Periodic Preventive Maintenance Checks and Services Chart

TM 11-5821-277-20

and services given in the chart in the sequence

flying hours, concurrently with the aircraft peri-

odic preventive maintenance service schedule of

listed. Record all deficiencies in accordance with

the aircraft in which the radio set is installed to

the requirement of TM 38-750,

reduce out-of-service time. Perform all the checks

4-9. Periodic Preventive Maintenance Checks and Services Chart

References

Item to be inspected

Fig. 1-1.

Completeness ----------------- Be sure that radio set,is complete.

DA Para 310-4.

publications ----------------- Check to see that all pertinent publi-

cations are available. Technical

manuals must be complete and in

useable condition with all applicable

changes posted.

DA Para 310-7.

Modification work orders ------ Check to see that all URGENT MWO's

have been applied to equipment and

all NORMAL MWO's have been

scheduled.

a. Para 4-16.

Control unit ------------------ a. Remove control unit from instru-

ment and check for dirt and cor-

rosion.

b. Para 4-10.

b. Clean control unit.

c. None.

c. Inspect electrical connector at rear

of control unit for signs of obvious

physical damage.

d. Para 4-16.

d. Reinstall control unit.

Para 4-17.

Transceiver ------ - - - - - - - - - - a Remove transceiver from mounting

l nd inspect for dirt and corrosion.

b. Para 4-10.

b. Clean transceiver.

c. None.

c. Carefully inspect dual electrical con-

nector at rear of transceiver (fig.

1-7) for signs of physical damage

or evidence of improper mating.

a. Para 4-11.

Mounting - - - - - - - - - - - - - - - - - - - - - a. While transceiver is removed, check

mounting for dirt and corrosion

accumulation.

b. Para 4-10.

b. Clean mounting.

c. None.

c. Carefully inspect dual feedthrough

electrical connector at rear of

mounting for evidence of physical

damage or improper mating. Also

check to be sure that aircraft wir-

ing is securely soldered, or other-

wise connected, to pins at rear of

receptacle.

d. None.

d. Be sure that grounding strap is se-

curely fastened to frame of air-

craft.

e. None.

e. Be sure that mounting is securely

fastened to frame of aircraft.

f. None

f. Check to see that resilient (shock)

mounts operate smoothly and sup-

ply prescribed distance of travel.

Sequentially press l nd lift up each

end of mounting. Shockmount

should permit mounting to travel

both down and up one-sixth of an

inch from normal loaded position.

Pm-a 4-17.

Transceiver ------------------ Replace transceiver in mounting.

a. Para 4-7.

Radio set --------------------- a. Perform power-on procedure.

b. Para 4-7.

b. Accomplish test procedures.

4-6