraction test as follows:

assemblies, and that the helmet sight cable connectors for

(1) Insure that the MASTER ARM switch on the

both pilot and gunner are connected.

pilot armament control panel is in the STBY position.

(3) For the gunner helmet sight assembly, place the

HSS RETICLE TEST (HSS RTCL TEST or HSS LAMP

(2) Set the MODE SELECT switch on the TOW

TEST) switch on the gunner armament control panel to

control panel (fig.2-9) to the STBY TOW, ARMED MAN,

TEST (or LAMP TEST) and insure that the reticle remains

or ARMED AUTO position.

lighted. If the reticle goes out, refer to paragraph 3-12 for

procecdures to replace the failed lamp assembly.

(3) Momentarily move the ACQ TRK STOW switch

(fig. 2-5) to ACQ and release it to TRK to insure that the

NOTE

eyepiece automatically retracts (rotates upward) out of the

field of view.

If the reticle light goes out while performing

step (3) check the position of the magnet in

(4) Leave the ACQ TRK STOW switch in the TRK

the receptacle before replacing lamp assembly.

position.

The white alignment dots may have to be

offset slightIy for reticle to light.

(5) Manually return the eyepiece to the operating

position.

(4) For the pilot helmet sight assembly, place the HS

RTCL TEST (or HSS RTCL TEST) switch on the pilot

(6) Press the PHS ACQ switch (fig. 2-5) and observe

armament control panel to the TEST position and insure

that the gunner's eyepiece automatically retracts.

that the reticle remains lighted. If the reticle goes out, refer

to paragraph 3-12 for procedures to replace the failed lamp

(7) Manually return the eyepiece to the operating

assembly.

position.

NOTE

If a failure occurs in any part of the eyepiece retraction

test, notify higher maintenance personnel.

If the reticle light goes out while performing

step (3), check the position of the magnet in

the receptacle before replacing lamp assembly.

The white alignment dots may have to be

offset slightly for reticle to light.

Section VI. MAINTENANCE OF HELMET SIGHT ASSEMBLY

3-11. General.

3-12. Replacement of Lamp Assembly (fig. B-3).

The maintenance performed on the helmet sight

a. Remove machine screw (9) holding lamp cover (10)

assembly at this level consists of

to the sight assembly.

a Cleaning the eyepiece

b. Carefully slide lamp cover (10) from sight housing

(36).

b. Cleaning the lens assembly

c. Hold component board assembly (35) in place with a

c. Replacing the lamp assembly.

small screwdriver and remove lamp assembly (11).

3-6