Installation of the Left Ignition Lead [CFMB]

TASK 74-21-20-400-002-A
Installation of the Left Ignition Lead

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
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	WARNING NOTICE(S)
No specific	Torque wrench: range to between 37 and 33 lbf.in (0.42 and 0.37 m.daN )
No specific	Torque wrench: range to between 110 and 100 lbf.in (1.24 and 1.13 m.daN )
No specific	Torque wrench: range to between 160 and 140 lbf.in (1.81 and 1.58 m.daN )
No specific	Torque wrench: range to between 290 and 260 lbf.in (3.28 and 2.94 m.daN )

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CP1040)	methyl ethyl ketone
(Material No.CP2267)	RTV 106
(Material No.CP5070)	vaseline

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

D. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
20	O-RING	AIPC 74-21-20-01-040
10	SEAL	AIPC 74-21-20-01-060

E. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-B	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-B	Closing of the Fan Cowl Doors
TASK 74-00-00-710-043-A	Operational Test of the Ignition System
TASK 74-00-00-710-043-A-01	Operational Test of the Ignition System without CFDS
TASK 78-30-00-081-041-B	Make the Thrust Reverser Serviceable after Maintenance
TASK 78-30-00-481-041-B	Make the Thrust Reverser Unserviceable for Maintenance
TASK 78-36-00-010-040-B	Opening of the Thrust Reverser Doors
TASK 78-36-00-410-040-B	Closing of the Thrust Reverser Doors
Left Ignition Lead
Ignition Lead Assembly
Left Ignition Lead Sealant

3. Job Set-up
Subtask 74-21-20-860-051-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) On the center pedestal, on the ENG panel 115VU, make sure that a WARNING NOTICE(S) is in position to tell persons not to start the engine.
(2) On the overhead maintenance panel 50VU, make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off. Make sure that a WARNING NOTICE(S) is in position to tell persons not to energize the FADEC 1(2).
(3) Make sure that the ACCESS PLATFORM 1M(3 FT) is in position.

Subtask 74-21-20-010-059-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Make sure that the fan cowl doors are open: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Make sure that the thrust reverser doors are open: (Ref. AMM TASK 78-36-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 74-21-20-040-055-A ** ON A/C NOT FOR ALL

C. Make sure that the thrust reverser is unserviceable (Ref. AMM TASK 78-30-00-481-041).

Subtask 74-21-20-865-056-A ** ON A/C NOT FOR ALL

D. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 1000EM1 (ENGINE1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
121VU	ENGINE/IGN/ENG1/SYS A BAT	2JH1	P39
FOR FIN: 1000EM2 (ENGINE2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42
121VU	ENGINE/IGN/ENG2/SYS A BAT	2JH2	P40

4. Procedure
Subtask 74-21-20-916-051-A ** ON A/C NOT FOR ALL

A. Apply the protective treatment

CAUTION: BE CAREFUL WITH THE LEAD TO PREVENT DAMAGE TO THE CONDUIT AND INTERNAL WIRES.

(1) Remove protective caps from the electrical connectors.
(2) Apply vaseline (Material No.CP5070) to the new AIPC 74-21-20-01-040 O-RING (20).

Subtask 74-21-20-420-054-A ** ON A/C NOT FOR ALL

B. Installation of the left ignition lead.
(1) Install the new AIPC 74-21-20-01-040 O-RING (20) on the ignition lead fitting.
(2) Carefully push the ignition exciter end of the ignition lead forward through the holes in the bundle junction box cover until the flange fitting of the ignition lead is seated against the bundle junction box cover.
(3) Install the retaining plate so the angled edge points aft above the ignition lead at the aft end of the tube bundle junction box. Hand-tighten the bolt.
(4) TORQUE the bolt to between 110 and 100 lbf.in (1.24 and 1.13 m.daN )

.
(5) Engage the ignition lead into the clips on the junction box, the 6 o'clock strut, the TGB, and the fan frame.
(6) Connect the forward end of the ignition lead to the lower ignition exciter.
(7) TORQUE the ignition lead connector to between 160 and 140 lbf.in (1.81 and 1.58 m.daN )

.
(8) Install the strut fairings on both side of the tube bundle (6 o'clock position).

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

(a) Clean the area to be sealed with a clean cotton cloth made moist with methyl ethyl ketone (Material No.CP1040) . Wipe the area with a clean lint free cotton cloth before the solvent becomes gas.
(b) Apply RTV 106 (Material No.CP2267) approximately 0.020 in. (0.5080 mm) thick.

PRE SB 74-002
(9) Install the caged spring assembly to the ignition lead. Make sure that the large shoulder end of the caged spring assembly is at the contact end of the ignition lead.
(10) Install the new white chamfered silicone AIPC 74-21-20-01-060 SEAL (10) to the ignition lead. The small diameter collar of the white chamfered silicone seal must be put into the large collar of the caged spring assembly.

POST SB 74-002
(11) Install the new blue symmetrical AIPC 74-21-20-01-060 SEAL (10) on the ignition lead.
END of SB 74-002
(12) Install the ignition lead

CAUTION: DO NOT APPLY GREASE OR ANY LUBRICANT TO THE THREADS OF THE CONNECTOR ON THE IGNITION LEAD. GREASE AND LUBRICANTS WILL CAUSE DAMAGE TO THE IGNITION LEAD AND THE SPARK IGNITER.

CAUTION: MAKE SURE THAT YOUR HANDS AND TOOLS ARE CLEAN. DO NOT TOUCH THE IGNITION LEAD OR THE SPARK IGNITER WITH DIRTY OR GREASY HANDS AND TOOLS, DIRT AND GREASE WILL CAUSE DAMAGE TO THE IGNITION LEAD AND THE SPARK IGNITER.

(a) Install the ignition lead into the spark igniter, and TORQUE the coupling nut of the ignition lead to between 290 and 260 lbf.in (3.28 and 2.94 m.daN )

.
(13) Assemble the 2 piece cooling shroud onto the flange of the ignition lead and attach with the shroud clamp.
(14) TORQUE the shroud clamp to between 37 and 33 lbf.in (0.42 and 0.37 m.daN )

.
(15) Route the ignition lead along the core engine, and install it into the 2 hinged clamps. Turn the attachment bolt one-quarter turn to engage the locking feature, and continue to tighten until the ignition lead cannot be moved in the clamp.

Subtask 74-21-20-865-057-A ** ON A/C NOT FOR ALL

C. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	ENGINE/1 AND 2/IGN/SYS A	1JH	A03
FOR FIN: 1000EM1 (ENGINE1)
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41
121VU	ENGINE/IGN/ENG1/SYS A BAT	2JH1	P39
FOR FIN: 1000EM2 (ENGINE2)
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42
121VU	ENGINE/IGN/ENG2/SYS A BAT	2JH2	P40

Subtask 74-21-20-710-051-A ** ON A/C NOT FOR ALL

D. Perform an operational test of the ignition system (Ref. AMM TASK 74-00-00-710-043).

5. Close-up
Subtask 74-21-20-410-054-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser doors: (Ref. AMM TASK 78-36-00-410-040).
(3) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(4) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 74-21-20-440-053-A ** ON A/C NOT FOR ALL

B. Make the thrust reverser serviceable (Ref. AMM TASK 78-30-00-081-041).

Subtask 74-21-20-410-057-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowl doors: (Ref. AMM TASK 71-13-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 03:07:41 UTC