Detailed Inspection of Igniter Plug (131-9(A))

TASK 49-41-41-220-001-A
Detailed Inspection of Igniter Plug (131-9(A))

WARNING: DO NOT TOUCH THE APU UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS WHEN YOU DO THE MAINTENANCE TASK(S).

WARNING: DISCONNECT THE LOW-TENSION ELECTRICAL SUPPLY 6 MINUTES BEFORE YOU START WORK ON THE IGNITION SYSTEM. THE HIGH CURRENT AND VOLTAGE WHICH ARE USED IN THE IGNITION SYSTEM CAN KILL YOU.

ZONE: 315
ZONE: 316

1. Reason for the Job
Refer to the MPD TASK: 494000-B2
DETAILED INSPECTION OF IGNITER PLUG
2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
315	TAIL CONE APU AND ACCESSORY COMPARTMENT
316	TAIL CONE APU AND ACCESSORY COMPARTMENT

B. Referenced Information

REFERENCE	DESIGNATION
TASK 49-41-41-000-005-A	Removal of the Igniter Plug (131-9(A))
TASK 49-41-41-400-004-A	Installation of the Igniter Plug (131-9(A))
Igniter Plug (131-9(A))

3. Job Set-up
Subtask 49-41-41-020-055-A ** ON A/C NOT FOR ALL

A. Remove the igniter plug (Ref. AMM TASK 49-41-41-000-005).

4. Procedure
Subtask 49-41-41-220-050-A ** ON A/C NOT FOR ALL

A. Detailed Inspection of the Igniter plug

NOTE: There is only one igniter plug in this APU.

(1) Make sure that the parts retained from the removed component are clean and in the correct condition.
(2) Clean the component interfaces and the adjacent area.
(3) Do a a general visual inspection of the igniter plug for damaged or broken parts. Shake the igniter plug and listen for noise:
(a) If you can hear loose pieces or parts, the igniter plug is damaged. Replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).
(4) Examine the igniter plug for internal wear and failure:
(a) Examine the center electrode for radial cracks and wear:
1 If the center electrode is damaged, replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).
(b) Examine the inner circumference of the outer electrode for wear:
1 If there is wear on more than 90 degrees of the inner circumference, replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).
(5) Do a check of the dimensions to make sure that they are in the serviceable limits:
(a) If the dimensions are out of the limits, replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).
(6) Examine the ceramic insulator for cracks or broken area(s):
(a) If the ceramic insulator is cracked or broken, replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).
(7) Examine the outer shell for burned or flowed metal:
(a) If the outer shell is burned or flowed, replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).
(8) Make sure that the holes between the insulator and the outer shell are not clogged:
(a) If the holes are clogged, replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).
(9) Examine the igniter plug for bent or burned electrical connection:
(a) If the igniter plug electrical-connection is bent or burned, replace the igniter plug (Ref. AMM TASK 49-41-41-400-004).

5. Close-up
Subtask 49-41-41-420-055-A ** ON A/C NOT FOR ALL

A. Install Igniter Plug (Ref. AMM TASK 49-41-41-400-004).

[Rev.10 from 2021] 2026.04.01 01:30:16 UTC