Fan Trim Balance with the EVMU (One Shot Method) [IAE]

TASK 77-32-34-750-010-A
Fan Trim Balance with the EVMU (One Shot Method)

1. Reason for the Job
You can use this procedure for consecutive fan trim balances if necessary. If consecutive fan trim balances with this method do not give significant results, do a fan trim balance with the trial weight method.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 200 and 180 lbf.in (2.26 and 2.03 m.daN )

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 31-32-00-860-012-A	Procedure to Get Access to the SYSTEM REPORT/TEST/ENG Page
TASK 72-38-11-000-010-A	Removal of the Inlet Cone
TASK 72-38-11-400-010-A	Installation of the Inlet Cone
TASK 77-32-34-869-010-A	Acquisition of the Unbalance Data on the Ground
TASK 77-32-34-869-048-B	Unbalance Data : Read Ground Data, Read and Load Flight Data
Fan Trim Balance - One Shot Method

3. Job Set-up
Subtask 77-32-34-861-071-A ** ON A/C NOT FOR ALL

A. Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 77-32-34-865-080-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	ENGINE/ENG1 AND 2/EVMU	1EV	R44

Subtask 77-32-34-941-054-A ** ON A/C NOT FOR ALL

C. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 77-32-34-010-056-A ** ON A/C NOT FOR ALL

D. Remove the inlet cone fairing and the inlet cone from the front blade retaining ring (Ref. AMM TASK 72-38-11-000-010).

Subtask 77-32-34-860-067-A ** ON A/C NOT FOR ALL

E. Aircraft System Configuration
(1) Record the weight installed and their position on the front blade retaining ring (36 bolt flange) and on the inlet cone flange (24 bolt flange).

Subtask 77-32-34-869-102-A ** ON A/C NOT FOR ALL

F. Aircraft Maintenance Configuration
(1) To do this procedure flight or ground vibration data must be available (Ref. AMM TASK 77-32-34-869-048). (Ref. AMM TASK 77-32-34-869-010)
(2) On the MCDU 1(2), get the SYSTEM REPORT/TEST ENG page (Ref. AMM TASK 31-32-00-860-012).
(3) Push the key adjacent to the EVMU indication: the first EVMU page comes into view.
(4) Push the NEXT PAGE key.
(5) Push the key adjacent to the ENGINE UNBALANCE indication
(6) The EVMU ENGINE UNBALANCE menu comes into view.

4. Procedure
Subtask 77-32-34-750-052-A ** ON A/C NOT FOR ALL

A. Do the fan trim balance.

ACTION	RESULT
1.Push the line key adjacent to the ENG1(2) TRIM indication.	The EVMU ENG1(2) TRIM BALANCE METHOD SELECTION menu comes into view.
2.Push the line key adjacent to the ONE SHOT TRIM BALANCE indication.	The EVMU ENG1(2) CURRENT VIB DATA menu comes into view.
3.Regarding to the data that you use to do the trim balance, push the line key adjacent to the FLIGHT DATA or GROUND DATA or MANUAL INPUT indication. NOTE: The GROUND DATA are kept in the volatile memory of the EVMU. If there is de-energization of the aircraft electrical network after you acquire engine unbalance ground data, it will not be possible to use this data to calculate Trim Balance.	The applicable vibration data comes into view.
NOTE: If MANUAL INPUT indication is selected you must type RPM/MILS/DEG data on the MCDU keyboard. 4.Collect the vibration data on the result sheet or by a print of the MCDU screens. These data are necessary if you must do a trim balance with the trial weight method.
5.Push the line key adjacent to the CONT indication.	The EVMU ENG1 (2) ONE SHOT TRIM BAL INFLUENCE COEFF SELECT menu comes into view.
6.Regarding to the engine type on which you do the trim balance, push the line key adjacent to the engine type indication. NOTE: You can use specific coefficient to trim balance the engine. In this case you must type SPEED/KAMPL/KPHASE in the ENG1(2) SPECIFIC COEFF menu.	The EVMU ENG1(2) INST CURRENT WGHTS menu comes into view.
7.Push the line key adjacent to the 36 BOLT FLANGE indication.	The EVMU ENG1(2) CURRENT INST WGHT 36 BOLT FLANGE menu comes into view. Compare the data shown on the MCDU with the data collected in step E. for all of the 36 bolts and if necessary type on the keyboard the current weight installed. NOTE: If no balance weight is installed the N-A indication appears instead of the weight identification.
8.Push the line key adjacent to the CONT indication. NOTE: If the RETURN key is pressed the modifications on the bolt configuration will not be recorded.	The EVMU ENG1(2) INST CURRENT WGHTS menu comes into view.
9.Push the line key adjacent to the 24 BOLT FLANGE indication.	The EVMU ENG1(2) CURRENT INST WGHTS 24 BOLT FLANGE menu comes into view. Compare the data shown on the MCDU with the data collected in step E. for all of the 24 bolts and if necessary type on the keyboard the current weight installed. NOTE: If no balance weight is installed the N-A indication appears instead of the weight identification.
10.Push the line key adjacent to the CONT indication.	The EVMU ENG1(2) INST CURRENT WGHTS menu comes into view.
11.Push the line key adjacent to the BALANCE SOLUTION CONT indication.	The EVMU ENG1(2) WEIGHTS TO CHANGE menu comes into view. Do a print of this page and if there is more than one page, on the MCDU keyboard, push the NEXT PAGE pushbutton and do a print of each page. If you want to keep this new configuration push the line key adjacent to the CONFIG UPDATE indication. NOTE: If the line key adjacent to the CONFIG UPDATE indication is pushed, the new values replace the values in the ENG1(2) CURRENT INST WGHT menu.
12.On the MCDU, push the line select key adjacent to the RETURN indication until the CFDS menu page comes into view.

(1) On the 36 and 24 flanges change the balance weights as necessary.
(a) Install or remove the balance weights on the bolts as indicated on the MCDU page.
(b) TORQUE the bolts to between 200 and 180 lbf.in (2.26 and 2.03 m.daN )

5. Close-up
Subtask 77-32-34-410-053-A ** ON A/C NOT FOR ALL

A. Install the inlet cone fairing and the inlet cone on the front blade retaining ring (Ref. AMM TASK 72-38-11-400-010).

Subtask 77-32-34-942-056-A ** ON A/C NOT FOR ALL

B. Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 03:18:36 UTC