Acquisition of the Unbalance Data on the Ground [IAE]

TASK 77-32-34-869-010-A
Acquisition of the Unbalance Data on the Ground

1. Reason for the Job

NOTE: It is not possible to acquire and store unbalance ground data for the two engines at the same time. To acquire data for the two engines you must:
- acquire the data for one engine, then
- calculate and record the balance solution for that engine, then
- acquire the ground data for the other engine.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

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 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 31-32-00-860-012-A	Procedure to Get Access to the SYSTEM REPORT/TEST/ENG Page
TASK 31-60-00-860-001-A	EIS Start Procedure
TASK 71-00-00-700-013-A	Procedure to Dry Out the High Pressure Turbine (HPT) after Oil Contamination
TASK 71-00-00-710-018-A	Discontinued Start, Restart and Shutdown Procedures
TASK 71-00-00-710-043-A	Normal Engine Automatic-Start Procedure
TASK 71-00-00-860-010-B	Engine Operation Limits, Guidelines and Special Procedures
EVMU Menu
EVMU Engine Unbalance
Read and Acquire Ground Data

3. Job Set-up
Subtask 77-32-34-710-059-A ** ON A/C NOT FOR ALL

A. A. Dry Out the High Pressure Turbine.
(1) Do the dry out procedure for the High Pressure Turbine (Ref. AMM TASK 71-00-00-700-013).

Subtask 77-32-34-861-078-A ** ON A/C NOT FOR ALL

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

Subtask 77-32-34-865-086-A ** ON A/C NOT FOR ALL

C. 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 77-32-34-869-114-A ** ON A/C NOT FOR ALL

D. Do the EIS start procedure (upper ECAM display unit only) (Ref. AMM TASK 31-60-00-860-001).

Subtask 77-32-34-869-119-A ** ON A/C NOT FOR ALL

E. Do the steps D. to M. only if a Post Flight Report (PFR) is necessary at the end of the ground run. If a PFR is not necessary, go to step N.

NOTE: The Post Flight Report will not be automatically printed at the engines shut-down. At the end of the test, you can use the print function to get a PFR manual print out.

(1) Enter a new flight number through the MCDU.
(a) On the MCDU, push the INIT mode key.
(b) On the MCDU keyboard, enter a flight number (eight digits maximum).
(c) Push the line key adjacent to the FLT NBR indication.

Subtask 77-32-34-869-115-A ** ON A/C NOT FOR ALL

F. Start both engines and let them become stable at minimum idle for 5 minutes (Ref. AMM TASK 71-00-00-710-043).

Subtask 77-32-34-869-121-A ** ON A/C NOT FOR ALL

G. Hold the CFDS in Flight mode for more than 30 seconds before you open the following circuit breakers.

Subtask 77-32-34-865-088-A ** ON A/C NOT FOR ALL

H. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	FWS/FWC1/SPLY	3WW	F01

Subtask 77-32-34-869-120-A ** ON A/C NOT FOR ALL

I. After 5 seconds minimum, open the circuit breaker 2WW.

Subtask 77-32-34-865-089-A ** ON A/C NOT FOR ALL

J. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	CFDS/CFDIU/SPLY	2TW	J18
121VU	CFDS/CFDIU/BACK/UP	8TW	J17
121VU	EIS/FWC2/SPLY	2WW	Q07

Subtask 77-32-34-869-117-A ** ON A/C NOT FOR ALL

K. Start Chrono
(1) After 40 seconds close the circuit breakers 2TW and 8TW.
(2) After full CFDS initialization (GMT is shown on the lower ECAM DU), close circuit breaker 3WW for FWC1 or 2WW for FWC2.
(3) Wait for full FWC1(2) initialization (FWC1(2) FAULT message goes out of view).

Subtask 77-32-34-869-118-A ** ON A/C NOT FOR ALL

L. Get access to the ENGINE UNBALANCE menu
(1) On the 1(2) MCDU, get the SYSTEM REPORT/TEST ENG page (Ref. AMM TASK 31-32-00-860-012).
(2) Push the line key adjacent to the ENG VIBRATION indication: the first EVMU page comes into view.

EVMU Menu ** ON A/C NOT FOR ALL

(3) Push the NEXT PAGE function key: the second EVMU MENU page comes into view.

EVMU Menu ** ON A/C NOT FOR ALL

(4) Push the line key adjacent to the ENGINE UNBALANCE indication to get the ENGINE UNBALANCE program.
(a) The ENGINE UNBALANCE menu comes into view.

EVMU Engine Unbalance ** ON A/C NOT FOR ALL

Subtask 77-32-34-869-122-A ** ON A/C NOT FOR ALL

M. Do this step only if a PFR is not necessary at the end of the ground run.

NOTE: If a PFR is necessary, go to step 4.A.

(1) Start both engines and let them become stable at minimum idle for 5 minutes (Ref. AMM TASK 71-00-00-710-043).

4. Procedure
Subtask 77-32-34-869-116-B ** ON A/C NOT FOR ALL

CAUTION: OPERATE BOTH ENGINES FOR THIS TEST. POWER DIFFERENCE BETWEEN TWO ENGINES CAN MAKE THE AIRCRAFT UNSTABLE.

CAUTION: DO NOT INCREASE ENGINE SPEED TO MORE THAN 85 PERCENT (4803 RPM) N1. EXCESSIVE ENGINE SPEED CAN CAUSE AIRCRAFT BUFFET.

CAUTION: DURING GROUND RUNNING, CONCERN FOR FAN BLADE INTEGRITY PROHIBITS STABILISED ENGINE OPERATION IN THE FOLLOWING SPEED RANGE:

FOR PRE-SCN17/V A/C: DO NOT STABILISE THE ENGINE BETWEEN 61% TO 74% N1 SPEED RANGE
FOR POST-SCN17/V A/C: STABILISED OPERATION OF THE ENGINE BETWEEN APPROXIMATELY 60% TO 74% N1 SPEED RANGE (LIMITS ARE A FUNCTION OF OUTSIDE TEMPERATURE) WILL BE PROHIBITED BY THE EEC, AS THE SOFTWARE INCLUDES THE KEEP-OUT-ZONE FOR ON-GROUND, STATIC OPERATION.

A. Measure the Engine Vibration on Ground

NOTE: The engine can be trim balanced with the use of vibration data measured over a speed range of 75 to 85 percent (4237 to 4803 RPM). However, vibration data over the 81 to 85 percent (4576 to 4803 RPM) N1 range can give the best trim balance result.
It is recommended to measure engine vibration at 85, 83 and 81 percent (4803, 4689 and 4576 RPM) N1. If only one speed is allowed, use 85 percent (4803 RPM) N1.

NOTE: Make sure that the both engines are in the operating limits during the engine operation (Ref. AMM TASK 71-00-00-860-010).

(1) Increase the speed of the engine which is not being tested to 1.08 EPR.
(2) Slowly increase the test engine speed to the highest measuring point and keep the speed for one minute.

Subtask 77-32-34-860-072-B ** ON A/C NOT FOR ALL

B. Acquire the Ground Data:

ACTION	RESULT
1.Push the line key adjacent to the ENG1(2) GROUND ACQN indication.	The ENG1(2) GROUND ACQN page comes into view. Read and Acquire Ground Data ** ON A/C NOT FOR ALL The vibration data measured by the accelerometer A or B are displayed.
2.To get the phase and displacement with the accelerometer A: Push the line key adjacent to the ACC.A indication.	An asterisk comes into view adjacent to the ACC.A indication.
3.Push the line key adjacent to the SAVE indication to record the unbalance data for the selected N1 speed(s). NOTE: You can acquire the unbalance ground data for five different N1 speeds.
4.To read the unbalance ground data recorded with the accelerometer A: Push the line key adjacent to the READ indication to get the ENG1(2) READ GROUND ACQN page.	The table that shows the values comes into view.
5.To get the phase and displacement with the accelerometer B: Push the line key adjacent to the ACC.B indication.	An asterisk comes into view adjacent to the ACC.B indication.
6.Push the line key adjacent to the SAVE indication to record the unbalance data at the selected N1 speed(s). NOTE: You can acquire the unbalance ground data for five different N1 speeds.
To read the unbalance ground data recorded with the accelerometer B : Push the line key adjacent to the READ indication to get the ENG1(2) READ GROUND ACQN page.	The table that shows the values comes into view.
7.Slowly decrease the engine speed to the next lower measuring point. After the engine speed reaches the next measuring point, keep this speed for one minute before you measure the vibration.
Do the steps (B.2.) to (B.7.) for the other measuring points.
8.Push the line key adjacent to the RETURN indication.	The ENGINE UNBALANCE menu comes into view.

5. Close-up
Subtask 77-32-34-869-141-A ** ON A/C NOT FOR ALL

A. Close circuit breaker 2WW or 3WW and wait for CFDS come back in flight mode.

Subtask 77-32-34-860-073-A ** ON A/C NOT FOR ALL

B. Shutdown the engine (Ref. AMM TASK 71-00-00-710-018).

Subtask 77-32-34-862-070-A ** ON A/C NOT FOR ALL

C. De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 03:18:33 UTC