DOC AIRBUS | AMM A320FWING ICE PROTECTION - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The wing ice protection system prevents ice on the leading edge of the slats 3, 4 and 5. The system, which is the same in the LH and the RH wing, uses hot air from the pneumatic system (Ref. AMM D/O 36-00-00-00). It is available in all flight conditions.
The two engines usually supply the pneumatic system with bleed air. If there is a failure, the cross-bleed valve opens and one engine can supply the two wings.
The system is only used during flight, but can be tested on the ground. To prevent heat damage to the slats, the ground test stops automatically after 30 seconds.
** ON A/C NOT FOR ALL The wing ice protection system prevents ice on the leading edge of the slats 3, 4 and 5. The system, which is the same in the LH and the RH wing, uses hot air from the pneumatic system (Ref. AMM D/O 36-00-00-00). It is available in all flight conditions.
The two engines usually supply the pneumatic system with bleed air. If there is a failure, the cross-bleed valve opens and one engine can supply the two wings.
The system is only used during flight, but can be tested on the ground. To prevent heat damage to the slats, the ground test stops automatically after 30 seconds.
2. Component Location
** ON A/C NOT FOR ALL | FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C ALL | |||||
| 3DL | P/BSW-ANTI ICE/WING | 25VU | 210 | 30-11-00 | |
| ** ON A/C NOT FOR ALL | |||||
| 9DL | VALVE-WING ANTI ICE CONTROL, L | 522AB | 522 | 30-11-51 | |
| ** ON A/C NOT FOR ALL | |||||
| 9DL | VALVE-WING ANTI ICE CONTROL, L | 522 | 30-11-51 | ||
| ** ON A/C NOT FOR ALL | |||||
| 10DL | VALVE-WING ANTI ICE CONTROL, R | 622AB | 622 | 30-11-51 | |
| ** ON A/C NOT FOR ALL | |||||
| 10DL | VALVE-WING ANTI ICE CONTROL, R | 622 | 30-11-51 | ||
A. Pneumatic Circuit
The wing ice protection system is supplied with hot air from the pneumatic system, downstream of the pre-cooler. The anti-ice control valve (in the wing, outboard of the engine pylon) isolates these two systems. A restrictor downstream of the anti-ice control valve controls the air flow.
The hot air goes through a lagged duct that connects the anti-ice control valve to the telescopic duct, inboard of RIB 13. The telescopic duct only attaches to the piccolo ducts in the slat 3. The piccolo ducts 3, 4 and 5 (that connect together with flexible ducts) release the hot air to heat the slats.
The wing ice protection system is supplied with hot air from the pneumatic system, downstream of the pre-cooler. The anti-ice control valve (in the wing, outboard of the engine pylon) isolates these two systems. A restrictor downstream of the anti-ice control valve controls the air flow.
The hot air goes through a lagged duct that connects the anti-ice control valve to the telescopic duct, inboard of RIB 13. The telescopic duct only attaches to the piccolo ducts in the slat 3. The piccolo ducts 3, 4 and 5 (that connect together with flexible ducts) release the hot air to heat the slats.
B. Air Distribution in the Slats
The piccolo ducts release the air into the slats through holes along their forward length. The air flows around the forward area of the slat then goes through acceleration slots into the rear section. It is then released overboard through the holes in the bottom surface of the slat.
The piccolo ducts release the air into the slats through holes along their forward length. The air flows around the forward area of the slat then goes through acceleration slots into the rear section. It is then released overboard through the holes in the bottom surface of the slat.
** ON A/C NOT FOR ALL
5. Interfaces
These components interface with, or are in, the wing ice protection system:
** ON A/C NOT FOR ALL These components interface with, or are in, the wing ice protection system:
- the anti-ice valve control-switch (3DL)
- the System Data Acquisition Concentrator/Electronic Centralized Aircraft Monitoring (SDAC/ECAM)
- the Environmental Control System Zone Control and Bleed Status Computer (ECS computer)
- the Centralized Fault Display System (CFDS)
- the landing-gear oleo proximity-switches.
6. Component Description
Wing Anti-Ice Control Valve (38E93-X) - Component Location ** ON A/C NOT FOR ALL
Wing Anti-Ice Control Valve (38E93-X) - Component Location ** ON A/C NOT FOR ALL
Wing Anti-Ice Control Valve (SAS 911-002A) - Component Location ** ON A/C NOT FOR ALL
Wing Anti-Ice Control Valve (SAS 911-002A) - Component Location ** ON A/C NOT FOR ALL
Wing Anti-Ice Control Valve (38E93-X) - Component Location ** ON A/C NOT FOR ALL Wing Anti-Ice Control Valve (38E93-X) - Component Location ** ON A/C NOT FOR ALL Wing Anti-Ice Control Valve (SAS 911-002A) - Component Location ** ON A/C NOT FOR ALL Wing Anti-Ice Control Valve (SAS 911-002A) - Component Location ** ON A/C NOT FOR ALL A. Wing Anti-Ice Control Valve FIN: 9-DL FIN: 10-DL
(1) General
Two wing anti-ice control-valves are installed on the aircraft, one in each wing leading-edge outboard of the engine pylons. A single ON/OFF switch on the cockpit overhead panel (25VU) operates the two valves.
The wing anti-ice control-valve:
The valves are selected electrically and operated pneumatically. If an electrical failure occurs, the valves will automatically go back to the closed position. The valves can be locked in the closed position to let the aircraft operate in non-icing conditions.
Two wing anti-ice control-valves are installed on the aircraft, one in each wing leading-edge outboard of the engine pylons. A single ON/OFF switch on the cockpit overhead panel (25VU) operates the two valves.
The wing anti-ice control-valve:
- isolates the anti-ice ducts from the pneumatic system bleed-air supply when anti-icing is not necessary
- controls the pressure of the wing anti-ice bleed-air, supplied by the pneumatic system.
The valves are selected electrically and operated pneumatically. If an electrical failure occurs, the valves will automatically go back to the closed position. The valves can be locked in the closed position to let the aircraft operate in non-icing conditions.
NOTE: The RH anti-ice control valve can be locked in the OPEN position, but the correct ECAM procedure must be applied (REF. 30-11-00-04).
When the valve(s) is/are locked in the CLOSED position, the aircraft is not permitted to fly into icing conditions.
A microswitch in the anti-ice valve senses when the valve is closed and gives a CLOSED/NOT CLOSED signal to the Environmental Control System Zone Control and Bleed Status Computer (ECS computer) and the Electronic Centralized Aircraft Monitoring (ECAM) system.
A visual/mechanical valve position indication is also given.
When the valve(s) is/are locked in the CLOSED position, the aircraft is not permitted to fly into icing conditions.
A microswitch in the anti-ice valve senses when the valve is closed and gives a CLOSED/NOT CLOSED signal to the Environmental Control System Zone Control and Bleed Status Computer (ECS computer) and the Electronic Centralized Aircraft Monitoring (ECAM) system.
A visual/mechanical valve position indication is also given.
(2) Operation
(a) For wing anti-ice control valve 38E93-X:
The wing anti-ice control valve has these primary components:
When bleed-air pressure is applied upstream of the butterfly valve, and the solenoid valve is energized, the actuator middle chamber pressurizes. This opens the butterfly valve and lets bleed-air pass through the anti-ice control valve.
The anti-ice valve controls its outlet pressure to 1.55 bar (22.4808 psi) plus or minus 0.17 bar (2.4656 psi). When the bleed-air pressure is more than this, the pressure in the pilot-valve inner chamber opens the needle valve. This releases the pressure in the actuator middle chamber and closes the butterfly valve.
When the outlet pressure goes below the controlled value the pilot-valve closes. The actuator middle chamber then pressurizes again and opens the butterfly valve. The constant movement of the butterfly valve keeps the valve outlet pressure at the specified value.
The two pressure switches monitor the pressure downstream of the butterfly valve to sense a valve malfunction. If the pressure increases to 2.1 bar (30.4579 psi) the related switch gives a 'high pressure' signal. If the pressure decreases to 1.0 bar (14.5038 psi) the related switch gives a 'low pressure' signal.
Two manual devices are supplied to lock the valve in the open or closed position. The lock screw can be used to attach the valve position indicator to the body. The lock plate can be used to safety the actuator rod in the extended or retracted position. Each device has an indicator to show that the valve is in the open or closed position.
The anti-ice valve has upstream and downstream ground-test connections. These let a functional test of the valve be done without bleed-air pressure in the ducts.
The wing anti-ice control valve has these primary components:
- an actuator assembly
- a butterfly valve
- a solenoid valve
- a pilot-valve assembly
- two pressure switches
- a valve position microswitch.
When bleed-air pressure is applied upstream of the butterfly valve, and the solenoid valve is energized, the actuator middle chamber pressurizes. This opens the butterfly valve and lets bleed-air pass through the anti-ice control valve.
The anti-ice valve controls its outlet pressure to 1.55 bar (22.4808 psi) plus or minus 0.17 bar (2.4656 psi). When the bleed-air pressure is more than this, the pressure in the pilot-valve inner chamber opens the needle valve. This releases the pressure in the actuator middle chamber and closes the butterfly valve.
When the outlet pressure goes below the controlled value the pilot-valve closes. The actuator middle chamber then pressurizes again and opens the butterfly valve. The constant movement of the butterfly valve keeps the valve outlet pressure at the specified value.
The two pressure switches monitor the pressure downstream of the butterfly valve to sense a valve malfunction. If the pressure increases to 2.1 bar (30.4579 psi) the related switch gives a 'high pressure' signal. If the pressure decreases to 1.0 bar (14.5038 psi) the related switch gives a 'low pressure' signal.
Two manual devices are supplied to lock the valve in the open or closed position. The lock screw can be used to attach the valve position indicator to the body. The lock plate can be used to safety the actuator rod in the extended or retracted position. Each device has an indicator to show that the valve is in the open or closed position.
The anti-ice valve has upstream and downstream ground-test connections. These let a functional test of the valve be done without bleed-air pressure in the ducts.
(b) For wing anti-ice control valve SAS 911-002A:
The wing anti-ice control valve has these primary components:
When bleed-air pressure is applied upstream of the butterfly valve, and the solenoid valve is energized, the actuator and damper chambers pressurize. This opens the butterfly valve and lets bleed-air pass through the anti-ice control valve.
The anti-ice valve controls its outlet pressure to 1.55 bar (22.4808 psi) +/- 0.17 bar (2.4656 psi). When the bleed-air pressure is more than this, the controller-housing sensor diaphragm opens the sensor valve. This releases the pressure in the actuator chamber to atmosphere and closes the butterfly valve.
When the outlet pressure goes below the controlled value, the damper spring closes the sensor valve. The actuator chamber then pressurizes again and opens the butterfly valve. The constant movement of the butterfly valve keeps the valve outlet pressure at the specified value.
The two pressure switches monitor the pressure downstream of the butterfly valve to sense a valve malfunction. If the pressure increases to 2.2 bar (31.9083 psi) the related switch gives a 'high pressure' signal. If the pressure decreases to 0.9 bar (13.0534 psi) the related switch gives a 'low pressure' signal.
The valve can be manually locked in the open or closed position by the lock pin. The pin is removed from the valve body and used to safety the valve indicator lever. When the lock pin is removed from its storage position, the actuator chamber is open to atmosphere, to prevent pneumatic operation of the valve.
The anti-ice valve has upstream and downstream ground-test connections. These let a functional test of the valve be done without bleed-air pressure in the ducts.
The wing anti-ice control valve has these primary components:
- an actuator body assembly
- a butterfly valve
- a controller-housing assembly
- a damper assembly
- a solenoid valve assembly
- two pressure switches
- a valve position microswitch.
When bleed-air pressure is applied upstream of the butterfly valve, and the solenoid valve is energized, the actuator and damper chambers pressurize. This opens the butterfly valve and lets bleed-air pass through the anti-ice control valve.
The anti-ice valve controls its outlet pressure to 1.55 bar (22.4808 psi) +/- 0.17 bar (2.4656 psi). When the bleed-air pressure is more than this, the controller-housing sensor diaphragm opens the sensor valve. This releases the pressure in the actuator chamber to atmosphere and closes the butterfly valve.
When the outlet pressure goes below the controlled value, the damper spring closes the sensor valve. The actuator chamber then pressurizes again and opens the butterfly valve. The constant movement of the butterfly valve keeps the valve outlet pressure at the specified value.
The two pressure switches monitor the pressure downstream of the butterfly valve to sense a valve malfunction. If the pressure increases to 2.2 bar (31.9083 psi) the related switch gives a 'high pressure' signal. If the pressure decreases to 0.9 bar (13.0534 psi) the related switch gives a 'low pressure' signal.
The valve can be manually locked in the open or closed position by the lock pin. The pin is removed from the valve body and used to safety the valve indicator lever. When the lock pin is removed from its storage position, the actuator chamber is open to atmosphere, to prevent pneumatic operation of the valve.
The anti-ice valve has upstream and downstream ground-test connections. These let a functional test of the valve be done without bleed-air pressure in the ducts.
B. Flow Restrictor
The flow restrictor is in the anti-ice duct, downstream of the anti-ice control valve. The internal diameter of the flow restrictor is smaller than that of the duct. Thus, it controls the airflow to the wings.
The flow restrictor is in the anti-ice duct, downstream of the anti-ice control valve. The internal diameter of the flow restrictor is smaller than that of the duct. Thus, it controls the airflow to the wings.
C. Telescopic Duct
The telescopic duct is at track 7. It connects the lagged anti-ice duct (on the front spar) to the piccolo duct in slat 3.
The telescopic duct has three sliding tubes with (ball type) couplings at each end. The sliding tubes decrease (in internal diameter) from 73.66 mm (2.9 in.) at the fixed leading-edge duct to 57.15 mm (2.25 in.) at the slat.
The telescopic duct is at track 7. It connects the lagged anti-ice duct (on the front spar) to the piccolo duct in slat 3.
The telescopic duct has three sliding tubes with (ball type) couplings at each end. The sliding tubes decrease (in internal diameter) from 73.66 mm (2.9 in.) at the fixed leading-edge duct to 57.15 mm (2.25 in.) at the slat.
D. Piccolo Ducts
Three piccolo ducts are in each wing, one in each of the slats 3, 4 and 5. Each piccolo duct has three rows of holes that face the leading-edge skin of the slat. The holes release the hot air on to the inner surface of the slat leading-edge skin.
The piccolo duct in the slat 3 has a diameter of 63.5 mm (2.50 in.) and decreases in size to 44 mm (1.73 in.) at the outboard end of the slat 5.
Three piccolo ducts are in each wing, one in each of the slats 3, 4 and 5. Each piccolo duct has three rows of holes that face the leading-edge skin of the slat. The holes release the hot air on to the inner surface of the slat leading-edge skin.
The piccolo duct in the slat 3 has a diameter of 63.5 mm (2.50 in.) and decreases in size to 44 mm (1.73 in.) at the outboard end of the slat 5.
E. Flexible (interconnecting) Ducts
The flexible ducts connect the piccolo ducts in the slats 3, 4 and 5. The flexible ducts are made of a high-tensile support-wire with a glass-silicone fabric cover.
The flexible ducts connect the piccolo ducts in the slats 3, 4 and 5. The flexible ducts are made of a high-tensile support-wire with a glass-silicone fabric cover.
7. Operation/Control and Indicating
The wing ice protection system starts when the ANTI ICE pushbutton switch (P/BSW) is operated. The switch is on the overhead control panel 25VU, in the cockpit.
The pneumatic system usually takes its supply of air from the engine intermediate pressure (IP) bleed. If the engine operates at low RPM, or the bleed air temperature is too low, the supply changes to the engine high pressure (HP) bleed. The pneumatic system makes this change-over automatically and supplies air to the wing ice protection system at the correct temperature. The wing anti-ice control valve keeps the air at the correct pressure.
The wing ice protection system starts when the ANTI ICE pushbutton switch (P/BSW) is operated. The switch is on the overhead control panel 25VU, in the cockpit.
The pneumatic system usually takes its supply of air from the engine intermediate pressure (IP) bleed. If the engine operates at low RPM, or the bleed air temperature is too low, the supply changes to the engine high pressure (HP) bleed. The pneumatic system makes this change-over automatically and supplies air to the wing ice protection system at the correct temperature. The wing anti-ice control valve keeps the air at the correct pressure.
A. Operation Logic
If one of the engines does not supply bleed air (because of a failure), the cross-bleed valve opens to let air go to the LH and the RH wing. In this configuration, the airflow in the system decreases.
If a failure of the wing anti-ice control valve(s) occurs on the ground, it is possible to manually lock it/them in the OPEN or CLOSED position.
If one of the engines does not supply bleed air (because of a failure), the cross-bleed valve opens to let air go to the LH and the RH wing. In this configuration, the airflow in the system decreases.
If a failure of the wing anti-ice control valve(s) occurs on the ground, it is possible to manually lock it/them in the OPEN or CLOSED position.
NOTE: The RH anti-ice control valve can be locked in the OPEN position, but the correct ECAM procedure must be applied (REF. 30-11-00-04).
When the valve(s) is/are locked in the CLOSED position, the aircraft is not permitted to fly into icing conditions.
The limits of the wing ice protection system are:
When the valve(s) is/are locked in the CLOSED position, the aircraft is not permitted to fly into icing conditions.
The limits of the wing ice protection system are:
| Supply Pressure 1.33 to 1.67 bar (20 to 25 psi) |
| Supply Temperature 185 to 215 deg. C. (365 to 419 deg. F) |
| Mass Flow Through Valve 0.327 kg/s (0.7 lb/s) |
| at 22,000 ft. |
B. Controls and Indications
The wing ice protection system is energized by the pushbutton switch (P/BSW) 3DL on the cockpit overhead panel 25VU. The P/BSW (3DL) has two illuminated conditions:
The procedure to operate the anti-ice system on the ground is the same as in flight. But on the ground the relay 4DL (ground test) supplies the ground to the relay 5DL. For safety, the relay 4DL also limits the system operation time to 30 seconds.
The FAULT light comes on (amber) if:
The electrical circuit gives the ECS computer and the SDAC/ECAM this data:
When the FAULT light of the P/BSW (3DL) comes on:
The wing ice protection system is energized by the pushbutton switch (P/BSW) 3DL on the cockpit overhead panel 25VU. The P/BSW (3DL) has two illuminated conditions:
- FAULT : amber
- ON : blue.
The procedure to operate the anti-ice system on the ground is the same as in flight. But on the ground the relay 4DL (ground test) supplies the ground to the relay 5DL. For safety, the relay 4DL also limits the system operation time to 30 seconds.
The FAULT light comes on (amber) if:
- the left valve air outlet pressure is low
- the right valve air outlet pressure is low
- the left and/or the right valve fails to close
- the left and/or the right valve fails to open
- the control relay (5DL) does not operate
- the change-over relay (6DL) does not operate
- the fault relay (7DL) does not operate
- there is an electrical power failure to the wing ice protection system.
The electrical circuit gives the ECS computer and the SDAC/ECAM this data:
- the system selected (SDAC/ECAM only)
- the system ON
- the left and/or the right valve closed
- the left and/or the right air outlet pressure low
- the left and/or the right air outlet pressure high.
When the FAULT light of the P/BSW (3DL) comes on:
- the ECAM system automatically starts
- there is a single chime
- the master caution light comes on
- the ECAM (lower DU) shows warning messages.
C. System Faults and Warnings
There is a 15 second delay before the warning messages show on the ECAM system. This prevents warnings that are not necessary because of low pressure when the system is set to ON.
When the system is set to ON, the FAULT light comes on until the pressure is above the low limit.
There is a 15 second delay before the warning messages show on the ECAM system. This prevents warnings that are not necessary because of low pressure when the system is set to ON.
When the system is set to ON, the FAULT light comes on until the pressure is above the low limit.
(1) System set to OFF and the control valve is not closed (aircraft on the ground)
After the aircraft has landed and if the control valve does not close within 35 seconds, the system gives:
After the aircraft has landed and if the control valve does not close within 35 seconds, the system gives:
- an amber warning
- a single chime
- a warning on the ECAM to tell the flight crew to turn off the system to prevent overheat damage (Ref. AMM D/O 31-51-00-00).
(2) System set to OFF and the control valve is not closed (in flight)
If the control valve does not close (with the system set to OFF) in flight, the system gives:
The warning is inhibited during take-off (from a ground speed of 80kts to an altitude of 1,500ft) and landing (from an altitude of 800ft to a ground speed of 80kts).
If the control valve does not close (with the system set to OFF) in flight, the system gives:
- an amber warning
- a single chime
- an ECAM warning (Ref. AMM D/O 31-51-00-00).
The warning is inhibited during take-off (from a ground speed of 80kts to an altitude of 1,500ft) and landing (from an altitude of 800ft to a ground speed of 80kts).
(3) System set to the ON position and the control valve is closed.
If one of the two or the two control valve(s) does/do not open (when the system is set to ON) within 15 seconds, the system gives:
The FAULT (amber) light on the P/BSW (3DL) will come on.
If one of the two or the two control valve(s) does/do not open (when the system is set to ON) within 15 seconds, the system gives:
- an amber warning
- a single chime
- data shown on the ECAM related to the position of the engine bleed valve(s) and the cross-bleed valve (Ref. AMM D/O 31-51-00-00).
The FAULT (amber) light on the P/BSW (3DL) will come on.
(4) System set to the ON position and the pressure is not in limits.
When the system is set to the ON position and the pressure is too high (for a period in excess of 40 seconds), the system gives:
The FAULT (amber) light on the P/BSW will not come on.
When the system is set to the ON position and the pressure is too low (for a period in excess of 15 seconds), the system gives:
The FAULT (amber) light on the P/BSW (3DL) will come on.
When the system is set to the ON position and the pressure is too high (for a period in excess of 40 seconds), the system gives:
- the applicable ECAM warning(s).
The FAULT (amber) light on the P/BSW will not come on.
When the system is set to the ON position and the pressure is too low (for a period in excess of 15 seconds), the system gives:
- an amber warning
- a single chime
- the applicable ECAM warning(s) related to the position of the engine bleed valve and the cross-bleed valve (Ref. AMM D/O 31-51-00-00).
The FAULT (amber) light on the P/BSW (3DL) will come on.
A. Automatic Test and Test Monitoring
When the aircraft is on the ground, the automatic test facility starts when:
The SDAC/ECAM monitors the test function. If the test continues for 35 seconds or more, the ECAM gives a SHUT DOWN PNEUMATIC SYSTEM warning message. This prevents overheat damage to the slats.
At the start of the test sequence, the amber warning light comes on. The light stays on until the pressure in the system goes above the low-pressure limit.
If the change-over relay (6DL) does not operate, the amber warning light stays on during the test sequence. The light only goes off at the end of the test time, or when the pushbutton switch (3DL) is set to the OFF position.
If the fault relay (7DL) does not operate, the amber warning light comes on when the aircraft 5V warning-light system has power.
If the electrical control system to the wing ice protection system has a power failure, the amber warning light comes on when the aircraft 5V warning-light system has power.
The TEMP CTL of the air-conditioning class 3 faults gives access to the ice protection system on the CFDS (Ref. TSM Chapter 21).
When the aircraft is on the ground, the automatic test facility is started when the control switch (3DL) is selected ON and is stopped after 30 seconds by the time delay relay. SDAC/ECAM monitors the test function and if the test continues for 35 seconds or more, the ECAM signals a SHUT DOWN PENUMATIC SYSTEM warning message (to prevent overheat damage to the slats).
At the start of the test sequence, the amber warning light on the glareshield will be illuminated until the pressure in the system has risen above the low pressure setting.
If the change-over relay (6DL) fails to operate, the amber warning light will remain ON throughout the test sequence. The light will only extinguish at the end of the test time, or when the control switch (3DL) is selected off.
If the fault relay (7DL) fails to operate, the amber warning light will be illuminated when power is on the aircraft 5V warning-light power-system.
If there is a power failure to the electrical control system, the amber fault light will be illuminated when power is available to the aircraft 5V warning-light system.
Access to the wing anti-ice system on the CFDS is through the TEMP CTL of the air-conditioning class 3 faults (Ref. TSM Chapter 21).
When the aircraft is on the ground, the automatic test facility starts when:
- the pushbutton switch (3DL) is set to the ON position
- the time delay relay stops the test after 30 seconds.
The SDAC/ECAM monitors the test function. If the test continues for 35 seconds or more, the ECAM gives a SHUT DOWN PNEUMATIC SYSTEM warning message. This prevents overheat damage to the slats.
At the start of the test sequence, the amber warning light comes on. The light stays on until the pressure in the system goes above the low-pressure limit.
If the change-over relay (6DL) does not operate, the amber warning light stays on during the test sequence. The light only goes off at the end of the test time, or when the pushbutton switch (3DL) is set to the OFF position.
If the fault relay (7DL) does not operate, the amber warning light comes on when the aircraft 5V warning-light system has power.
If the electrical control system to the wing ice protection system has a power failure, the amber warning light comes on when the aircraft 5V warning-light system has power.
The TEMP CTL of the air-conditioning class 3 faults gives access to the ice protection system on the CFDS (Ref. TSM Chapter 21).
When the aircraft is on the ground, the automatic test facility is started when the control switch (3DL) is selected ON and is stopped after 30 seconds by the time delay relay. SDAC/ECAM monitors the test function and if the test continues for 35 seconds or more, the ECAM signals a SHUT DOWN PENUMATIC SYSTEM warning message (to prevent overheat damage to the slats).
At the start of the test sequence, the amber warning light on the glareshield will be illuminated until the pressure in the system has risen above the low pressure setting.
If the change-over relay (6DL) fails to operate, the amber warning light will remain ON throughout the test sequence. The light will only extinguish at the end of the test time, or when the control switch (3DL) is selected off.
If the fault relay (7DL) fails to operate, the amber warning light will be illuminated when power is on the aircraft 5V warning-light power-system.
If there is a power failure to the electrical control system, the amber fault light will be illuminated when power is available to the aircraft 5V warning-light system.
Access to the wing anti-ice system on the CFDS is through the TEMP CTL of the air-conditioning class 3 faults (Ref. TSM Chapter 21).