TM 55-1520-240-T
15-1.4 APU VISUAL CHECK (CONTINUED)
15-1.4
TASK
RESULT
1.
Check APU fuel valve (1).
If fuel valve (1) is loose or damaged, tighten or
replace it as required. If electrical connector or
wiring to valve is damaged, replace connector or
repair or replace wiring as required.
2.
Check APU fuel boost pump (2).
If fuel boost pump (2) is loose or damaged, tighten
or replace it as required. If electrical connector or
wiring to pump is damaged, replace connector or
repair or replace wiring as required.
3.
Check APU combustor drain line (3).
If drain line (3) is kinked or damaged, replace it. If
it is loose, tighten it.
4.
Check APU spark plug (4), exciter cable
If spark plug (4), exciter cable (5), or ignition
(5), and ignition exciter (6).
exciter (6) is loose or damaged, tighten or replace
it as required.
5.
Check APU thermocouple cable (7).
If cable (7) is loose or damaged, tighten or replace
it as required.
6.
Check two APU fuel lines (8).
If any fuel line (8) is damaged, replace it.
7.
Check APU air inlet screen (9).
If screen (9) is clogged, clean it.
8.
Check APU oil level sight gage (10).
If oil level is low, service APU.
9.
Check APU combustor case (11) and
If either case (11 or 12) is cracked or damaged,
turbine case (12).
replace APU.
10. Check APU fuel line (13).
If fuel line (13) is kinked or damaged, replace it.
11. Check APU fuel shutoff manual valve (14).
If valve (14) is loose or damaged, tighten or
place it as required. If valve handle (15) is not in
ne with fuel line, set it in that position.
12. Check electronic sequence unit (ESU) (16).
If ESU (16) is loose or damaged, tighten or replace
as required. If electrical connector or wiring to
U is damaged, replace connector or repair or
place wiring as required. If bite information
art (17) is damaged, replace it.
13. Check APU switch (18).
If switch (18) is loose or damaged, tighten or
place it as required.
14. On helicopter with 33 , check cable
If cable adapter (19) is loose or damaged, tighten
adapter (19).
or replace it as required.
FOLLOW-ON MAINTENANCE:
TM 55-1520-240-23:
Left aft intertank bay access door closed
APU drip pan installed.
END OF TASK
Change 8 15-15
