Removal of the Pressure Sensor

TASK 21-58-12-000-001-A
Removal of the Pressure Sensor

WARNING: MAKE SURE THAT AIR IS NOT SUPPLIED TO THE AIR CONDITIONING SYSTEM FROM THE MAIN ENGINE, THE APU OR A GROUND SOURCE. HOT COMPRESSED AIR CAN CAUSE INJURY TO PERSONNEL.

WARNING: DO NOT TOUCH THE COMPONENT UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS.

FIN: 117HW ** 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	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
191KB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 53-35-13-000-002-A	Removal of the Quick-Release Access Panels from the Belly Fairing Structure
Pressure Sensor (117HW)

3. Job Set-up
Subtask 21-58-12-861-050-A ** ON A/C NOT FOR ALL

A. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

Subtask 21-58-12-865-050-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR BLEED/X FEED/VALVE/BAT	2HV	D13
49VU	AIR COND/TEMP CTL/SYS 1 CHAN B/28VDC	52HH	D08
** ON A/C NOT FOR ALL
49VU	AIR BLEED/ENG 1/CTL	3HA1	D12
49VU	AIR BLEED/ENG 1/MONG	2HA1	D11
** ON A/C NOT FOR ALL
49VU	AIR BLEED/ENG 2/MONG	3HA2	D12
49VU	AIR BLEED/ENG 1/CTL	2HA1	D11
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	N28
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	P28
** ON A/C NOT FOR ALL
122VU	CSAS / CTRL	1HW	U17
122VU	AIR COND/TEMP CTL SYS 1/CHAN A/115VAC	49HH	X22
122VU	AIR COND/TEMP CTL SYS 1/CHAN A/28VDC	51HH	X21
122VU	AIR COND/TEMP CTL SYS 1/CHAN B/115VAC	50HH	Y18
122VU	AIR BLEED/X FEED VALVE/NORM	1HV	Z20
** ON A/C NOT FOR ALL
122VU	AIR BLEED/ENG 2/CTL	3HA2	Z23
122VU	AIR BLEED/ENG 2/MONG	2HA2	Z22
** ON A/C NOT FOR ALL
122VU	AIR BLEED/ENG 1/MONG	3HA1	Z23
122VU	AIR BLEED/ENG 2/CTL	2HA2	Z22

Subtask 21-58-12-941-050-A ** ON A/C NOT FOR ALL

C. Safety Precautions
(1) On the panel 30VU, make sure that:

The APU BLEED pushbutton switch is in the off position (the ON legend is off).
The ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are in the off position (the OFF legends are on).

(a) Put a WARNING NOTICE(S) in position to tell persons not to operate these pushbutton switches.
(2) On the HP ground connector put a warning notice in position to tell persons not to supply the ground air.

Subtask 21-58-12-010-050-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) in position at the zone 191.
(2) Remove the access panel 191KB (Ref. AMM TASK 53-35-13-000-002).

4. Procedure
Subtask 21-58-12-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Pressure Sensor

Pressure Sensor (117HW) ** ON A/C NOT FOR ALL

(1) Disconnect the electrical connector (1).
(2) Put a CAP - BLANKING on the disconnected electrical connector (1).
(3) Remove the screws (5), the washers (4), the O-ring (3) and the pressure sensor (2).
(4) Discard the O-ring (3).
(5) Put PLUG - BLANKING on the disconnected line ends.

[Rev.10 from 2021] 2026.04.02 06:48:49 UTC