DOC AIRBUS | AMM A320FSPOILER HYDRAULIC ACTUATION - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The hydraulic actuation is achieved by one electrohydraulic servocontrol with asymmetrical chambers, for each spoiler.
** ON A/C NOT FOR ALL The hydraulic actuation is achieved by one electrohydraulic servocontrol with asymmetrical chambers, for each spoiler.
2. Component Location
Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL
Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL
Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL | FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 31CE1 | SERVO CTL-SPLR1, L G | 573BB | 574 | 27-64-51 | |
| 31CE2 | SERVO CTL-SPLR1, R G | 673BB | 674 | 27-64-51 | |
| 31CE3 | SERVO CTL-SPLR2, L Y | 575BB | 582 | 27-64-51 | |
| 31CE4 | SERVO CTL-SPLR2, R Y | 675BB | 682 | 27-64-51 | |
| 31CE5 | SERVO CTL-SPLR3, L B | 575DB | 583 | 27-64-51 | |
| 31CE6 | SERVO CTL-SPLR3, R B | 675DB | 683 | 27-64-51 | |
| ** ON A/C ALL | |||||
| 31CE7 | SERVO CTL-SPLR4, L Y | 584 | 27-64-51 | ||
| 31CE8 | SERVO CTL-SPLR4, R Y | 684 | 27-64-51 | ||
| 31CE9 | SERVO CTL-SPLR5, L G | 585 | 27-64-51 | ||
| 31CE10 | SERVO CTL-SPLR5, R G | 685 | 27-64-51 | ||
| ** ON A/C NOT FOR ALL | |||||
| 31CE1 | SERVO CTL-SPLR1, L G | 574 | 27-64-51 | ||
| 31CE2 | SERVO CTL-SPLR1, R G | 674 | 27-64-51 | ||
| 31CE3 | SERVO CTL-SPLR2, L Y | 582 | 27-64-51 | ||
| 31CE4 | SERVO CTL-SPLR2, R Y | 682 | 27-64-51 | ||
| 31CE5 | SERVO CTL-SPLR3, L B | 583 | 27-64-51 | ||
| 31CE6 | SERVO CTL-SPLR3, R B | 683 | 27-64-51 | ||
3. Component Description
A. Servocontrols of Spoilers 1 thru 5 FIN: 31-CE-1 FIN: 31-CE-2 FIN: 31-CE-3 FIN: 31-CE-4 FIN: 31-CE-5 FIN: 31-CE-6
Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL
Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL
Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL
Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL Location of Spoiler Servocontrol ** ON A/C NOT FOR ALL (1) General
The five fixed body servocontrols (one per spoiler) are interchangeable.
The five fixed body servocontrols (one per spoiler) are interchangeable.
A. Normal operation with the servocontrol pressurized
In this case, the high pressure is applied to the bypass valve (3) and to the plunger (7) which hold the closing valve (6). Thus the two actuator chambers are connected to the servovalve control lines.
The feedback transducer (11) provides the servoloop feedback.
The servovalve has a biased zero. When the input signal is equivalent to the electrical zero, its spool valve is open at 25 % of its max. stroke and connects the supply line of the small chamber to the high pressure.
When the spoiler is at neutral, it is held against the servocontrol stop by nulling the current of the servovalve.
The servovalve then feeds the high pressure to the small chamber and applies the piston rod to its internal retraction stop.
In this case, the high pressure is applied to the bypass valve (3) and to the plunger (7) which hold the closing valve (6). Thus the two actuator chambers are connected to the servovalve control lines.
The feedback transducer (11) provides the servoloop feedback.
The servovalve has a biased zero. When the input signal is equivalent to the electrical zero, its spool valve is open at 25 % of its max. stroke and connects the supply line of the small chamber to the high pressure.
When the spoiler is at neutral, it is held against the servocontrol stop by nulling the current of the servovalve.
The servovalve then feeds the high pressure to the small chamber and applies the piston rod to its internal retraction stop.
B. Operation after an electrical failure
In this case the servovalve input signal is nulled. This biases the servovalve in order to make the piston rod retract.
In this case the servovalve input signal is nulled. This biases the servovalve in order to make the piston rod retract.
C. Operation after a hydraulic failure
When the pressure drops :
The calibration valve (4) and the anti-cavitation valve (5) prevent any low pressure in the small chamber by slowing, down, the transit of the fluid surplus of the large chamber in the return line.
When the pressure drops :
- the relief valve (2) moves under the action of its spring. This isolates the servovalve from the high pressure
- the plunger (7) frees the closing valve (6). This prevents the extension of the piston rod
- the bypass valve (3) moves rearward under the action of its spring.
This isolates the piston chambers from the servovalve control lines then the two piston chambers are interconnected in the retraction direction via the closing valve (6).
The calibration valve (4) and the anti-cavitation valve (5) prevent any low pressure in the small chamber by slowing, down, the transit of the fluid surplus of the large chamber in the return line.
D. Operation in case of high pressure decrease
When the HP decreases but remains sufficient to keep the bypass valve in the active mode, the piston retracts under external forces. These forces are higher than those delivered by the large chamber pressure. They cause the servovalve spool valve to open in the direction which connects the large chamber to the pressure line.
Then the check valve (2) allows to servovalve retraction at low speed as the fluid transits through the servovalve leakages.
When the HP decreases but remains sufficient to keep the bypass valve in the active mode, the piston retracts under external forces. These forces are higher than those delivered by the large chamber pressure. They cause the servovalve spool valve to open in the direction which connects the large chamber to the pressure line.
Then the check valve (2) allows to servovalve retraction at low speed as the fluid transits through the servovalve leakages.
E. Operation on the ground with the servocontrol depressurized
- In the event of a thermal overpressure in the small chamber, the pressure increasing valve (8) pushes the plunger (7) which causes the valve (6) to open, and thus the small chamber is unlocked.
- In order to enable ground maintenance operations, the small chamber can also be unlocked manually by means of the maintenance unlocking crank-lever (10).
This lever also holds the maintenance pressure-inhibiting valve (9), thus the control chamber of the bypass valve is connected to the return line.
This action avoids spoiler movement even if the servocontrol is then pressurized.
F. Maintenance and rigging facilities
The maintenance is "on position".
The items below are line Replaceable Units (LRUs) :
The maintenance is "on position".
The items below are line Replaceable Units (LRUs) :
- filter
- servovalve.