Blending of the Struts Pads [CFML]

TASK 72-24-03-300-805-A
Blending of the Struts Pads

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 210
ZONE: 400

1. Reason for the Job
This repair procedure gives instructions to do the blend repair on the right strut 1 pad, on the left strut 1 pad, on the right strut 5 pad and on the left strut 5 pad.
Ref Fig N_MP_722403_991_03400—Strut 1 and Strut 5 Pads.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP1041)	isopropyl alcohol
No specific	S1093 Titanium Alloys Etchant

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 72-24-03-210-801-A	Visual Inspection of the Strut 1
TASK 72-24-03-210-802-A	Visual Inspection of the Strut 5
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
SPM 702123
SPM 703200
SPM 704111
SPM 704112
SPM 705311
Strut 1 and Strut 5 Pads

3. Job Set-up
Subtask 72-24-03-941-065-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put the WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch and
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put the WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 72-24-03-010-079-A

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR.
(2) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.

Subtask 72-24-03-040-065-A

C. Deactivation of the Thrust Reverser (T/R) System for Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the T/R system for maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 72-24-03-010-080-A

D. Get Access
(1) Open the T/R cowl doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL, 452AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL, 462AR.

Subtask 72-24-03-990-050-A

E. Applicable Parts
(1) The subsequent table gives a list of the part numbers that are applicable to this repair. All part numbers are applicable to all paragraphs unless specified differently.

Part Number	Service Bulletin	CSN	Designation
362-089-255-0	-	(87-220; 72-00-00)	RH strut 1 pad
362-082-855-0	-	(87-180; 72-00-00)	LH strut 1 pad
362-082-955-0	-	(18-330; 72-00-00)	RH strut 5 pad
362-083-055-0	-	(36-620; 72-00-00)	LH strut 5 pad

Table - Applicable Parts

4. Procedure
Subtask 72-24-03-220-057-A

A. Dimensional Information

Description	Minimum In-Process Dimension	Maximum In-Process Dimension	Minimum Finish Dimension	Maximum Finish Dimension	Reference Dimension
DIM. A	-	-	25 mm (0.98 in.)	-	-
DIM. B	-	-	45 mm (1.77 in.)	-	-
DIM. C	-	-	30 mm (1.18 in.)	-	-
DIM. D	-	-	117 mm (4.61 in.)	-	-
DIM. E	-	-	21 mm (0.83 in.)	-	-
DIM. F	-	-	39 mm (1.54 in.)	-	-
DIM. G	-	-	61 mm (2.40 in.)	-	-
DIM. H	-	-	111 mm (4.37 in.)	-	-
DIM. J	-	-	136 mm (5.35 in.)	-	-
DIM. K	-	-	26 mm (1.02 in.)	-	-
DIM. L	-	-	17 mm (0.67 in.)	-	-
DIM. M	-	-	38 mm (1.50 in.)	-	-
DIM. N	-	-	57 mm (2.24 in.)	-	-
DIM. P	-	-	77 mm (3.03 in.)	-	-
DIM. Q	-	-	165 mm (6.50 in.)	-	-
DIM. R	-	-	88 mm (3.46 in.)	-	-
DIM. S	-	-	128 mm (5.04 in.)	-	-
DIM. T	-	-	60 mm (2.36 in.)	-	-
DIM. U	-	-	14 mm (0.55 in.)	-	-
DIM. V	-	-	110 mm (4.33 in.)	-	-
DIM. W	-	-	23 mm (0.91 in.)	-	-
DIA X	-	-	45 mm (1.77 in.)	-	-
DIM. Y	-	-	49 mm (1.93 in.)	-	-
DIM. Z	-	-	71 mm (2.80 in.)	-	-
DIM. AA	-	-	8 mm (0.31 in.)	-	-
DIM. AB	-	-	50 mm (1.97 in.)	-	-
DIM. AC	-	-	118 mm (4.65 in.)	-	-
DIM. AD	-	-	53 mm (2.09 in.)	-	-
DIM. AE	-	-	103 mm (4.06 in.)	-	-
DIM. AF	-	-	132 mm (5.20 in.)	-	-
DIM. AG	-	-	80 mm (3.15 in.)	-	-
DIM. AH	-	-	105 mm (4.13 in.)	-	-
DIM. AJ	-	-	58 mm (2.28 in.)	-	-
DIM. AK	-	-	90 mm (3.54 in.)	-	-
DIM. AL	-	-	35 mm (1.38 in.)	-	-
DIM. AM	-	-	82 mm (3.23 in.)	-	-
DIM. AN	-	-	72 mm (2.83 in.)	-	-
DIM. AP	-	-	65 mm (2.56 in.)	-	-
DIM. AQ	-	-	102 mm (4.02 in.)	-	-
DIM. AR	-	-	130 mm (5.12 in.)	-	-
DIM. AS	-	-	28 mm (1.10 in.)	-	-
DIM. AT	-	-	62 mm (2.44 in.)	-	-
DIM. AU	-	-	-	0.6 mm (0.024 in.)	-

Table - Dimensional Information

Subtask 72-24-03-210-056-A

B. Visual Inspection of the Struts Pads
(1) Do a visual inspection of the strut 1 and strut 5 pads. Maximum three blending are permitted on each struts pads.

Subtask 72-24-03-320-051-A

C. Blending of the Struts Pads

WARNING: USE PERSONAL PROTECTION EQUIPMENT. METAL PARTICLES CAN CAUSE DAMAGE, INJURY OR IRRITATION.

WARNING: DO NOT LET TITANIUM DUST COLLECT. TITANIUM DUST IS FLAMMABLE. DO NOT USE WATER TO EXTINGUISH A TITANIUM FIRE. EXTINGUISH WITH AN APPROVED CHEMICAL FOR METAL FIRES.

CAUTION: WHEN YOU DO THE BLENDING, REMOVE ONLY THE MINIMUM QUANTITY OF MATERIAL NECESSARY TO REMOVE THE DEFECT. IF YOU REMOVE TOO MUCH MATERIAL, DAMAGE TO THE PART CAN OCCUR.

(1) Refer to Para 4.A. ”Dimensional Information” and do the blending of the struts pads as follows:
(a) Alternative procedure available. Remove the indication by hand blending SPM 704111.
(b) Alternative procedure. Remove the indication by power blending SPM 704112.
(c) If the minimum acceptable distance between two repaired areas is less than 40 times the DIM. AU, mix them to get only one repaired area.
(d) Make sure that the blended areas have a smooth contour into the adjacent areas to keep a correct airflow.

Subtask 72-24-03-110-052-A

D. Clean the Struts Pads
(1) Clean the strut 1 and strut 5 pads using isopropyl alcohol (Material No.CP1041) SPM 702123.

Subtask 72-24-03-110-053-A

E. Local Swab Etching of the Repaired Areas
(1) Do a local swab etching of the repaired areas with S1093 Titanium Alloys Etchant SPM 705311.

Subtask 72-24-03-230-054-A

F. Fluorescent Penetrant Inspection (FPI) of the Repaired Areas
(1) Do a FPI of the repaired areas SPM 703200.
(a) Use sensitivity level 2.
(b) Indications more than 0.0118 in. (0.30 mm) are not permitted.
(c) Linear indications are not permitted.

NOTE: Linear indications are indications that are at least four times longer than they are wide.

Subtask 72-24-03-210-057-A

G. Visual Inspection of the Struts Pads
(1) Do a visual inspection of the struts pads. (Ref. AMM TASK 72-24-03-210-801) for strut 1 pads or to (Ref. AMM TASK 72-24-03-210-802) for strut 5 pads.

5. Close-up
Subtask 72-24-03-410-075-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the T/R cowl doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL, 452AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL, 462AR.

Subtask 72-24-03-440-063-A

B. Do the reactivation of the T/R system after maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 72-24-03-410-076-A

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR.
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR.
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 13:04:05 UTC