TB 1-1520-238-20-110
c. Inspect APU fuel hose assembly. Refer to TM 1--1520--238--23P, figure 687, item 24 for the
AH--64A, or the IETM for the AH--64D.
(1) If the hose assembly is stamped with part number 7--211643064--3, the inspection is complete
and the red horizontal dash //--// entry may be cleared.
(2) If the hose assembly is stamped with part number 7--211643064, or the part number cannot
be determined, perform fuel leak inspection IAW para 8d.
d.
Fuel leak inspection.
(1) Disconnect APU controller/ecu connectors (2 each) per TM 1--1520--238--23 paragraph
15.23.3.c and 15.23.3.d for the AH--64A or the IETM [APU system, APU installation, control unit, electronic
(ECU) and the DAP 101C--1901--Series Interactive Electronic Technical Publication], steps 1 and 2 for the
AH--64D.
(2) Station an observer at the APU enclosure. Simultaneously with the inspection procedures in
(a) Visually inspect the hose and deck using an explosion proof flashlight.
(b) Observe for any increase in fuel odor once the hose is pressurized.
CAUTION
Broken stainless steel braiding may cause injury.
(c) Feel hose and surrounding area for fuel dampness.
(3) Inspection procedures for the AH--64A --
(a) Enter pilots crew station and locate the battery/external power switch. Place switch in
the "battery" position.
(b) Locate APU start/run switch. Place switch in the "run" position. Hold run position for
approximately 30 seconds to pressurize APU fuel system. Return APU start/run switch to the "off ' posi-
tion.
(c) Return battery switch to the "off" position.
(4) Inspection procedures for the AH--64D --
(a) Enter pilot's crew station and locate the battery/external power switch. Place switch in
the "battery" position.
(b) Locate APU start/stop switch. Lift cover and depress switch.
(c) Allow APU boost pump to operate for approximately 30 seconds. Depress APU start/stop
switch to turn off APU boost pump.
(d) Return battery switch to the "off" position.
(5) If fuel leakage/vapor or increase in odor is detected, proceed to paragraph 9a.
(6) If no leakage/vapor or increase in odor is detected --
(a) Reconnect APU controller/ECU per TM 1--1520--238--23 paragraph 15.23.6 or the IETM
[APU System, APU Installation, Control Unit, Electronic (ECU) and the DAP 101C--1901--Series Interac-
tive Electronic Technical Publication], steps 5 and 6.
(b) Reinstall APU cover.
(c) Proceed to para 9b.
e.
Conduct a recurring inspection of the APU fuel hose assembly P/N 7--211643064, as follows --
(1) The inspection procedures IAW paragraph 8d of this message will be completed every 10
flight hours/14 days.
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