TAP Test of Engine Fan Blades [IAE]

TASK 72-00-00-200-011-A
TAP Test of Engine Fan Blades

ZONE: 400

1. Reason for the Job
Refer to the MPD TASK: 723100-I3
TAP TEST OF ENGINE FAN BLADES
This task gives the procedure for the transient acoustic propagation test of the LP compressor fan blades.
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)
IAE2R18901	1	TEST SET - TRANSIENT ACOUSTIC PROPAGATION
IAE2R18902	1	TEST BLOCK-TRANSIENT ACOUSTIC PROPAGATION
IAE2R19921	2	TEST SET - TRANSIENT ACOUSTIC PROPAGATION

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V06-148)	Ultrasonic Couplant

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS

D. Referenced Information

REFERENCE	DESIGNATION
TASK 72-31-11-000-010-B	Removal of the LP Compressor Fan Blades
EM 720000
Transient Acoustic Propagation (TAP) Test Set
Probe Position during TAP Test
LP Compressor Fan Blade TAP-Test Inspection Record Proforma

3. Job Set-up
Subtask 72-00-00-941-096-A ** ON A/C NOT FOR ALL

A. 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 72-00-00-941-095-A ** ON A/C NOT FOR ALL

B. Put the ground support equipment in to position.
(1) Put the ACCESS PLATFORM 1M(3 FT) in position.
(2) Put the MAT - WORK in position.

NOTE: Make sure that the red warning pennants of the workmat can be seen external of the aircraft. Make sure the workmat has sufficient dimensions to give full protection to the lower half of the fan case surface.

4. Procedure
Subtask 72-00-00-480-070-A ** ON A/C NOT FOR ALL

A. Install the Support Equipment

CAUTION: THE TAP TEST SET IS A SENSITIVE ACOUSTIC INSTRUMENT. YOU MUST BE CAREFUL WITH THE TAP TESTER TO MAKE SURE THAT THE TAP TESTER CONTINUES TO GIVE SATISFACTORY OPERATION.

(1) Prepare the IAE2R18901 TEST SET - TRANSIENT ACOUSTIC PROPAGATION or the IAE2R19921 TEST SET - TRANSIENT ACOUSTIC PROPAGATION, for use as given in the Users Guide.

Subtask 72-00-00-730-050-A ** ON A/C NOT FOR ALL

B. Do a battery check of the TAP tester:
(1) Make sure that the display does not show the message LOW BATTERY.

NOTE: The battery capability gives eight hours continuous use before a recharge is necessary.

NOTE: A charge time of 16 hours is required for every eight hours use.

NOTE: The battery life is 500 charging cycles, which is approximately 18 months if charged daily.

NOTE: If the battery charge is not sufficient for your operation or if the TAP tester does not hold its charge well, a modification is available to increase the battery capability. A TAP tester which has this modification does not have the multi-pin battery connector, but a larger version of the probe socket. Consult your IAE representative if you require this modification.

Subtask 72-00-00-730-051-A ** ON A/C NOT FOR ALL

C. Do a system check of the TAP tester:

Transient Acoustic Propagation (TAP) Test Set ** ON A/C NOT FOR ALL

CAUTION: EACH TAP TESTER IS ISSUED WITH A PROBE THAT IS ELECTRONICALLY MATCHED TO THE TAP TESTER. DO NOT CHANGE PROBES WITH ONE MATCHED TO ANOTHER UNIT AS THIS CAN CAUSE ACCEPTANCE OF REJECTABLE BLADES.

(1) Connect the probe to the tester.

NOTE: Make sure that the probe does not make contact with the blades.

(2) Press the ON switch. The display shows RRM THOR UNIT.

NOTE: The message RRM THOR UNIT shows that no pass/fail value has been pre-programmed in to the tester.

(3) Press the MENU switch. The display shows SYSTEM TEST.
(4) Press the EXE switch. The display shows SYSTEM OK.

NOTE: If the display shows a value, the probe has been damaged. You must replace the probe as soon as possible and do the system check again.

(5) Press the OFF switch to turn the tester off.

NOTE: This step is necessary to disable the system check.

Subtask 72-00-00-720-050-A ** ON A/C NOT FOR ALL

D. Do a functional check of the TAP test set:
(1) Apply a small quantity (approximately pea sized) of Ultrasonic Couplant (Material No.V06-148) to the plastic insert in the IAE2R18902 TEST BLOCK-TRANSIENT ACOUSTIC PROPAGATION or the test block a part of IAE2R19921 TEST SET - TRANSIENT ACOUSTIC PROPAGATION.
(2) Put the TAP test block on a table or a flat surface. Attach the probe to the plastic insert. Make sure that the probe is in the center of the plastic insert and that ultrasonic couplant has not been put on to the metal around the plastic insert.
(3) Press the ON switch. The display shows RRM THOR UNIT.
(4) Press the EXE switch.

CAUTION: DO NOT HOLD THE TAP TEST BLOCK WHEN YOU READ THE VALUE ENGRAVED ON THE SIDE OF THE TEST BLOCK. YOUR HAND WILL ABSORB SOME OF THE SOUND PULSE PRODUCING A FASTER DECAY RATE AND GIVE READINGS OUTSIDE THE RANGE ENGRAVED ON THE TEST BLOCK.

(a) Press the EXE switch. The display shows a value. Make sure that the value shown on the display is within the range of the value engraved on the side of the TAP test block.

NOTE: If you cannot get the correct value, clean the block and do the functional check again. If you cannot get the correct value after three tries the system has failed. If you get another error message, consult the USER GUIDE.

NOTE: If the values shown are more than the value engraved on the side of the TAP test block, make sure that the Tufnol base has not been bonded to the test block and that the base is free to turn.

NOTE: If the Tufnol base is tight on the test block the base will absorb some of the sound pulse which causes a faster decay rate. If necessary, the Tufnol base can be removed and the fit loosened by machining out the inside diameter.

NOTE: Do not remove the Tufnol base for the functional check, because different types of work surface will absorb the changing amounts of sound. This can cause faster and inconsistent decay rates.

Subtask 72-00-00-280-064-A ** ON A/C NOT FOR ALL

E. Do an Inspection of the LP Compressor Fan Blades

Probe Position during TAP Test ** ON A/C NOT FOR ALL

(1) Do a TAP-test inspection at 6 o'clock position. Lightly move the blade radially in both directions to ensure that the LP compressor fan blade moves.
(2) Apply a small quantity (approximately pea sized) of Ultrasonic Couplant (Material No.V06-148) to the lower convex airfoil adjacent to the annulus filler line.
(3) Attach the probe to the No. 1 LP compressor fan blade.
(4) LP compressor fan blade recommendations

CAUTION: DO NOT HOLD THE LP COMPRESSOR FAN BLADE WHEN YOU READ THE VALUE. YOUR HAND WILL ABSORB SOME OF THE SOUND PULSE WHICH CAUSES A FASTER DECAY RATE.

CAUTION: MAKE SURE THAT NO LEADING EDGE AND/OR TRAILING EDGE PROTECTION IS INSTALLED WHEN YOU READ THE VALUE. THE PROTECTION WILL ABSORB SOME OF THE SOUND PULSE WHICH CAUSES A FASTENER DECAY RATE.

(a) Press the ON switch.
(5) Press the EXE switch.
(a) Press the EXE switch. The display will show the value or message in approximately four seconds.

NOTE: If the display shows the message COUPLING FAILURE, apply more Ultrasonic Couplant (Material No.V06-148) and do the inspection again.

(6) If TAP-test display value is less than 700 dB/sec., accept the LP compressor fan blade.
(7) If TAP-test display value is more than 700 dB/sec. but less than 800 dB/sec., the LP compressor fan blades can stay in use for further five flight cycles. Reject the fan blades after five flight cycles.
(8) If the TAP-test display value is more than 800 dB/sec., reject the LP compressor fan blade.
(9) Remove any LP compressor fan blade rejected from the LP compressor fan disk (Ref. AMM TASK 72-31-11-000-010) or (Ref. AMM TASK 72-31-11-000-010) and repeat the TAP-test inspection on a workbench or hard surface.
(a) If the value by the repeat TAP-test inspection is less than 700 dB/sec., accept the LP compressor fan blade.
(b) If the value by the repeat TAP-test inspection is more than 700 dB/sec. again, send the LP compressor fan blade to an overhaul shop and carry out a C-scan inspection EM 720000. Supply the results to IAE Technical Services.
(10) Complete the LP compressor fan blade TAP-Test Inspection Record Proforma

LP Compressor Fan Blade TAP-Test Inspection Record Proforma ** ON A/C NOT FOR ALL

NOTE: If LP compressor fan blades have been removed from the LP compressor fan disk then record P/N and S/N details on the proforma. If LP compressor fan blades have not been removed from the LP compressor fan disk, P/N and S/N are not required.

NOTE: Supply one copy of the proforma to your local IAE representative. Keep one copy for your maintenance records.

(11) Attach the probe to the No. 2 LP compressor fan blade.
(12) Repeat step (4) thru (9).
(13) Do a test of the remaining LP compressor fan blades. Repeat step (4) thru (9).

5. Close-up
Subtask 72-00-00-942-056-A ** ON A/C NOT FOR ALL

A. Remove the ground support equipment.
(1) Remove the workmat.
(2) Remove the access platform.
(3) Remove the warning notices.

[Rev.10 from 2021] 2026.04.01 13:00:43 UTC