TM 55-1520-240-T
7-1.4 FLIGHT CONTROL HYDRAULIC SYSTEM OPERATIONAL CHECK (Continued)
7-1.4
TASK
RESULT
20. Set FLT CONTR switch (14) to BOTH.
NO. 1 HYD FLT CONTR (Without 74 ) capsule (12) shall
go out. HYD 1 (With 74 ) capsule (12) shall go out.
21. Set POWER XFR NO. 1 switch (1) to OFF.
NO. 1 HYD FLT CONTR (Without 74 ) capsule (12) shall
come on. HYD 1 (With 74 ) capsule (12) shall come on.
22. Set FLT CONTR switch (14) to NO. 1 ON.
NO. 2 HYD FLT CONTR (Without 74 ) capsule (13) shall
stay out. If it comes on, go to Task 7-1.22. HYD 2 (With
74 ) capsule (13) shall stay out. If it comes on, go to Task
7-1.22.
23. Set FLT CONTR switch (14) to BOTH. Set POWER XFR
NO. 1 HYD FLT CONTR (Without 74 ) capsule (12) shall
NO. 1 switch to ON.
go out. HYD 1 (With 74 ) capsule (12) shall go out.
24. Set POWER XFR NO. 2 switch (2) to OFF.
NO. 2 HYD FLT CONTR (Without 74 ) capsule (13) shall
come on. HYD 2 (With 74 ) capsule (13) shall come on.
25. Set FLT CONTR switch (14) to NO. 2 ON.
NO. 1 HYD FLT CONTR (Without 74 ) capsule (12) shall
stay out. if it comes on, go to Task 7-1.23. HYD 1 (With
74 ) capsule (12) shall stay out. If it comes on, go to Task
7-1.23.
26. Set FLT CONTR switch (14) to BOTH. Set POWER
NO. 2 HYD FLT CONTR (Without 74) capsule (13) shall
XFR NO. 2 switch to ON.
go out. HYD 2 (With 74) capsule (13) shall go out.
27. Have pilot start engines and establish 100 percent rotor
NO. 1 and NO. 2 HYD FLT CONTR (Without 74)
rpm. Set POWER XFR NO. 1 and NO. 2 switches (1 and
capsules (12 and 13) shall be out. HYD 1 and HYD 2
2) to OFF.
(With 74) capsules (12 and 13) shall be out. If FLT
CONT NO. 1 HYDRAULIC PRESS indicator does not
read between 2500 and 3000 psi. and pointer fluctuates
more than 50 psi. or capsule (12) is on, replace No. 1
flight control hydraulic system pump. If FLT CONT NO. 2
HYDRAULIC PRESS indicator does not read between
2500 and 3000 psi. or pointer fluctuates more than 50 psi
and caps ule (13) is on, replace No. 2 flight control
hydraulic system pump.
TASK
RESULT
28. Check NO. 1 and NO. 2 PUMP FAULT lights (34 and If either light (34 or 35) is on, go to Task 7-1.24.
35).
FOLLOW-ON MAINTENANCE:
Have pilot shut down engines.
TM 55-1520-240-23:
Remove electrical power.
Disconnect battery.
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7-18 Change 17
