Operational Check of CVR and CVR-Channel Recording

TASK 23-71-00-710-001-A
Operational Check of CVR and CVR-Channel Recording

WARNING: MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.

NOTE: This procedure is applicable to the Cockpit Voice Recorder (CVR) and the Solid State Cockpit Voice Recorder (SSCVR).

NOTE: For this procedure, you must make sure that the PARK BRK control handle is in the ON position (accumulator pressure pointer on the triple indicator is in the green range).

ZONE: 210

1. Reason for the Job
Refer to the MPD TASK: 237100-01
OPERATIONAL CHECK OF CVR AND CVR-CHANNEL RECORDING
To do a check of the operation of the CVR.
To do a check of the recording of the communications from the CAPT, F/O and third occupant stations and the CVR microphone.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	HEADSET 600 OHMS
No specific	1	MICROPHONE 150 OHMS - HAND

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD

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 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)

3. Job Set-up
Subtask 23-71-00-860-051-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) On the Audio Control Panels (ACP) of the CAPT, F/O and third occupant stations, make sure that:

The INT/RAD selector switch is in the neutral position.
The green lines of all the transmission keys are off.
All the reception pushbutton switches are pushed (no reception).

(3) Make sure that all the boomsets are disconnected from the crew stations.
(4) Make sure that the PARK BRK control handle is in the ON position.
(5) Make sure that the aircraft is in the ground configuration.
(6) Make sure that the engine shutdown occurred five minutes or more before you do this procedure.
(7) On maintenance panel 50VU, connect the HEADSET 600 OHMS to the CVR/HEADSET connector.
(8) Connect the MICROPHONE 150 OHMS - HAND to the HAND MIC connectors of the CAPT, F/O and third occupant stations.

Subtask 23-71-00-865-050-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	COM/CVR/SPLY	2RK	E14
49VU	COM/CVR/CTL	4RK	E13
** ON A/C NOT FOR ALL
49VU	COM/CVR/SPLY	23RK	E14
49VU	COM/CVR/CTL	26RK	E13
** ON A/C NOT FOR ALL
49VU	RCDR1 CVR&FDR	40TU	E14
49VU	RCDR CTL	41TU	E13

4. Procedure
Subtask 23-71-00-710-050-A ** ON A/C NOT FOR ALL

A. Test of the CVR

NOTE: You can use the HEADSET 600 OHMS with the jack (22RK) as an alternative to the cockpit loudspeakers.

NOTE: Before this test, you can hear the frequency shift keying-signal that gives an audio signal at intervals of four seconds. The Flight Data Interface Unit (FDIU) (or Flight Data Interface and Management Unit (FDIMU)) gives this frequency shift keying-signal for the synchronization of the SSCVR clock with the Solid State Flight Data Recorder (SSFDR). This audio signal operates independently from the test of the CVR.

NOTE: During the test, if there is an acoustic feedback (Larsen effect), we recommend that you do the test of the CVR with the 22RK jack headset.

For this test, make sure that the PARK BRK control switch (on RUD TRIM/PARKING BRK panel 110VU) is in the OFF position.
Before you set the parking brake to the OFF position, make sure that the wheel chocks are installed on the MLG wheels.
After the test of the CVR, make sure that you set the parking brake back to the ON position.

NOTE: If no headset is available on the aircraft, to decrease the Larsen effect you can put your hand on the cockpit microphone.

ACTION	RESULT
1.On overhead control and indicating panel 21VU: Push the RCDR/GND CTL pushbutton switch.	On the RCDR/GND CTL pushbutton switch: The blue ON legend comes on.
2.Speak in the cockpit.	You can hear your voice from the CVR microphone in the headset connected to the 22RK jack.
3.On overhead control and indicating panel 21VU: Push and hold the RCDR/CVR TEST pushbutton switch.	At the CAPT and F/O stations: You can hear a test tone in the cockpit loudspeakers. NOTE: At the F/O station only, there can be an acoustic interference during the test, but this does not make the removal of the CVR necessary.
4.On overhead control and indicating panel 21VU: Release the RCDR/CVR TEST pushbutton switch.	You cannot hear the test tone.
5.On overhead control and indicating panel 21VU: Release the RCDR/GND CTL pushbutton switch.	On the RCDR/GND CTL pushbutton switch: The blue ON legend goes off.

Subtask 23-71-00-710-050-D ** ON A/C NOT FOR ALL

A. Test of the CVR

NOTE: You can use the HEADSET 600 OHMS with the jack (22RK) as an alternative to the cockpit loudspeakers.

NOTE: Before this test, you can hear the frequency shift keying-signal that gives an audio signal at intervals of four seconds. The Flight Data Interface Unit (FDIU) (or Flight Data Interface and Management Unit (FDIMU)) gives this frequency shift keying-signal the synchronization of the SSCVR clock with the Solid State Flight Data Recorder (SSFDR). This audio signal operates independently from the test of the CVR.

NOTE: During the test, if there is an acoustic feedback (Larsen effect), we recommend that you do the test of the CVR with the 22RK jack headset.

NOTE: If no headset is available on the aircraft, to decrease the Larsen effect you can put your hand on the cockpit microphone.

NOTE: During the test, you can hear your voice from the headset or from the cockpit loudspeakers.

ACTION	RESULT
1.On overhead control and indicating panel 21VU: Push the RCDR/GND CTL pushbutton switch.	On the RCDR/GND CTL pushbutton switch: The blue ON legend comes on.
2.Speak in the cockpit.	You can hear your voice from the CVR microphone in the headset connected to the 22RK jack.
3.On overhead control and indicating panel 21VU: Push and hold the RCDR/CVR TEST pushbutton switch.	At the CAPT (F/O or third occupant) station: You can hear a test tone in the cockpit loudspeakers or the headset. NOTE: At the F/O station only, there can be an acoustic interference during the test, but this does not make the removal of the CVR necessary.
4.On overhead control and indicating panel 21VU: Release the RCDR/CVR TEST pushbutton switch.	You cannot hear the test tone.
5.On overhead control and indicating panel 21VU: Release the RCDR/GND CTL pushbutton switch.	On the RCDR/GND CTL pushbutton switch: The blue ON legend goes off.

Subtask 23-71-00-710-055-B

B. Test of the CVR Channel Recording with the Hot-Mike Function

This procedure is applicable to the CVR supplied with 115VAC or 28VDC.

For this procedure:

Make sure that all the boomsets are disconnected.
Use only the HEADSET 600 OHMS on maintenance panel 50VU.
Make sure that the INT/RAD selector switch is set to the neutral position.

NOTE: This test is applicable to the CAPT station. To do this test on the other stations, you can use the indications between the parentheses.

ACTION	RESULT
1.On overhead control and indicating panel 21VU: Push the RCDR/GND CTL pushbutton switch.	On the RCDR/GND CTL pushbutton switch: The blue ON legend comes on.
2.Speak in the cockpit.	You can hear your voice from the CVR microphone in the CVR headset.
3.Put a cover on the CVR microphone.
Speak in the cockpit.	You cannot hear your voice from the CVR microphone in the CVR headset.
4.On the CAPT (F/O or third occupant) ACP: Set the INT/RAD selector switch to the neutral position.
5.On the CAPT (F/O or third occupant) station: Connect the MICROPHONE 150 OHMS - HAND to panel 17VU (16VU or 62VU). Push the Push-to-Talk (PTT) switch of the MICROPHONE 150 OHMS - HAND.
Speak in the MICROPHONE 150 OHMS - HAND.	You can hear your voice from the hand microphone in the CVR headset.
6.On the CAPT (F/O or third occupant) station: Release the PTT switch of the MICROPHONE 150 OHMS - HAND.
Disconnect the MICROPHONE 150 OHMS - HAND from panel 17VU (16VU or 62VU).
7.Remove the cover from the CVR microphone.
8.On overhead control and indicating panel 21VU: Release the RCDR/GND CTL pushbutton switch.	On the RCDR/GND CTL pushbutton switch: The blue ON legend goes off.

5. Close-up
Subtask 23-71-00-860-050-A

A. Put the aircraft back to its initial configuration.
(1) On the ACPs of the CAPT, F/O and third occupant stations, make sure that:

The INT/RAD selector switch is in the neutral position.
The green lines of all the transmission keys are off.
All the reception pushbutton switches are pushed (no reception).

(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 05:29:56 UTC