DOC AIRBUS | AMM A320FTest No.8 : Vibration Survey [IAE]
TASK 71-00-00-700-022-B
Test No.8 : Vibration Survey
1. Reason for the Job
You can use this test to make an analysis of the vibration characteristics of an engine.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Job Set-up
Subtask 71-00-00-710-202-A ** ON A/C NOT FOR ALL
Subtask 71-00-00-710-158-B ** ON A/C NOT FOR ALL
Subtask 71-00-00-862-075-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 12:55:59 UTC
Test No.8 : Vibration Survey
1. Reason for the Job
You can use this test to make an analysis of the vibration characteristics of an engine.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| 98F10103500000 | 2 | CHOCK-MLG,ENGINE RUN-UP |
| 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 71-00-00-700-012-B | Test No.9 : Low Pressure (LP) Compressor (Fan) Trim Balancing - One Shot Method |
| TASK 71-00-00-700-012-B-01 | Test No.9A : LP Compressor (Fan) Trim Balancing - Trial Weight Method |
| 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 71-00-00-710-047-A | Normal Engine Manual-Start Procedure |
| TASK 71-00-00-860-010-B | Engine Operation Limits, Guidelines and Special Procedures |
| TASK 71-00-00-860-011-C | Table of Idle Indications |
| TASK 71-00-00-860-011-C-01 | Table of Idle Indications |
| TASK 71-00-00-860-012-A | Engine Safety Precautions |
| TASK 77-32-34-869-010-A | Acquisition of the Unbalance Data on the Ground |
Tool InstallationSubtask 71-00-00-710-202-A ** ON A/C NOT FOR ALL
A. Make sure the dry out procedure for the High Pressure Turbine is necessary.
(1) Do the dry out procedure, if necessary, for the HPT (Ref. AMM TASK 71-00-00-700-013).
Subtask 71-00-00-861-077-A ** ON A/C NOT FOR ALL Subtask 71-00-00-710-157-A ** ON A/C NOT FOR ALL (1) Do the dry out procedure, if necessary, for the HPT (Ref. AMM TASK 71-00-00-700-013).
C. Do this test:
(3) If the aircraft begins to move while performing an engine run, immediately set all the thrust levers to the idle position.
(5) Make sure that the indications of operation are in the limits of operation (Ref. AMM TASK 71-00-00-860-011) if required.
4. ProcedureCAUTION:
DURING GROUND RUNNING, CONCERN FOR FAN BLADE INTEGRITY PROHIBITS STABILISED ENGINE OPERATION IN THE FOLLOWING SPEED RANGE:
(1) Make sure that the 98F10103500000 CHOCK-MLG,ENGINE RUN-UP are in position in front of each forward outboard MLG wheel. - 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.
NOTE: For general information, refer to the engine safety precautions (Ref. AMM TASK 71-00-00-860-012) and engine operation limits, guidelines and special procedures (Ref. AMM TASK 71-00-00-860-010).
(2) There must be two qualified persons in the cockpit when performing an engine run. One must monitor the outside and the aircraft behavior while the other performs the engine test. (3) If the aircraft begins to move while performing an engine run, immediately set all the thrust levers to the idle position.
NOTE: It is necessary in this test that engine 1 and engine 2 be run at the same time to give a thrust balance on the aircraft.
NOTE: On the lower ECAM DU:
(4) Start both of the engines by the normal engine automatic start procedure (Ref. AMM TASK 71-00-00-710-043) or the normal engine manual start procedure (Ref. AMM TASK 71-00-00-710-047). - For the N1 module, 1 unit = 0.3 IPS
- For the N2 module, 1 unit = 0.3 IPS.
(5) Make sure that the indications of operation are in the limits of operation (Ref. AMM TASK 71-00-00-860-011) if required.
Subtask 71-00-00-710-158-B ** ON A/C NOT FOR ALL
A. Do this test:
(1) Operate the engines at MIN IDLE for five minutes.
(2) Slowly increase the power of the engine which is not being tested to 1.08 EPR.
(3) Slowly increase the power of the test engine to 1.25 EPR for three minutes to let it become thermally stable.
(5) Prepare to make a record of data from the vibration sensor.
(a) Increase the power of the engine which is not being tested to 1.08 EPR minimum.
(b) Slowly increase the power of the test engine to 85 percent N1.
1 Make the acceleration rate so that the engine goes to 85 percent N1 power in not less that 120 seconds.
2 Make a record of all the vibration peaks and a record of the N1/N2 speeds and EPR at which the peaks occurred.
a Push the line key adjacent to the SAVE indication to record set of the vibration data displayed on the MCDU for the selected N1 speed(s) (Ref. AMM TASK 77-32-34-869-010).
(c) Slowly decrease the engine speed to MIN IDLE.
1 Make the deceleration rate so that the engine goes to MIN IDLE in not less than 120 seconds.
2 Make a record of all the vibration peaks (Ref. AMM TASK 77-32-34-869-010).
(d) Decrease the power of the engine which is not being tested to MIN IDLE.
(e) If you made a record of the vibration peaks during acceleration and deceleration, do the steps which follow :
3 Make a record of the average vibration reading.
4 The average vibration for which you made a record during the 30 seconds, must not exceed the limits listed in TASK (Ref. AMM TASK 71-00-00-860-010). See Section "Vibration Limits and Fan Trim Balance Vibration Guidelines"
(f) Vibration limits
(7) Do a shutdown by the discontinued start, restart and shutdown procedure (Ref. AMM TASK 71-00-00-710-018).
5. Close-up(1) Operate the engines at MIN IDLE for five minutes.
(2) Slowly increase the power of the engine which is not being tested to 1.08 EPR.
(3) Slowly increase the power of the test engine to 1.25 EPR for three minutes to let it become thermally stable.
NOTE: The vibration survey must be done only on an engine which has become thermally stable.
(4) Go back to MIN IDLE on both engines for six minutes. (5) Prepare to make a record of data from the vibration sensor.
NOTE: During the slow acceleration and deceleration which follows, engine vibration could go to one or more out-of-limits peaks (at specific N1 or N2 speeds). Be prepared to make a record of the N1, N2 percent and EPR at which these peaks occurs.
(6) Do an acceleration and deceleration as follows: (a) Increase the power of the engine which is not being tested to 1.08 EPR minimum.
(b) Slowly increase the power of the test engine to 85 percent N1.
1 Make the acceleration rate so that the engine goes to 85 percent N1 power in not less that 120 seconds.
2 Make a record of all the vibration peaks and a record of the N1/N2 speeds and EPR at which the peaks occurred.
a Push the line key adjacent to the SAVE indication to record set of the vibration data displayed on the MCDU for the selected N1 speed(s) (Ref. AMM TASK 77-32-34-869-010).
NOTE: Up to five set of data can be stored in the EVMU.
3 Let the engine become stable at 85 percent N1 for one minute before you continue. (c) Slowly decrease the engine speed to MIN IDLE.
1 Make the deceleration rate so that the engine goes to MIN IDLE in not less than 120 seconds.
2 Make a record of all the vibration peaks (Ref. AMM TASK 77-32-34-869-010).
(d) Decrease the power of the engine which is not being tested to MIN IDLE.
(e) If you made a record of the vibration peaks during acceleration and deceleration, do the steps which follow :
NOTE: If the test engine is to be run at 1.25 EPR or above, the engine which is not being tested must be run at 1.08 EPR.
1 Set the speed on the test engine where the peaks occured. NOTE: The engine must not be stabilised in the 61 percent to 74 percent N1 speed range. If the vibration peak occurs in this range select the highest vibration peak in the 75 percent to 85 percent N1 speed range instead. If no obvious vibration peak exists between 75 percent to 85 percent N1 and it is considered that the engine may exceed the vibration limits defined (Ref. AMM TASK 71-00-00-860-010) then you must perfom a trim balance (Ref. AMM TASK 71-00-00-700-012).
2 Let the engine become stable for 30 seconds. 3 Make a record of the average vibration reading.
4 The average vibration for which you made a record during the 30 seconds, must not exceed the limits listed in TASK (Ref. AMM TASK 71-00-00-860-010). See Section "Vibration Limits and Fan Trim Balance Vibration Guidelines"
(f) Vibration limits
| ------------------------------------------------------------------------------- |
| ! Location ! Overall ! N1 (Peak) ! N2 (Peak) ! |
| !------------------!-----------------!-------------------!--------------------! |
| ! Fan case ! 4.67 units ! 3.33 units ! 3.33 units ! |
| ! ! (1.4 IPS) ! (1.0 IPS) ! (1.0 IPS) ! |
| ------------------------------------------------------------------------------- |
NOTE: Vibration limits as stated are established from the test cell data.
NOTE: Engines that have vibration within the vibration limits are acceptable. Engines can be trim balanced if the overall vibration or N1 peak vibration is less than 2.0 IPS. After trim balance, vibration must at or below the overall or N1 peak limits. Engines that exceed the N2 peak limit cannot be trim balanced and must be disassembled.
(g) Go back to MIN IDLE both engines for five minutes. (7) Do a shutdown by the discontinued start, restart and shutdown procedure (Ref. AMM TASK 71-00-00-710-018).
Subtask 71-00-00-862-075-A ** ON A/C NOT FOR ALL