DOC AIRBUS | AMM A320FTest No.9 : Low Pressure (LP) Compressor (Fan) Trim Balancing - One Shot Method [IAE]
TASK 71-00-00-700-012-B
Test No.9 : Low Pressure (LP) Compressor (Fan) Trim Balancing - One Shot Method
A. This TASK gives an instruction for Test No.9 LP Compressor (fan) trim balancing (one shot method).
B. Trim balance procedures for the LP Compressor (Fan) rotor have the folowing two methods:
(1) Test 9: This procedure uses vibration amplitude and unbalance phase angle indication which are identified by Engine Vibration Monotoring Unit (EVMU), then unbalance moment weight and actual phase angle are calculated. For the calculation it is necessary to use Influence Coefficients. It consists of the following:
(a) Mass Coefficient: Relation of vibration amplitude indication (mils) to unbalance moment weight (oz. in).
(b) Phase lag: Different angle between actual phase angle and EVMU phase angle indication.
(2) The detailed values at each speed are given in these procedures. Test 9 requires fewer engine runs than Test 9A.
(3) Test 9A: This procedure uses three trial trim balance weights (dummy weights). It makes you compare the actual unbalance vibration indication with the unbalance indication with the three trial balance weights installed at the consecutive positions (bolt holes). The data is vectorially plotted to find the phase angle and the vibration amount necessary for the final trim balance. Test 9A is able to get more accurate balancing than Test 9.
C. As an alternative solution, you can use the Fan Trim Balance with the EVMU (refer to 77-32-34 pb 501)
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Referenced Information
3. Job Set-up
Subtask 71-00-00-869-190-A ** ON A/C NOT FOR ALL
Subtask 71-00-00-710-137-A ** ON A/C NOT FOR ALL
(a) Examine the engine configuration. Make sure that:
1 The fan blades were not replaced since last flight.
2 The fan blades were not repaired since last flight.
3 Removal and installation of the LP compressor (fan) module were not done since last flight.
4 Engine repair in shop was not done since last flight.
(b) Read the record of engine vibration data which was measured with the EVMU in flight (Ref. AMM TASK 77-32-34-869-048).
1 Make sure that the record includes the N1 speeds, the vibration amplitudes and the phase angles measured over a speed range of 80 to 93 percent (4520 to 5255 RPM) N1.
2 Write the data on the Record Sheet 1.
(c) If all the conditions in steps (a) and (b) are satisfactory, the vibration data measured in flight can be used. Vibration measurement on ground is not necessary. Go to step D.
(d) If one or more conditions are not satisfactory, the vibration data measured in flight can not be used. Go to step C to measure the engine vibration on ground.
Subtask 71-00-00-710-216-A ** ON A/C NOT FOR ALL
(2) Increase the speed of the engine which is not being tested to 1.08 EPR.
(4) Measure N1 speed, vibration amplitude (U) and phase angle (A) with the EVMU (Ref. AMM TASK 77-32-34-869-048). Write them on the Record Sheet 1.
(5) Slowly decrease the engine speed to the next lower measuring point.
(6) After the engine speed reaches the next measuring point, keep this speed for one minute before you measure the vibration.
(7) Do step (4).
(8) Do steps (5), (6) and (7) for subsequent measuring points.
(9) Decrease the engine speed and shutdown the engines (Ref. AMM TASK 71-00-00-710-018).
Subtask 71-00-00-820-053-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 02:28:20 UTC
Test No.9 : Low Pressure (LP) Compressor (Fan) Trim Balancing - One Shot Method
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
1. Reason for the JobA. This TASK gives an instruction for Test No.9 LP Compressor (fan) trim balancing (one shot method).
B. Trim balance procedures for the LP Compressor (Fan) rotor have the folowing two methods:
(1) Test 9: This procedure uses vibration amplitude and unbalance phase angle indication which are identified by Engine Vibration Monotoring Unit (EVMU), then unbalance moment weight and actual phase angle are calculated. For the calculation it is necessary to use Influence Coefficients. It consists of the following:
(a) Mass Coefficient: Relation of vibration amplitude indication (mils) to unbalance moment weight (oz. in).
(b) Phase lag: Different angle between actual phase angle and EVMU phase angle indication.
(2) The detailed values at each speed are given in these procedures. Test 9 requires fewer engine runs than Test 9A.
(3) Test 9A: This procedure uses three trial trim balance weights (dummy weights). It makes you compare the actual unbalance vibration indication with the unbalance indication with the three trial balance weights installed at the consecutive positions (bolt holes). The data is vectorially plotted to find the phase angle and the vibration amount necessary for the final trim balance. Test 9A is able to get more accurate balancing than Test 9.
C. As an alternative solution, you can use the Fan Trim Balance with the EVMU (refer to 77-32-34 pb 501)
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 1M(3 FT) |
| No specific | AR | MAT - WORK |
| No specific | AR | WARNING NOTICE(S) |
| No specific | Torque wrench: range to between 220 and 180 lbf.in (2.49 and 2.03 m.daN )  | |
| 98F10103500000 | 2 | CHOCK-MLG,ENGINE RUN-UP |
| IAE1J12310 | 1 | PROGRAM-TRIM BALANCE |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.V06-069) | marker |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 70-23-11-911-013-A | General Torque Tightening Techniques |
| TASK 71-00-00-700-013-A | Procedure to Dry Out the High Pressure Turbine (HPT) after Oil Contamination |
| TASK 71-00-00-700-022-B | Test No.8 : Vibration Survey |
| 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 71-00-00-860-012-A | Engine Safety Precautions |
| 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 |
Subtask 71-00-00-869-190-A ** ON A/C NOT FOR ALL
A. Safety Precautions
(1) Make sure that the 98F10103500000 CHOCK-MLG,ENGINE RUN-UP are in position in front of each forward outboard MLG wheel.
(3) If the aircraft begins to move while performing an engine run, immediately set all the thrust levers to the idle position.
4. Procedure(1) Make sure that the 98F10103500000 CHOCK-MLG,ENGINE RUN-UP are in position in front of each forward outboard MLG wheel.
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.
Subtask 71-00-00-710-137-A ** ON A/C NOT FOR ALL
CAUTION:
DURING GROUND RUNNING, CONCERN FOR FAN BLADE INTEGRITY PROHIBITS STABILISED ENGINE OPERATION IN THE FOLLOWING SPEED RANGE:
A. Preparation for the Test - 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: If the vibration exceeds the limits, slowly decrease the engine speed to idle, shutdown the engine and find the cause.
NOTE: Angles are identified in a counterclockwise direction when you look rearward from the engine front.
NOTE: Speed (N1) is given as a percentage of LP shaft turn speed. 100 percent = 5650 RPM.
NOTE: Vibration amplitude (U) is the N1 order vibration amplitude on the Engine Vibration Monitoring Unit (EVMU) system. The unit for vibration amplitude (U) is shown in Mils (P-P).
NOTE: Phase angle (A) is the indicated angle in degrees of peak vibration amplitude from the EVMU system.
NOTE: Phase lag (B) is the different angle between the actual phase angle and the EVMU phase angle indication (A).
NOTE: Trim amount (TA) is moment weight value (oz.in) of rotor unbalance. It must be corrected by installation of the trim balance weights.
NOTE: Mass coefficient (K) is ratio of the trim amount (TA) to the vibration amplitude (U).
NOTE: Balance effect is change in the rotor unbalance moment weight value caused by a group of the trim balance weights.
NOTE: Balance effect error (TE) is the moment weight value of the remaining rotor unbalance after installation of the trim balance weights.
NOTE: Trim angular position is the actual unbalance (light) position on the rotor.
NOTE: Trim phase angle (TP) is the angle from the top position to the trim angular position on the rotor.
NOTE: Weight set is a group of trim balance weights that are installed at consecutive bolt holes.
NOTE: Weight par is a pair of the trim balance weights that are installed at two bolt holes.
(1) Examine the engine configuration and the vibration data record in flight to find if the vibration data can be used (a) Examine the engine configuration. Make sure that:
1 The fan blades were not replaced since last flight.
2 The fan blades were not repaired since last flight.
3 Removal and installation of the LP compressor (fan) module were not done since last flight.
4 Engine repair in shop was not done since last flight.
(b) Read the record of engine vibration data which was measured with the EVMU in flight (Ref. AMM TASK 77-32-34-869-048).
1 Make sure that the record includes the N1 speeds, the vibration amplitudes and the phase angles measured over a speed range of 80 to 93 percent (4520 to 5255 RPM) N1.
2 Write the data on the Record Sheet 1.
(c) If all the conditions in steps (a) and (b) are satisfactory, the vibration data measured in flight can be used. Vibration measurement on ground is not necessary. Go to step D.
(d) If one or more conditions are not satisfactory, the vibration data measured in flight can not be used. Go to step C to measure the engine vibration on ground.
B. 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 71-00-00-710-139-A ** ON A/C NOT FOR ALL (1) Do the dry out procedure for the High Pressure Turbine (Ref. AMM TASK 71-00-00-700-013).
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.
C. Measure the Engine Vibration on Ground (Ref. AMM TASK 77-32-34-869-010)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 measured in the N1 range 81 to 85 percent (4577 to 4803 RPM) can give the best trim balance result.
It is recommended to measure engine vibration at 85, 83 and 81 percent (4803, 4690 and 4577 RPM) N1. If only one speed is allowed, use 85 percent (4803 RPM) N1.
It is recommended to measure engine vibration at 85, 83 and 81 percent (4803, 4690 and 4577 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) and (Ref. AMM TASK 71-00-00-860-012).
(1) Start the both 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). (2) Increase the speed of the engine which is not being tested to 1.08 EPR.
CAUTION:
CONCERN FOR FAN BLADE INTEGRITY PROHIBITS STABILIZED ENGINE OPERATION BETWEEN 61% TO 74% N1 SPEED RANGE.
(3) Slowly increase power of the test engine speed to the highest measuring point and keep the speed for one minute. (4) Measure N1 speed, vibration amplitude (U) and phase angle (A) with the EVMU (Ref. AMM TASK 77-32-34-869-048). Write them on the Record Sheet 1.
(5) Slowly decrease the engine speed to the next lower measuring point.
(6) After the engine speed reaches the next measuring point, keep this speed for one minute before you measure the vibration.
(7) Do step (4).
(8) Do steps (5), (6) and (7) for subsequent measuring points.
(9) Decrease the engine speed and shutdown the engines (Ref. AMM TASK 71-00-00-710-018).
D. Calculate the Trim Amount (TA) and the Trim Phase Angle (TP) from the Engine Vibration Data (Method 1)
(1) Do this step for each N1 speed in the Record Sheet 1.
(a) Get the mass coefficient (K) and the phase lag (B) for the N1 speed from the Table 1 or Table 2.
Write them on the Record Sheet 1.
(b) Multiply the vibration amplitude (U) with the mass coefficient (k) to get the trim amount. Write it on the Record Sheet 1
(c) Add the phase lag (B) to the phase angle (A) to get the trim phase angle. Write it on the Record Sheet 1
(2) Calculate the average (TA) of the trim amount and the average (TP) of the trim phase angle. Write them on the Record Sheet 1
(3) Write a line which indicates trim angular position on the record sheet 2-2.
(a) Write a line at the angular position apart from the top position by the trim phase angle (TP).
(b) Write the letters "TP" near the line.
Subtask 71-00-00-820-065-A ** ON A/C NOT FOR ALL (1) Do this step for each N1 speed in the Record Sheet 1.
(a) Get the mass coefficient (K) and the phase lag (B) for the N1 speed from the Table 1 or Table 2.
Write them on the Record Sheet 1.
(b) Multiply the vibration amplitude (U) with the mass coefficient (k) to get the trim amount. Write it on the Record Sheet 1
(c) Add the phase lag (B) to the phase angle (A) to get the trim phase angle. Write it on the Record Sheet 1
(2) Calculate the average (TA) of the trim amount and the average (TP) of the trim phase angle. Write them on the Record Sheet 1
(3) Write a line which indicates trim angular position on the record sheet 2-2.
(a) Write a line at the angular position apart from the top position by the trim phase angle (TP).
(b) Write the letters "TP" near the line.
E. Calculate the Trim Amount and the Trim Phase Angle from the Engine Vibration Data with the Computer Program (Method 2)
(1) Install the one shot trim balance program, IAE1J12310 PROGRAM-TRIM BALANCE to the computer. Refer to the operation manual of the program for installation procedure.
(2) Calculate the trim amount and the trim phase angle with the program.
Subtask 71-00-00-941-070-A ** ON A/C NOT FOR ALL (1) Install the one shot trim balance program, IAE1J12310 PROGRAM-TRIM BALANCE to the computer. Refer to the operation manual of the program for installation procedure.
(2) Calculate the trim amount and the trim phase angle with the program.
F. 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 71-00-00-941-071-A ** ON A/C NOT FOR ALL (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).
G. Put the Ground Support Equipment in to Position
(1) Put the ACCESS PLATFORM 1M(3 FT) in to position to give access to the engine.
(2) Put the MAT - WORK in the air intake cowl.
Subtask 71-00-00-020-066-A ** ON A/C NOT FOR ALL (1) Put the ACCESS PLATFORM 1M(3 FT) in to position to give access to the engine.
(2) Put the MAT - WORK in the air intake cowl.
NOTE: Make sure that the red warning pennants of the workmat can be seen externally.
Make sure that the workmat has sufficient dimensions to give full protection to the lower, half of the air intake cowl.
Make sure that the workmat has sufficient dimensions to give full protection to the lower, half of the air intake cowl.
H. Remove the Inlet Cone Fairing (8) (Ref. AMM TASK 72-38-11-000-010)
(1) Make a temporary mark on the inlet cone (7) and the inlet cone fairing with marker (Material No.V06-069) to identify the initial position of the inlet cone fairing.
(a) As an alternative to the marker (Material No.V06-069) , it is permitted to use a marker that is specified in IAE V2500 Standard Practices Manual (SPP-V2500-1IA) 70-09-01-400-501 - Procedure To Make Temporary Marks On Components And Assemblies.
(2) Remove the six bolts (9) and the inlet cone fairing from the inlet cone.
(3) Find the existing trim balance weights (10), (11), (12), and/or (13) and the bolt holes "A" on the inlet cone flange.
Write their positions on the Record Sheet 2-2.
Subtask 71-00-00-869-241-A ** ON A/C NOT FOR ALL (1) Make a temporary mark on the inlet cone (7) and the inlet cone fairing with marker (Material No.V06-069) to identify the initial position of the inlet cone fairing.
(a) As an alternative to the marker (Material No.V06-069) , it is permitted to use a marker that is specified in IAE V2500 Standard Practices Manual (SPP-V2500-1IA) 70-09-01-400-501 - Procedure To Make Temporary Marks On Components And Assemblies.
(2) Remove the six bolts (9) and the inlet cone fairing from the inlet cone.
(3) Find the existing trim balance weights (10), (11), (12), and/or (13) and the bolt holes "A" on the inlet cone flange.
Write their positions on the Record Sheet 2-2.
NOTE: The bolt holes "A" are the holes which are used to install the inlet cone fairing bolts (9).
I. Make a Selection of the Flange on Which the Trim Balance Weights are to be Installed
(1) Get the trim amount (TA) and the trim phase angle (TP) from the Record Sheet 1.
(2) Get the position of the existing trim balance weights on the inlet cone flange from the Record Sheet 2-2
(3) Make sure that the following conditions are satisfactory:
(a) No existing trim balance weight is installed at the bolt hole on the inlet cone flange within 90 degrees of the trim angular position (TP).
(b) The trim amount (TA) is less than 12 oz.in.
(4) If both conditions in step (3) are satisfactory, use one of the inlet cone flange and the front blade retaining ring flange
(a) If you use the inlet cone flange, go to step K.
(b) If you use the front blade retaining ring flange, go to step P.
(5) If one or two conditions in step (3) are not satisfactory, use the front blade retaining ring flange. Go to step P.
Subtask 71-00-00-820-066-A ** ON A/C NOT FOR ALL (1) Get the trim amount (TA) and the trim phase angle (TP) from the Record Sheet 1.
(2) Get the position of the existing trim balance weights on the inlet cone flange from the Record Sheet 2-2
(3) Make sure that the following conditions are satisfactory:
(a) No existing trim balance weight is installed at the bolt hole on the inlet cone flange within 90 degrees of the trim angular position (TP).
(b) The trim amount (TA) is less than 12 oz.in.
(4) If both conditions in step (3) are satisfactory, use one of the inlet cone flange and the front blade retaining ring flange
(a) If you use the inlet cone flange, go to step K.
(b) If you use the front blade retaining ring flange, go to step P.
(5) If one or two conditions in step (3) are not satisfactory, use the front blade retaining ring flange. Go to step P.
J. Calculate the Part Numbers and the Positions of the Trim Balance Weights which are to be Installed on the Inlet Cone Flange (24 bolt flange) (Method 1)
(b) Get the weight set and/or the weight pairs, of which total balance effect value is within 0.5 oz.in. of the amount (TA), from Table 4 and Table 5.
(d) Calculate the sum (SA) of the balance effects. Write it on the Record Sheet 2-1.
(e) Subtract the value TA from the value SA. Write the result as the balance effect error (TE) on the Record Sheet 2-1.
(f) Make sure that the value TE is between -0.5 and 0.5 oz.in.
(2) Calculate the trim balance weight positions to let the balance effect position agree with the trim phase angle (TP).
(a) Get the trim phase angle (TP) from the Record Sheet 1.
Write the trim phase angle with line "TP" on the Record Sheet 2-2.
(b) Get the number of weights or the number of hole pitches of each weight set/pair from the Record Sheet 2-1.
(c) Write the center line of each weight set/pair on the Record Sheet 2-2.
The center line must be within 7.5 degrees of the trim angular position (TP).
(d) Calculate the trim balance weight positions with the center line and the number of weights or the number of hole pitches.
Write the positions on the Record Sheet 2-2.
(3) Make sure that the following conditions are satisfactory:
(a) Two or more trim balance weights are not installed at one bolt hole "B".
(b) The trim balance weights are not installed at the bolt holes "A".
(4) If all the conditions in step (3) are satisfactory, this SUBTASK is completed. Go to step L.
(5) If one or more conditions in step (3) are not satisfactory, go to step (1) and use other weight set and/or weight pairs.
Subtask 71-00-00-820-067-A ** ON A/C NOT FOR ALL NOTE: Purpose of this SUBTASK is to find the trim balance weights of which balance effect value and position agree with the trim amount (TA) and the trim phase angle (TP).
NOTE: The trim balance weights are given with a combination of one weight set and/or a few weight pairs.
A weight set/pair gives balance effect to the fan rotor at the center line position of weight set/pair. You must get the combination of weight set/pairs of which total balance effect value and position agree with the trim amount (TA) and the trim phase angle (TP).
(1) Calculate the combination of the weight set and/or the weight pairs of which total balance effect agrees with the trim amount (TA). A weight set/pair gives balance effect to the fan rotor at the center line position of weight set/pair. You must get the combination of weight set/pairs of which total balance effect value and position agree with the trim amount (TA) and the trim phase angle (TP).
NOTE: If you find two or more combinations of the weight set/pairs of which balance effect is within the limits, use one of them.
(a) Get the trim amount (TA) from the Record Sheet 1. (b) Get the weight set and/or the weight pairs, of which total balance effect value is within 0.5 oz.in. of the amount (TA), from Table 4 and Table 5.
NOTE: If you find two or more combinations of the weight set/pairs of which balance effects are within the limits, use one combination.
(c) Write each weight part No., balance effect, type of group and number of weights or number of hole pitches on the Record Sheet 2-1. (d) Calculate the sum (SA) of the balance effects. Write it on the Record Sheet 2-1.
(e) Subtract the value TA from the value SA. Write the result as the balance effect error (TE) on the Record Sheet 2-1.
(f) Make sure that the value TE is between -0.5 and 0.5 oz.in.
(2) Calculate the trim balance weight positions to let the balance effect position agree with the trim phase angle (TP).
(a) Get the trim phase angle (TP) from the Record Sheet 1.
Write the trim phase angle with line "TP" on the Record Sheet 2-2.
(b) Get the number of weights or the number of hole pitches of each weight set/pair from the Record Sheet 2-1.
(c) Write the center line of each weight set/pair on the Record Sheet 2-2.
The center line must be within 7.5 degrees of the trim angular position (TP).
(d) Calculate the trim balance weight positions with the center line and the number of weights or the number of hole pitches.
Write the positions on the Record Sheet 2-2.
(3) Make sure that the following conditions are satisfactory:
(a) Two or more trim balance weights are not installed at one bolt hole "B".
(b) The trim balance weights are not installed at the bolt holes "A".
(4) If all the conditions in step (3) are satisfactory, this SUBTASK is completed. Go to step L.
(5) If one or more conditions in step (3) are not satisfactory, go to step (1) and use other weight set and/or weight pairs.
K. Calculate the part numbers and the positions of the trim balance weights which are to be installed on the inlet cone flange (24 bolt flange) with the computer program (Method 2)
(1) Calculate with the one shot trim balance program, IAE1J12310 PROGRAM-TRIM BALANCE.
(2) Make sure that the remaining unbalance is not more than 0.5 oz.in.
(3) Write the calculated result on the Record Sheet 2-2.
Subtask 71-00-00-420-070-A ** ON A/C NOT FOR ALL (1) Calculate with the one shot trim balance program, IAE1J12310 PROGRAM-TRIM BALANCE.
(2) Make sure that the remaining unbalance is not more than 0.5 oz.in.
(3) Write the calculated result on the Record Sheet 2-2.
L. Install the Trim Balance Weights to the Inlet Cone Flange (24 bolt flange)
(2) Install the trim balance weight (10), (11), (12) or (13) at the bolt hole with the bolt (15).
(b) Identify the trim balance weight with the mark written on the weight.
(3) TORQUE the bolt (15) to between 220 and 180 lbf.in (2.49 and 2.03 m.daN ) (Ref. AMM TASK 70-23-11-911-013).
Subtask 71-00-00-420-079-A ** ON A/C NOT FOR ALL NOTE: Do steps (1) thru (3) for one bolt hole at a time. Do these steps until you install all the trim balance weights.
(1) Remove the bolt (15) and the washer (14) from one of the bolt holes where, the trim balance weights are to be installed, given in the Record Sheet 2-2. (2) Install the trim balance weight (10), (11), (12) or (13) at the bolt hole with the bolt (15).
NOTE: Do not install the washer (14) at the bolt where the trim balance weight is installed.
(a) Use the trim balance weight of which part number is given in the Record Sheet 2-2. (b) Identify the trim balance weight with the mark written on the weight.
(3) TORQUE the bolt (15) to between 220 and 180 lbf.in (2.49 and 2.03 m.daN )
(Ref. AMM TASK 70-23-11-911-013). M. Install the Inlet Cone Fairing (8).
(1) Install the inlet cone fairing to the initial position with the six bolts (9).
(2) TORQUE the bolts to between 220 and 180 lbf.in (2.49 and 2.03 m.daN ) (Ref. AMM TASK 70-23-11-911-013).
(3) Go to step T.
Subtask 71-00-00-020-067-A ** ON A/C NOT FOR ALL (1) Install the inlet cone fairing to the initial position with the six bolts (9).
(2) TORQUE the bolts to between 220 and 180 lbf.in (2.49 and 2.03 m.daN )
(Ref. AMM TASK 70-23-11-911-013). (3) Go to step T.
N. Remove the Inlet Cone (7) (Ref. AMM TASK 72-38-11-000-010).
(2) Remove the bolts (15), the washers (14), the inlet cone and the existing trim balance weights.
(3) Look for the front blade retaining ring flange (36 bolt flange) and find the positions of the existing trim weights (1), (2), (3) and/or (4). Write them on the Record Sheet 3-2.
Subtask 71-00-00-820-068-A ** ON A/C NOT FOR ALL NOTE: This SUBTASK is done to prepare trim balance weight installation to the front blade retaining ring.
(1) Make temporary marks on the inlet cone, the existing trim balance weights (10), (11), (12) and/or (13) and the front blade retaining ring with marker (Material No.V06-069) . NOTE: Temporary mark is necessary to identify their initial positions.
(a) As an alternative to the marker (Material No.V06-069) , it is permitted to use a marker that is specified in IAE V2500 Standard Practices Manual (SPP-V2500-1IA) 70-09-01-400-501 - Procedure To Make Temporary Marks On Components And Assemblies. (2) Remove the bolts (15), the washers (14), the inlet cone and the existing trim balance weights.
(3) Look for the front blade retaining ring flange (36 bolt flange) and find the positions of the existing trim weights (1), (2), (3) and/or (4). Write them on the Record Sheet 3-2.
O. Calculate the Part Numbers and the Positions of the Trim Balance Weights which are to be Installed on the Front Blade Retaining Ring Flange (36 bolt flange) (Method 1)
(a) Get the trim amount (TA) from the Record Sheet 1.
(b) Get the weight set and/or weight pairs, of which total balance effect value is within 0.5 oz.in. of the amount TA, from Table 6 and Table 7
Balance Effect of the Trim Balance Weights on the Front Blade Retaining Ring Flange ** ON A/C NOT FOR ALL
Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL
(d) Calculate the sum (SA) of the balance effects. Write it on the Record Sheet 3-1.
Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL
(e) Subtract the value TA from the value SA. Write the result as the balance effect error (TE) on the Record Sheet 3-1.
Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL
(f) Make sure that the value TE is between -0.5 and 0.5 oz.in.
(2) Calculate the trim balance weight positions to let the balance effect position agree with the trim phase angle (TP).
(a) Get the trim phase angle (TP) from the Record Sheet 1.
Write the trim phase angle with line "TP" on the Record Sheet 3-2.
(b) Get the number of weights or the number of hole pitches of each weight set/pair from the Record Sheet 3-1.
Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL
(c) Write the center line of each weight set/pair on the Record Sheet 3-2.
The center line must be within 7.5 degrees of the Trim Phase Angle (TP).
(d) Calculate the trim balance weight positions with the center line and the number of weights or the number of hole pitches.
Write the positions on the Record Sheet 3-2.
(3) Make sure that the following condition is satisfactory:
(a) Two or more trim balance weights are not installed at one bolt hole.
(4) If the condition in step (3) is satisfactory, this SUBTASK is completed. Go to step R.
(5) If the condition in step (3) is not satisfactory, go to step (1) and use other weight set and/or weight pairs.
Subtask 71-00-00-820-069-A ** ON A/C NOT FOR ALL NOTE: Purpose of this SUBTASK is to find the trim balance weights of which effect value and position agree with the trim amount (TA) and the trim phase angle (TP).
NOTE: The trim balance weights are given with a combination of one weight set and/or a few weight pairs.
A weight set/pair gives balance effect to the fan rotor at the position of weight set/pair center line. You must get the combination of weight set/pairs of which total balance effect value and position agree with the trim amount (TA) and the trim phase angle (TP).
(1) Calculate the weight set and/or the weight pairs of which total balance effect agrees with the trim amount (TA). A weight set/pair gives balance effect to the fan rotor at the position of weight set/pair center line. You must get the combination of weight set/pairs of which total balance effect value and position agree with the trim amount (TA) and the trim phase angle (TP).
(a) Get the trim amount (TA) from the Record Sheet 1.
(b) Get the weight set and/or weight pairs, of which total balance effect value is within 0.5 oz.in. of the amount TA, from Table 6 and Table 7
Balance Effect of the Trim Balance Weights on the Front Blade Retaining Ring Flange ** ON A/C NOT FOR ALL NOTE: If you find two or more combinations of the weight set/pairs of which balance effects are within the limits, use one combination.
(c) Write each weight part No., balance effect, type of group and number of weights or number of hole pitches on the Record Sheet 3-1 Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL (2) Calculate the trim balance weight positions to let the balance effect position agree with the trim phase angle (TP).
(a) Get the trim phase angle (TP) from the Record Sheet 1.
Write the trim phase angle with line "TP" on the Record Sheet 3-2.
(b) Get the number of weights or the number of hole pitches of each weight set/pair from the Record Sheet 3-1.
Selection of the Weight Set/Pair on the Retaining Ring Flange (36 Bolt Flange) ** ON A/C NOT FOR ALL The center line must be within 7.5 degrees of the Trim Phase Angle (TP).
(d) Calculate the trim balance weight positions with the center line and the number of weights or the number of hole pitches.
Write the positions on the Record Sheet 3-2.
(3) Make sure that the following condition is satisfactory:
(a) Two or more trim balance weights are not installed at one bolt hole.
(4) If the condition in step (3) is satisfactory, this SUBTASK is completed. Go to step R.
(5) If the condition in step (3) is not satisfactory, go to step (1) and use other weight set and/or weight pairs.
P. Calculate the part numbers and the positions of the trim balance weights which are to be installed on the front blade retaining ring flange (36 bolt flange) with the computer program (Method 2)
(1) Calculate with the one shot trim balance program, IAE1J12310 PROGRAM-TRIM BALANCE.
(2) Make sure that the remaining unbalance is not more than 0.5 oz.in.
(3) Write the calculated result on the Record Sheet 3-2.
Subtask 71-00-00-420-071-A ** ON A/C NOT FOR ALL (1) Calculate with the one shot trim balance program, IAE1J12310 PROGRAM-TRIM BALANCE.
(2) Make sure that the remaining unbalance is not more than 0.5 oz.in.
(3) Write the calculated result on the Record Sheet 3-2.
Q. Install the Trim Balance Weights to the Front Blade Retaining Ring
(2) Install the trim balance weight (1), (2), (3) or (4) at the bolt hole with the bolt (6).
(a) Use the trim balance weight of which part number is given in the Record Sheet 3-2.
(b) Identify the trim balance weight with the mark written on the weight.
(3) TORQUE the bolt (6) to between 220 and 180 lbf.in (2.49 and 2.03 m.daN ) (Ref. AMM TASK 70-23-11-911-013).
Subtask 71-00-00-420-080-A ** ON A/C NOT FOR ALL NOTE: Do steps (1) thru (3) for one bolt hole at a time. Do these steps until you install all the trim balance weights.
(1) Remove the bolt (6) from one of the bolt holes, where the trim balance weights are to be installed, given in the Record Sheet 3-2. (2) Install the trim balance weight (1), (2), (3) or (4) at the bolt hole with the bolt (6).
(a) Use the trim balance weight of which part number is given in the Record Sheet 3-2.
(b) Identify the trim balance weight with the mark written on the weight.
(3) TORQUE the bolt (6) to between 220 and 180 lbf.in (2.49 and 2.03 m.daN )
(Ref. AMM TASK 70-23-11-911-013). R. Install the Inlet Cone (7) and Inlet Cone Fairing (8)
(Ref. AMM TASK 72-38-11-400-010)
(1) Install the trim balance weights (10), (11), (12) and/or (13), if they were removed in step K, the inlet cone and the inlet cone fairing in their initial positions.
Subtask 71-00-00-942-059-A ** ON A/C NOT FOR ALL (Ref. AMM TASK 72-38-11-400-010)
(1) Install the trim balance weights (10), (11), (12) and/or (13), if they were removed in step K, the inlet cone and the inlet cone fairing in their initial positions.
S. Remove the Ground Support Equipment.
(1) Remove the workmat from the air intake cowl.
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).
Subtask 71-00-00-750-076-A ** ON A/C NOT FOR ALL (1) Remove the workmat from the air intake cowl.
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).
T. Do a Vibration Survey Test after Unbalance Correction
(2) If the N1 order vibration peak amounts are in limits, complete this TASK (Test No. 9).
(3) If the N1 order vibration peak amounts are not in limits do these:
(a) Do SUBTASK 71-00-00-710-139 to measure the vibration amplitude (U), the phase angle (A). Write them and N1 speed on record Sheet 1.
(b) Do step C thru step U.
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.
(1) Do Test No. 8 (Ref. AMM TASK 71-00-00-700-022) and make sure that the vibration is in the limits listed in (Ref. AMM TASK 71-00-00-860-010) engine operation limits, guidelines and special procedures, section "Vibration Limits and Fan Trim Balance Vibration Guidelines". (2) If the N1 order vibration peak amounts are in limits, complete this TASK (Test No. 9).
(3) If the N1 order vibration peak amounts are not in limits do these:
(a) Do SUBTASK 71-00-00-710-139 to measure the vibration amplitude (U), the phase angle (A). Write them and N1 speed on record Sheet 1.
(b) Do step C thru step U.