Installation of the Hydro Mechanical Unit (HMU) Drain Tube [CFMB]
TASK 71-73-49-400-027-A
Installation of the Hydro Mechanical Unit (HMU) Drain Tube
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 71-73-49-860-056-A ** ON A/C NOT FOR ALL
Subtask 71-73-49-420-058-B ** ON A/C NOT FOR ALL
Subtask 71-73-49-410-059-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 12:55:51 UTC
Installation of the Hydro Mechanical Unit (HMU) Drain Tube
1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [1000EM1] (ENGINE-1) | |
| 437AL, 438AR | |
| FOR [1000EM2] (ENGINE-2) | |
| 447AL, 448AR | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 71-13-00-010-040-B | Opening of the Fan Cowl Doors |
| TASK 71-13-00-410-040-B | Closing of the Fan Cowl Doors |
Subtask 71-73-49-860-056-A ** ON A/C NOT FOR ALL
A. Aircraft Maintenance Configuration
(1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
Subtask 71-73-49-010-074-A ** ON A/C NOT FOR ALL (1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
B. Make sure that the fan cowl doors are open: (Ref. AMM TASK 71-13-00-010-040)
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR
4. Procedure(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR
Subtask 71-73-49-420-058-B ** ON A/C NOT FOR ALL
A. Installation of the Hydro Mechanical Unit (HMU) Drain Tube
(1) Remove the protective covers from the Hydro Mechanical Unit and the drain tubes.
(2) Connect the HMU drain tube (5) to the HMU. Do not torque the coupling nut at this time.
(3) Connect the HMU drain tube (5) to the heat exchanger drain tube. Do not torque the coupling nut at this time.
(4) Attach the drain tube (5) to the CFMI support tube bracket with the bolt (25), the washers (30) and (35), the nut (40) and the clamp (45).
(5) Attach the drain tube (5) to the bracket with the clamp (10), the bolt (15) and the nut (20).
(6) Make sure that the HMU drain tube (5) is aligned correctly on the engine.
(7) TORQUE the nuts (20) and (40) to between 25 and 20 lbf.in (0.28 and 0.23 m.daN )
.
(8) Torque the drain tube coupling nuts.
.
5. Close-up(1) Remove the protective covers from the Hydro Mechanical Unit and the drain tubes.
(2) Connect the HMU drain tube (5) to the HMU. Do not torque the coupling nut at this time.
(3) Connect the HMU drain tube (5) to the heat exchanger drain tube. Do not torque the coupling nut at this time.
(4) Attach the drain tube (5) to the CFMI support tube bracket with the bolt (25), the washers (30) and (35), the nut (40) and the clamp (45).
(5) Attach the drain tube (5) to the bracket with the clamp (10), the bolt (15) and the nut (20).
(6) Make sure that the HMU drain tube (5) is aligned correctly on the engine.
(7) TORQUE the nuts (20) and (40) to between 25 and 20 lbf.in (0.28 and 0.23 m.daN )
. (8) Torque the drain tube coupling nuts.
CAUTION:
USE A SECOND WRENCH TO HOLD THE FITTINGS WHEN YOU LOOSEN/TIGHTEN THE TUBE COUPLING NUTS. THIS PREVENTS DAMAGE TO THE TUBES.
(a) TORQUE the drain tube (5) coupling nuts to between 160 and 150 lbf.in (1.81 and 1.70 m.daN )
. Subtask 71-73-49-410-059-A ** ON A/C NOT FOR ALL
Hydro Mechanical Unit (HMU) Drain Tube