Removal of the Temperature Sensors

TASK 21-63-17-000-001-A
Removal of the Temperature Sensors

FIN: 21HK
FIN: 22HK
FIN: 23HK

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	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [22HK] (TEMP SENSOR FWD CAB)
231DC
FOR [23HK] (TEMP SENSOR AFT CAB)
251CC
251EC

C. Referenced Information

REFERENCE	DESIGNATION
Temperature Sensors 21HK (22HK,23HK). ** ON A/C NOT FOR ALL
Temperature Sensors 21HK (22HK,23HK). ** ON A/C NOT FOR ALL
FOR [21HK] (SENSOR-TEMPERATURE, COCKPIT or TEMP SENSOR CKPT)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
FOR [22HK] (TEMP SENSOR FWD CAB)
FOR [23HK] (TEMP SENSOR AFT CAB)
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 25-23-41-000-001-A	Removal of the Ceiling Panels

3. Job Set-up
Subtask 21-63-17-861-050-B

A. Aircraft Maintenance Configuration

(1) FOR [21HK] (SENSOR-TEMPERATURE, COCKPIT or TEMP SENSOR CKPT)
Make sure the aircraft electrical circuits are de-energized (Ref. AMM TASK 24-41-00-862-002).
(a) Put a warning notice in position to tell persons not to energize the aircraft electrical
circuits.
(2) FOR [22HK] (TEMP SENSOR FWD CAB), [23HK] (TEMP SENSOR AFT CAB)
Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 21-63-17-865-053-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 23HK (TEMP SENSOR AFT CAB) FOR FIN: 22HK (TEMP SENSOR FWD CAB)
49VU	AIR COND/TEMP CTL/SYS 1 CHAN B/28VDC	52HH	D08
** ON A/C NOT FOR ALL
122VU	AIR COND/ZONE TEMP CTL/28VDC/SYS2	4HK	V20
122VU	AIR COND/ZONE TEMP CTL/28VDC/SYS1	3HK	V19
122VU	AIR COND/ZONE TEMP CTL/115VAC/SYS2	2HK	V18
122VU	AIR COND/ZONE TEMP CTL/115VAC/SYS1	1HK	V17
** ON A/C NOT FOR ALL
122VU	AIR COND/TEMP CTL SYS 2/CHAN A/115VAC	53HH	W22
122VU	AIR COND/TEMP CTL SYS 2/CHAN A/28VDC	55HH	W21
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 2/CHAN B/28VDC	56HH	Y21
122VU	AIR COND/TEMP CTL SYS 2/CHAN B/115VAC	54HH	Y20
122VU	AIR COND/TEMP CTL SYS 1/CHAN B/115VAC	50HH	Y18

Subtask 21-63-17-010-050-B ** ON A/C NOT FOR ALL

C. Get Access
(1) For the Cockpit Temperature Sensor

(a) FOR [21HK] (SENSOR-TEMPERATURE, COCKPIT or TEMP SENSOR CKPT)
1 Remove the screws (5) and the grill (6).

WARNING: MAKE SURE THAT NO AC OR DC POWER IS CONNECTED TO THE AIRCRAFT ELECTRICAL CIRCUITS. THERE IS A RISK OF ELECTROCUTION IF THE AC OR DC POWER STAYS CONNECTED.

2 Open the circuit breaker panel (1) 121VU.
(2) For the Cabin Temperature Sensors

(a) FOR [22HK] (TEMP SENSOR FWD CAB), [23HK] (TEMP SENSOR AFT CAB)
1 Remove the cabin ceiling panels (Ref. AMM TASK 25-23-41-000-001),

a FOR [22HK] (TEMP SENSOR FWD CAB)
231DC.

b FOR [23HK] (TEMP SENSOR AFT CAB)
251CC.

Subtask 21-63-17-010-050-D ** ON A/C NOT FOR ALL

C. Get Access
(1) For the Cockpit Temperature Sensor

(a) FOR [21HK] (SENSOR-TEMPERATURE, COCKPIT or TEMP SENSOR CKPT)
1 Remove the screws (5) and the grill (6).

WARNING: MAKE SURE THAT NO AC OR DC POWER IS CONNECTED TO THE AIRCRAFT ELECTRICAL CIRCUITS. THERE IS A RISK OF ELECTROCUTION IF THE AC OR DC POWER STAYS CONNECTED.

(b) Open the circuit breaker panel (1) 121VU.
(2) For the Cabin Temperature Sensors

(a) FOR [22HK] (TEMP SENSOR FWD CAB), [23HK] (TEMP SENSOR AFT CAB)
1 Remove the cabin ceiling panels (Ref. AMM TASK 25-23-41-000-001),

a FOR [22HK] (TEMP SENSOR FWD CAB)
231DC.

b FOR [23HK] (TEMP SENSOR AFT CAB)
251EC.

4. Procedure
Subtask 21-63-17-020-053-B

A. Removal of the Cockpit Temperature Sensor 21HK
(1) Disconnect the electrical connector (2).
(2) Remove the isolation material (8).
(3) Put blanking caps on the disconnected electrical connectors.
(4) Remove the screws (3) and the sensor (4).

Subtask 21-63-17-020-050-B

B. Removal of the Cabin Temperature Sensor

(1) FOR [22HK] (TEMP SENSOR FWD CAB), [23HK] (TEMP SENSOR AFT CAB)
(a) Disconnect the electrical connector (26).
(b) Put blanking caps on the disconnected electrical connectors.
(c) Release the quick-release fasteners (29) and remove the front panel (24) together with the temperature sensor (27).
(d) Remove the nuts (22), the washers (23), the screws (25), the temperature sensor (27) and the gasket (28).

[Rev.10 from 2021] 2026.04.01 04:52:58 UTC