Verification of Speech Intelligibility of the Passenger Address (PA) System (According to Civil Aviation Authority (CAA) Spec. 15)

TASK 23-73-00-720-002-A
Verification of Speech Intelligibility of the Passenger Address (PA) System (According to Civil Aviation Authority (CAA) Spec. 15)

1. Reason for the Job
CAA Spec.15
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	2	SOUND PRESSURE METER - 90 TO 130DB (ACCURACY 1DB)
No specific	1	TEST UNIT - TONE GENERATOR
98-04-08138	1	GENERATOR, TEST TONE
98-04-12348	1	TESTER-ACOUSTIC, CIDS
98-04-14059	1	ACOUSTIC TESTER

B. Referenced Information

REFERENCE	DESIGNATION
TASK 23-73-00-860-004-A	Passenger Address (PA) Level Adjustment via PTP
TASK 23-73-00-860-005-A	Passenger Address (PA) Level Interrogation via CFDS
TASK 23-73-00-860-009-A	Loudspeaker Volume Adjustments
TASK 23-73-00-861-001-A	Energize the Cabin Intercommunication Data System (CIDS)
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)
TASK 35-23-00-710-001-A	Operational Check of Manual Mask Release
Sound Pressure Measurement ** ON A/C NOT FOR ALL
Sound Pressure Measurement ** ON A/C NOT FOR ALL
Sound Pressure Measurement ** ON A/C NOT FOR ALL
Sound Pressure Measurement ** ON A/C NOT FOR ALL
Sound Pressure Measurement ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 23-73-00-860-138-B ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Make sure that the Cabin Intercommunication Data System (CIDS) is energized
(Ref. AMM TASK 23-73-00-861-001).
(3) Energize the passenger emergency-oxygen system
(Ref. AMM TASK 35-23-00-710-001).
(4) Make sure that the INT/RAD switch on the Audio Control Panel (ACP) is in the center position.
(5) Make sure that the INTEG LT/ MAIN PNL & PED rotary knob on pedestal panel 111VU is in the BRT position.
(6) Make sure that the cockpit door is closed.
(7) Make sure that at least one cabin door is open.
(8) Make sure that the engines are not running.
(9) On all the passenger-oxygen containers, pull out the doorstops and turn them 90 degrees to the TEST position.
(10) On the Programming and Test Panel (PTP) 110RH, set the PA-level to the basic (default) configuration
(Ref. AMM TASK 23-73-00-860-004).

NOTE: The annunciation indication and the communication go off, if there is a delay of more than 60 sec. between the test procedure steps.

Subtask 23-73-00-860-138-C ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) Make sure that the Cabin Intercommunication Data System (CIDS) is energized
(Ref. AMM TASK 23-73-00-861-001).
(3) Energize the passenger emergency-oxygen system
(Ref. AMM TASK 35-23-00-710-001).
(4) Make sure that the INT/RAD switch on the Audio Control Panel (ACP) is in the center position.
(5) Make sure that the INTEG LT/ MAIN PNL & PED rotary knob on pedestal panel 111VU is in the BRT position.
(6) Make sure that the cockpit door is closed.
(7) Make sure that a minimum of one cabin door is open.
(8) Make sure that the engines are not running.
(9) On all the passenger-oxygen containers, set the doorstops to the TEST position.
(10) On the Flight Attendant Panel (FAP) 120RH, set the announcement volume levels in all cabin zones to the basic (default) configuration.
(Ref. AMM TASK 23-73-00-860-009).

NOTE: The annunciation indication and the communication go off, if there is a delay of more than 60 sec. between the test procedure steps.

Subtask 23-73-00-865-155-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	ENGINE/2/FADEC A/AND EIU 2	2KS2	A05

Subtask 23-73-00-865-168-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	ENGINE/IGN/ENG2/SYS A BAT	2JH2	P40
121VU	ENGINE/IGN/ENG1/SYS A BAT	2JH1	P39
** ON A/C ALL
121VU	ENGINE/IGN/ENG2/SYS B	3JH2	P42
121VU	ENGINE/IGN/ENG1/SYS B	3JH1	P41

4. Procedure
Subtask 23-73-00-710-256-A ** ON A/C NOT FOR ALL

A. Verification of the correct loudspeaker operation

ACTION	RESULT
1.In the cockpit:
lift the handset from the cradle.
2.On the cockpit handset:	On all Attendant Indication Panels (AIP):
push and hold the PTT switch and make an announcement.	'PA ALL IN USE' shows.

	In the cabin, in all lavatories and at all attendant stations:
	you hear the announcement loud and clear and without distortion.

	Through the cockpit handset:
	you hear the announcement.

	On all AIPs:
put the handset back in the cradle.	'PA ALL IN USE' goes off.

Subtask 23-73-00-710-256-B ** ON A/C NOT FOR ALL

A. Verification of the correct loudspeaker operation

ACTION	RESULT
1.In the cockpit:
lift the handset from the cradle.
2.On the cockpit handset:	On all Attendant Indication Panels (AIP):
push and hold the PTT switch and make an announcement.	'DIRECT PA' shows.

	In the cabin, in all lavatories and at all attendant stations:
	you hear the announcement loud and clear and without distortion.

	Through the cockpit handset:
	you hear the announcement.

	On all AIPs:
put the handset back in the cradle.	'DIRECT PA' goes off.

Subtask 23-73-00-720-051-B ** ON A/C NOT FOR ALL

B. Measure the sound pressure level

Sound Pressure Measurement ** ON A/C NOT FOR ALL

(1) Put the cockpit handset to the Test Tone Generator:

For Becker Flugfunk handsets use TEST UNIT - TONE GENERATOR.
For Holmberg handsets use 98-04-14059 ACOUSTIC TESTER. If Holmberg 89-X handset is installed, make sure that the Acoustic Adapter (4) is attached correctly on the Aircraft Acoustic Tester.

NOTE: You can also use 98-04-08138 GENERATOR, TEST TONE for Holmco handset series 89-X and 98-04-12348 TESTER-ACOUSTIC, CIDS for Holmco handset series N40.
If you use 98-04-08138 GENERATOR, TEST TONE, follow the instructions for Becker handsets.
If you use 98-04-12348 TESTER-ACOUSTIC, CIDS, follow the instructions for Holmberg handsets.

(2) Put the microphone of the SOUND PRESSURE METER - 90 TO 130DB (ACCURACY 1DB) approx. 10 +/-0,5 cm below the first pax loudspeaker.

NOTE: The cockpit door has to be closed through the whole test.

(a) For Becker handsets, follow these instructions:

ACTION	RESULT
1.On the Test Tone Generator:	In the cabin, in all lavatories and at all attendant stations:
Set the White Noise test-tone switch to the ON postion.	You hear the test tone from all loudspeakers.
	At the Sound Pressure Meter:
	The sound pressure level must not be less than the value given in the table for the sound pressure levels. Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ON A/C NOT FOR ALL NOTE: The location of the cabin segments in relation to the seat rows shows in the CFDS/PA LEVEL REPORT. (Ref. AMM TASK 23-73-00-860-005)
2.Do a the test step again for all cabin, lavatory and attendant loudspeakers.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
3.On the Test Tone Generator:	In the cabin, all lavatories and at all attendant stations:
Set the White Noise test-tone switch to the OFF postion.	The test tone stops.

(b) For Holmberg handsets, follow these instructions:

ACTION	RESULT
1.On the Aircraft Acoustic Tester:	On the Aircraft Acoustic Tester:
Set the switch (2) to the SPK position. Set the power switch (1) to the ON position.	The light in the power switch (1) comes on. The display (3) shows SPEAKER OFF.
	In the cabin, in all lavatories and at all attendant stations:
Push the center button below the display (3) until its top row shows: SPK: NOISE. Push the right button below the display (3) until its bottom row shows: VOL: 104 dBSPL.	You hear the test tone from all loudspeakers.
	At the Sound Pressure Meter:
2.Do a check of the sound pressure level at the pax loudspeaker.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
3.Do the step 2. again for all loudspeakers in the cabin, in the lavatories and at the attendant stations.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
Set the power switch (1) to the OFF position.	The test tone stops. Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ON A/C NOT FOR ALL NOTE: The location of the cabin segments in relation to the seat rows shows in the CFDS/PA LEVEL REPORT. (Ref. AMM TASK 23-73-00-860-005)
4.On the Aircraft Acoustic Tester:	In the cabin, all lavatories and at all attendant stations:
Set the power switch (1) to the OFF position.	The test tone stops.

Subtask 23-73-00-720-051-C ** ON A/C NOT FOR ALL

B. Measure the sound pressure level

Sound Pressure Measurement ** ON A/C NOT FOR ALL

(1) Put the cockpit handset to the Test Tone Generator:

For Becker Flugfunk handsets use TEST UNIT - TONE GENERATOR.
For Holmberg handsets use 98-04-14059 ACOUSTIC TESTER. If Holmberg 89-X handset is installed, make sure that the Acoustic Adapter (4) is attached correctly on the Aircraft Acoustic Tester.

(2) Put the microphone of the SOUND PRESSURE METER - 90 TO 130DB (ACCURACY 1DB) approx. 10 +/-0,5 cm below the first pax loudspeaker.

NOTE: The cockpit door must be closed during the whole test.

(a) For Becker handsets, follow these instructions:

ACTION	RESULT
1.On the Test Tone Generator:	In the cabin, in all lavatories and at all attendant stations:
Set the White Noise test-tone switch to the ON postion.	You hear the test tone from all loudspeakers.
	At the Sound Pressure Meter:
	The sound pressure level must not be less than the value given in the table for the sound pressure levels. Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ON A/C NOT FOR ALL NOTE: The location of the cabin segments in relation to the seat rows shows in the CFDS/LSP VOLUME REPORT. (Ref. AMM D/O 23-73-00-86)
2.Do the test step again for all cabin, lavatory and attendant loudspeakers.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
3.On the Test Tone Generator:	In the cabin, in all lavatories and at all attendant stations:
Set the White Noise test-tone switch to the OFF postion.	The test tone stops.

(b) For Holmberg handsets, follow these instructions:

ACTION	RESULT
1.On the Aircraft Acoustic Tester:	On the Aircraft Acoustic Tester:
Set the switch (2) to the SPK position. Set the power switch (1) to the ON position.	The light in the power switch (1) comes on. The display (3) shows SPEAKER OFF.
	In the cabin, in all lavatories and at all attendant stations:
Push the center button below the display (3) until its top row shows: SPK: NOISE. Push the right button below the display (3) until its bottom row shows: VOL: 104 dBSPL.	You hear the test tone from all loudspeakers.
	At the Sound Pressure Meter:
2.Do a check of the sound pressure level at the pax loudspeaker.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
3.Do the step 2. again for all loudspeakers in the cabin, in the lavatories and at the attendant stations.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
Set the power switch (1) to the OFF position.	The test tone stops. Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ON A/C NOT FOR ALL NOTE: The location of the cabin segments in relation to the seat rows shows in the CFDS/LSP VOLUME REPORT. (Ref. AMM D/O 23-73-00-86)
4.On the Aircraft Acoustic Tester:	In the cabin, all lavatories and at all attendant stations:
Set the power switch (1) to the OFF position.	The test tone stops.

Subtask 23-73-00-720-051-D ** ON A/C NOT FOR ALL

B. Measurement of the sound pressure level

Sound Pressure Measurement ** ON A/C NOT FOR ALL

(1) Put the cockpit handset to the 98-04-14059 ACOUSTIC TESTER. If Holmberg 89-X handset is installed, make ACOUSTIC TESTER sure that the Acoustic Adapter (4) is attached correctly on the Aircraft Acoustic Tester.

NOTE: You can also use 98-04-12348 TESTER-ACOUSTIC, CIDS for Holmco handset series N40.
If you use this tool, follow the instructions for Holmberg handsets.

(2) Put the microphone of the SOUND PRESSURE METER - 90 TO 130DB (ACCURACY 1DB) approx. 10 +/-0,5 cm below the first PAX loudspeaker.

NOTE: The cockpit door must stay closed during the test.

ACTION	RESULT
1.On the Aircraft Acoustic Tester:	On the Aircraft Acoustic Tester:
Set the switch (2) to the SPK position. Set the power switch (1) to the ON position.	The light in the power switch (1) comes on. The display (3) shows SPEAKER OFF.
	In the cabin, in all lavatories and at all attendant stations:
Push the center button below the display (3) until its top row shows: SPK: NOISE. Push the right button below the display (3) until its bottom row shows: VOL: 104 dBSPL.	You hear the test tone from all loudspeakers.
	At the Sound Pressure Meter:
2.Do a check of the sound pressure level at the PAX loudspeaker.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
3.Do the step 2. again for all loudspeakers in the cabin, in the lavatories and at the attendant stations.	The sound pressure level must not be less than the value given in the table for the sound pressure levels.
Set the power switch (1) to the OFF position.	The test tone stops. Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ON A/C NOT FOR ALL NOTE: The location of the cabin segments in relation to the seat rows shows in the CFDS/LSP VOLUME REPORT. (Ref. AMM D/O 23-73-00-86)
4.On the Aircraft Acoustic Tester:	In the cabin, all lavatories and at all attendant stations:
Set the power switch (1) to the OFF position.	The test tone stops.

Subtask 23-73-00-720-052-A ** ON A/C NOT FOR ALL

C. Measurement of the automatic gain increase

Sound Pressure Measurement ** ON A/C NOT FOR ALL

(1) Put the microphone of the SOUND PRESSURE METER - 90 TO 130DB (ACCURACY 1DB) below the first pax loudspeaker.

NOTE: The cockpit door must be closed during the whole test.

ACTION	RESULT
1.On the Test Tone Generator:	In the cabin, in all lavatories and at all attendant stations:
select the White Noise test tone.	you hear the test tone from all loudspeakers.
	At the Sound Pressure Meter:
	the sound pressure level must not be less than the value given in the table for the sound pressure levels. Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ** ON A/C NOT FOR ALL NOTE: Before you start the next step of the test, make sure that all emergency oxygen-container doorstops are set to the test position.
2.In the cockpit, on the overhead panel 21VU:	In the cabin, in all lavatories and at all attendant stations:
lift the switch guard, push and release the MASK MAN ON pushbutton switch.	the doors of the emergency oxygen containers open to the test position.
	the volume of the test tone increases.
	At the Sound Pressure Meter:
	the value increases by approx. 4dB.
3.In the cockpit, on the overhead panel 50VU:	In the cabin, in all lavatories and at all attendant stations:
push to reset the OXYGEN TMR RESET pushbutton switch.	the volume of the test tone decreases to the normal level.
	At the Sound Pressure Meter:
	the value decreases by approx. 4dB.
4.In the cockpit, on the C/B panel 49VU:	In the cabin, in all lavatories and at all attendant stations:
open the C/B 2KS2 ENGINE/2/FADEC A/EIU2.	the volume of the test tone increases.
	At the Sound Pressure Meter:
	the value increases by approx. 6dB.
	In the cabin, in all lavatories and at all attendant stations:
close the C/B 2KS2.	the volume of the test tone decreases to the normal level.
	At the Sound Pressure Meter:
	the value decreases by approx. 6dB.
5.On the Test Tone Generator:	In the cabin, all lavatories and at all attendant stations:
set the White Noise test tone to 'off'.	the test tone stops.

Subtask 23-73-00-720-052-B ** ON A/C NOT FOR ALL

C. Measurement of the automatic gain increase

Sound Pressure Measurement ** ON A/C NOT FOR ALL

(1) Put the microphone of the SOUND PRESSURE METER - 90 TO 130DB (ACCURACY 1DB) below the first PAX loudspeaker.

NOTE: The cockpit door must stay closed during the test.

ACTION	RESULT
1.On the Aircraft Acoustic Tester: Set the switch (2) to the SPK position. Set the power switch (1) to the ON position.	The light in the power switch (1) comes on. The display (3) shows SPEAKER OFF.
	In the cabin, in all lavatories and at all attendant stations:
Push the center button below the display (3) until its top row shows SPK: NOISE. Push the right button below the display (3) until its bottom row shows VOL: 104 dPSPL.	You hear the test tone from all loudspeakers.
	At the Sound Pressure Meter:
2.Check the sound pressure level at the PAX loudspeaker.	The sound pressure level must not be less than the value given in the table for the sound pressure levels. Sound Pressure Measurement ON A/C NOT FOR ALL Sound Pressure Measurement ON A/C NOT FOR ALL
3.Make sure that all emergency oxygen-container door-stops are in the test position.
4.In the cockpit, on the overhead panel 21VU:	In the cabin, in all lavatories and at all attendant stations:
Lift the switch guard, push and release the MASK MAN ON pushbutton switch.	The doors of the emergency oxygen containers open to the test position.
	The volume of the test tone increases.
	At the Sound Pressure Meter:
	the value increases by approx. 4dB.
5.In the cockpit, on the overhead panel 50VU:	In the cabin, in all lavatories and at all attendant stations:
Push to reset the OXYGEN TMR RESET pushbutton switch.	The volume of the test tone decreases to the normal level.
	At the Sound Pressure Meter:
	The value decreases by approx. 4dB.
6.In the cockpit, on the C/B panel 49VU:	In the cabin, in all lavatories and at all attendant stations:
Open the C/B 2KS2 and 4KS2 (ENGINE/2/FADEC A/EIU2 and ENGINE/2/FADEC B/EIU2)	The volume of the test tone increases.
	At the Sound Pressure Meter:
	The value increases by approx. 6dB.
	In the cabin, in all lavatories and at all attendant stations:
Close the C/B 2KS2 and 4KS2. (ENGINE/2/FADEC A/EIU2 and ENGINE/2/FADEC B/EIU2)	The volume of the test tone decreases to the normal level.
	At the Sound Pressure Meter:
	The value decreases by approx. 6dB.
7.On the Aircraft Acoustic Tester:	In the cabin, all lavatories and at all attendant stations:
Set the power switch (1) to the OFF position.	The test tone stops.

5. Close-up
Subtask 23-73-00-860-139-B ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Put the cockpit handset back to the cradle.
(2) On the PTP, set the PA-level to the initial values.
(Ref. AMM TASK 23-73-00-860-004)
(3) On the emergency containers, turn the doorstops to the normal position and let them retract into their containers.

NOTE: Spring tension retracts the doorstops automatically when they are in the normal position.

(4) Make sure that the switch guard is in position on the MASK MAN ON pushbutton switch.
(5) Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
3JH1, 2JH1, 3JH2, 2JH2.
(6) Make sure that the work area is clean and clear of tools and other items.
(7) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002)

Subtask 23-73-00-860-139-C ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Put the cockpit handset back to the cradle.
(2) On the Flight Attendant Panel (FAP) 120RH, set the announcement volume levels in all cabin zones to the initial values.
(Ref. AMM TASK 23-73-00-860-009)
(3) On the emergency containers, turn the doorstops to the normal position and let them retract into their containers.

NOTE: Spring tension retracts the doorstops automatically when they are in the normal position.

[Rev.10 from 2021] 2026.04.02 06:12:28 UTC