A320 Systems Flashcards
1
Q
ATA 21
At what cabin altitude is ECAM EXCESS CAB ALT triggered
A
9,550 ft
2
Q
ATA 21
Automatic pressurization law
A
• CPC uses:
- Landing elevation and QNH from FMGC
- Pressure altitude from ADIRS
• Pressurization schedule:
- Ground (before takeoff and 55 s after landing)
Outflow valve opens fully to ensure that there is no residual cabin pressure
- Take Off, CPC pressurizes at ΔP 0.1 PSI to avoid a pressure surge at rotation.
- Climb, Cabin altitude varies according to a fixed pre-programmed law that takes into account the aircraft’s actual rate of climb.
- Cruise, Cabin altitude is kept at level off value, or at landing field elevation, whichever is higher.
- Descent:
. Cabin rate of descent computed in order to get cabin pressure equal to landing field pressure +0.1 PSI shortly before landing
. Maximum descent rate is 750 ft/min
3
Q
ATA 21
Cabin Pressure Controllers
A
- 2 identical, independent, digital controllers automatically control the system, by maintaining proper cabin pressure
- They receive signals from:
- ADIRS
- FMGC
- EIU
- LGCIU
- When the system is in automatic or semi-automatic mode, 1 controller is active, the other is on standby
- The controllers communicate with each other via a cross-channel link
4
Q
ATA 21
Components of the Pressurization system
A
- 2 Cabin Pressure Controllers (CPC)
- 1 Residual Pressure Control Unit (RPCU)
- 1 Outflow valve, with an actuator that incorporates 3 motors (2 for automatic and 1 for manual operation)
- 1 Control panel
- 2 Safety valves
5
Q
ATA 21
Components of the Avionics ventilation system
A
- 1 Avionics Equipment Ventilation Controller (AEVC)
- 2 electric fans
- Skin air inlet and extract valve
- Air conditioning inlet valve
- Skin exchange isolation valve
6
Q
ATA 21
Conditions for an automatic transfer of CPC
A
An automatic transfer occurs:
- 70 s after each landing
- If the operating system fails
7
Q
ATA 21
Describe the Packs operation
A
- 2 packs operate automatically and independently of each other
- Warm pre-conditioned bleed air enters via the pack flow control valve, and goes through:
- The primary heat exchanger
- The compressor section of the air-cycle machine where air is Compressed to a higher pressure and temperature
- The main heat exchanger where air is cooled again
- A water separator system where air is dried
- The turbine section, where air expands and generates power to drive the compressor and the cooling air fan.
The removal of energy during this process reduces air temperature, resulting in very low air temperature at turbine discharge.
8
Q
ATA 21
ECAM BLEED Page, Packs indications
A
From top to bottom: • Outlet temp • Bypass Valve position • Compressor Outlet temp • Flow
9
Q
ATA 21
Amber HOT AIR Fault light
A
• Fault light comes ON when:
- Duct reaches 88 °C
- HOT AIR pressure regulating valve disagrees with selected position
- Hot air pressure regulating valve and trim air valves close automatically
- When temperature drops below 70 °C and Hot Air is switched OFF, light goes OFF
10
Q
ATA 21
Amber Pack Fault light
A
- Pack flow control valve disagrees with selected position
- Compressor outlet overheat
- Pack outlet overheat
11
Q
ATA 21
Pressurization operation
A
• Automatic Operation:
- FMGS sends an external pressurization Schedule to the CPC
- When FMGS data is not available, select manually the landing field elevation for the CPC to use an internal pressurization Schedule
• Manual Operation, Cabin altitude is controlled via the manual motor of the outflow valve by operating a switch on the pressurization control panel
12
Q
ATA 21
Pressurization Safety Valves
A
- 2 independent pneumatic safety valves prevent cabin pressure from going too high (8.6 PSI above ambient) or too low (1 PSI below ambient)
- They are located on the rear pressure bulkhead, above the flotation line
13
Q
ATA 21
RAM AIR inlet flap logic
A
- Takeoff, the ram air inlet flap closes when takeoff power is set and the main landing gear struts are compressed
- During landing, it closes as soon as the main landing gear struts are compressed, as longas speed is at or above 70 kt,It opens 20 s after the speed drops below 70 kt
14
Q
ATA 21
RAM AIR operation
A
- Used to ventilate the cockpit and cabin to remove smoke, or if both packs fail
- If ΔP is less than 1 PSI and ditching not selected, RAM AIR P/B ON:
- RAM AIR valve opens
- Outflow valve opens about 50 %, provided that it is under automatic control
15
Q
ATA 21
Residual cabin pressure
A
Red light flashes close to door window when:
Both engines are stopped and Slides are disarmed
16
Q
ATA 21
Residual Pressure Control Unit
A
Residual Pressure Control Unit (RPCU) automatically opens the outflow valve on ground in case of abnormal residual pressure when:
• Both CPCs are failed, or manual mode is selected and• The aircraft is on ground and
• All engines are shutdown or all ADIRS indicate an airspeed below 100 kt.
17
Q
ATA 21
Under which condition, Hot air pressure regulating valve close automatically
A
- Duct overheats
- 1 Cockpit trim air valve fails
- Both cabin trim air valves fail
18
Q
ATA 21
Under which condition, Pack Flow Control Valve close automatically
A
- Pack Overheating
- Engine Starting
- Operation of Fire or Ditching P/b
19
Q
ATA 21
Amber Ventilation Blower Fault light
A
- Blowing pressure low
- Duct overheat
- Computer power supply fails
- Smoke warning activated
20
Q
ATA 21
Amber Ventilation Extract Fault light
A
- Extract pressure low
- Computer power supply fails
- Smoke warning activated
21
Q
ATA 21
Ventilation operation
A
• On ground:
- Before application of TO power, ventilation system is in open circuit configuration (closed configuration when skin temperature is low)
- After application of TO power, ventilation system is in closed circuit configuration
• In Flight, ventilation system is in closed circuit configuration
22
Q
ATA 21
Ventilation, Blower/Extract on OVRD
A
• Either pushbutton on OVRD:
‐ System goes to closed circuit configuration
‐ Air conditioning air is added to ventilation air (blower fan stops if BLOWER P/B is OVRD)
• Both pushbuttons on OVRD:
‐ Air flows from air conditioning system and then overboard
‐ Extract fan continues to run
23
Q
ATA 21
Air Conditioning System Controler Fault
A
• 1 Lane fails: no effect
• 2 Lanes fail:
- Pack is lost
- Hot air pressure regulated and trim air valve close
24
Q
ATA 21
Air Conditioning System Controller / Pack Controller operation
A
• Each Air Conditioning System Controller / Pack Controller regulate the temperature by:
- Modulating the bypass valve and the ram air inlet flap of its associated pack for basic regulation
- Modulating Trim air valves in each zone duct for optimized regulation
25
ATA 21
| Air Conditioning, describe the system
• The A320 is separated into 3 different zones
• 2 Air Conditioning System Controller regulate the temperature of each zone by ordering air flow from:
- 1 Mixing unit, supplied by both packs and 2 recycling cabin fans for cold air
- 1 Hot air pressure regulating valve and 1 Trim air valves in each zone duct for hot air
26
ATA 22
| 1 engine fails during Climb above ACC ALT, what speed is managed by the FMGEC
* BELOW EO REC MAX, GD: Speed change is gradual to prevent a thrust reduction
* ABOVE EO REC MAX, EOLRC speed at EO REC MAX: Speed change is gradual to prevent a thrust reduction
27
ATA 22
| 1 engine inoperative, AP&FD bank angle limits during takeoff and approach phases
* Speed below maneuvering Speed (F,S,GD) -10 kt : 15°
* Speed above maneuvering speed -3 kt : 25°
* Linear increase from 15 to 25° with speed increasing from maneuvering - 10kt to -3kt
28
ATA 22
| Aircraft Gross Weight and CG, how is it computed
• Before engine start the FMGS computes GW and Cg
• After engine start:
- The FMGS computes GW and Cg displayed on ECAM SD - The FAC computes GW and Cg for ECAM warnings
29
ATA 22
| Conditions for engaging Go-Around Mode
Setting at least 1 thrust lever to TOGA detent engages SRS/GA TRK modes if:
‐ Flaps lever is at least in position 1
‐ Aircraft in flight or on ground for less than 30 s
30
ATA 22
| Flight Management functions of FMGS
* Navigation and management of navigation radios
* Management of flight planning
* Prediction and optimization of performance
* Display management
31
ATA 22
| Ground Speed mini
• Minimum GS is the Ground speed at touch down using: - VAPP speed
- Wind inserted in the PERF APPR page
• On approach, the FMGS continuously computes the speed target using actual windin order to keep GS at or above Ground Speed Mini
• Lowest speed target is limited to VAPP
• Highest speed target is limited to VFE next CONF or VFE-5 in CONF FULL
32
ATA 22
| How does Back-up navigation mode work
NAV B/UP links the MCDU to its associated IRS in order to provide basic flight planning functions in case of FM 1 +2 failure
33
ATA 22
| LAND mode
• Automatically engages below 400 ft RA when LOC and G/S modes are engaged
• Consequently, LOC and G/S are locked and no action on FCU will disengage the mode
• Disengagement conditions:
‐ Go-around mode engagement
‐ Both AP/FDs OFF
‐ Aircraft on ground for at least 10s with autopilot disconnectedand APPR PB pressed
34
ATA 22
| Nav Back-Up mode, how do you modify the Flight Plan
```
• FM NAV data base is lost
• Available revisions:
- WPT insertion/deletion
- OVERFLY insertion/deletion
- DIR TO- CLR
• Waypoint identification:
- 3 letters (PUD) if Waypoint in the MCDU active F-PLN
- Coordinates LAT/LONG or IDENT/LAT/LONG
```
35
ATA 22
| Permanent disconnect of A/THR
* Instinctive PB pressed for more than 15s
* A/THR system disconnects for the remainder of the flight and can only be recovered at the next FMGC power-up (on ground)
* All A/THR functions including ALPHA FLOOR are lost
36
ATA 22
| Situations when A floor is not available
* SFCC1 and FAC2 failed
* SFCC2 and FAC1 failed
* Both FCU channels failed
* 1 EIU failed
* Both FMGCs failed
* Alternate flight control law
* Direct flight control law
* FADECs in N1 degraded mode
* 1 engine-out with slats/flaps extended
37
ATA 22
| Speed measurement system, how does it work
• Speed is deduced from measurement of 2 pressures:
- Total pressure (Pt) by 3 Pitot probes fitted with drains and heating to remove water and prevent icing
- Static pressure (Ps) by 6 Static pressure sensors
• 8 ADMs (Air Data Module) convert pneumatic measures into electrical signals
• 3 ADRs use ADM signals to compute independent speeds:
- ADR 1 uses Captain ADM
- ADR 2 uses FO ADM
- ADR 3 uses Standby ADM
• ISIS elaborates speed directly from pneumatic inputs using same static and total pressure sensors as ADR3
38
ATA 22
| SRS mode, Go Around Speed target computed by FMGC
Max of VLS, VAPP, IAS at time of Go Around limited to:
- AEO, VAPP + 25
- OEI, V2 + 15
39
ATA 22
| SRS mode, Take Off Speed/Pitch target computed by FMGC
• Speed:
- AEO, V2+10
- OEI, IAS at time of failure (mini V2, maxi V2+15)
• Pitch AEO:
- Pitch to fly V2+10 limited to a maximum of 17.5°
- Pitch to achieve a minimum 0.5º climb gradient limited to 22.5°
40
ATA 22
| Windshear reactive warning availability
* Take-off, 3s after liftoff up to 1300 feet
* Landing, from 1300ft to 50ft RA
* CONF 1 at least selected
41
ATA 23
| Cabin Intercommunication Data System components
• 2 CIDS directors connected in parallel, 1 active and 1 standby
• Flight Attendant Panel (FAP) to monitor and control cabin systems
• Attendant Indication Panels (AIP), After Attendant Panels (AAP) and Area Call Panels (ACP)
• Decoder/Encoder Units (DEUs) linked to the 2 directors:
- Type A units for passengers installed along the cabin
- Type B units for attendants installed near the exit doors
42
ATA 23
| Cabin Intercommunication Data System functions
The Cabin Intercommunication Data System (CIDS) transmits, controls, and processes signals for the following cabin systems:
• Cabin and service interphone
• Passenger address
• Passenger lighted signs
• Reading lights
• General cabin illumination
• Emergency evacuation signalling
• Lavatory smoke detectors and indicators
• Passenger entertainment music and video
• Escape slide bottle pressure monitoring
• Vacuum system control function
• Cargo and lavatory smoke detection function
43
ATA 23
| CVR, when is it switched ON
```
CVR is energized:
• With GND CTL P/b ON
• On Ground:
- First 5' after powering the electrical network
- When 1 engine is running
• In Flight
```
44
ATA 24
| Battery only configuration, Electrical system supply
* BAT1, AC STAT INV and AC ESS BUS
| * BAT2, DC ESS BUS
45
ATA 24
| Circuit Breaker System
```
• Position:
- CM1 CB on Overhead panel
- CM2 CB behind the FO
• Colors:
- Green, Monitored
- Black, Not monitored
- Yellow, Used on EMER ELEC
- Red, Temporary deactivated systems: WTB
- White, Permanently deactivated systems
```
46
ATA 24
| Emergency Generator
* Driven by the RAT via the Blue HYD system
* MAN ON PB on EMER ELEC PWR panel controls RAT extension and EMER GEN connexion
* Power cuts off after landing when speed is less than 100kt
47
ATA 24
| IDG Fault light (Amber)
• Light ON and ECAM caution if:
- Oil overheats (above 185 °C)
- Low oil pressure (inhibited with N2 below 14 %)
• Fault light extinguishes when IDG is disconnected.
48
ATA 24
| IDG Label Amber on ECAM
* High Oil Outlet Temp
* Low Oil Pressure
* IDG disconnected
49
ATA 24
| MAINT BUS switch on Cabin Circuit Breaker Panel
Supply AC/DC GND/FLT BUS directly without supplying the entire aircraft
50
ATA 24
| Priority logic for powering AC 1 Bus on ground
```
Order from Top to Bottom:
• GEN 1
• EXT PWR
• APU GEN
• GEN 2
```
51
ATA 24
| Use of ESS TR
Back up power supply for DC ESS BUS from AC ESS BUS when TR1 or TR2 fails
52
ATA 24
| GEN 1 LINE pb-sw
* Used in case of Avionics smoke
* Disconnect GEN1 BUS from IDG1
* Inner TK Fuel Pumps powered directly by IDG1
53
ATA 24
| RAT manual extension, difference between using HYD/EMER ELEC Panel pb-sw
* HYD panel, RAT supplies only Blue hydraulic pressure
| * EMER ELEC panel, RAT supplies Blue hydraulic pressure and emergency electrical power
54
ATA 26
| Avionics Smoke detection system
• 1 smoke detector located in the air extraction duct of the avionics ventilation system
• When smoke is detected for more than 5 s:
‐ Single chime
‐ Master Caution
‐ ECAM AVNCS SMOKE
‐ EMER ELEC panel, Smoke light ON
‐ Ventilation panel, Blower and Extract Fault lights ON
55
ATA 26
| Cargo Fire extinguishing system
• 2 fire bottles supply 3 nozzles:
- 1 in FWD compartment
- 2 in AFT compartment
• Each bottle has 2 discharge heads, 1 for each compartment
• When the FWD (AFT) SMOKE light comes ON:
- Select AGENT 1 to discharge Bottle 1 (takes 60s)
- 60 min after, AGENT 2 DISCH light goes ON
- Select AGENT 2 to discharge Bottle 2 (takes 90 min)
• The 2 bottles ensure sufficient agent concentration for 205 min
56
ATA 26
| Cargo Smoke detection system component
Cargo smoke detection system consists of:
• Cavities in cargo ceiling panels, they hold 2 smoke detectors each (dual loop principle):
‐ Forward compartment, 1 cavity
‐ Aft compartment, 2 cavities
• The CIDS, receives signals from detectors and transmits to the ECAM
57
ATA 26
| Fire detection loops
```
The gas detection loops has:
• 3 sensing elements for each engine:
- 1 in the pylon nacelle
- 1 in the engine core
- 1 in the engine fan section
• 1 sensing element in the APU compartment
```
58
ATA 26
| Fire Detection system operation
* When a sensing element detects heat, it sends a signal to the fire detection unit
* If loops A&B detect heat, the fire warning is triggered
* If 1 loop is faulty (break or loss of electrical supply), the other loop protects the aircraft
* If the system detects an APU fire while the aircraft is on the ground, it shuts down the APU automatically and discharges extinguishing agent
59
ATA 26
| Fire Detection system, Engines and APU Components
• The fire detection system consists of:
‐ 1 Fire Detection Unit (FDU)
‐ 2 identical gas detection loops (A&B) mounted in parallel on each engine and on the APU
60
ATA 26
| Fire Loop Fault Caution conditions
* 1 loop is faulty
* Both loops are faulty
* Fire detection unit fails
61
ATA 26
| Fire Pushbutton actions
* Silence the aural fire warning
* Arm fire extinguisher squibs
* Close low-pressure fuel valve
* Close hydraulic shut off valve
* Close engine bleed valve
* Close pack flow control valve
* Cut off FADEC power supply
* Deactivate the IDG
62
ATA 26
| Fire warning conditions
* Fire signal from loop A&B
* Fire signal from 1 loop when the other is faulty
* Breaks in both loops occuring within 5 s of each other
* Test performed on the control panel
63
ATA 26
| Lavatory Smoke detection system
• Lavatory smoke detection system consists of:
- 1 smoke detector in each lavatory
- The CIDS
• When smoke is detected, the CIDS generates a warning in the cabin and sends a signal to the FWC for ECAM Warning Lavatory smoke
64
ATA 27
| Alpha Lock
• Slats Alpha Lock prevent high AOA, low speed slat retraction:
- Flap lever moved from 1 to 0", A. LOCK" pulses on E/WD Slat indication
- When AOA and speed are normal, Slats retract to 0
• If Alpha Lock function is triggered, accelerate to allow slats retraction.
65
ATA 27
| Automatic Retract system
• ARS is activated in Conf 1+F when IAS reaches 210 kts: - Flaps are automatically retracted to 0
- PFD VFE displayed change from 215 to 230 kts
- If IAS decreases below 210kt, flaps will not extend back to 1+F
66
ATA 27
| Conditions for partial Ground spoiler extension at Landing
• Ground spoilers partially extend when:
- Reverse is selected on at least 1 engine (other one at idle)
- 1 main landing gear strut is compressed
• This partial extension leads to full ground spoiler extension by:
- Decreasing the lift
- Easing the compression of second main landing gear strut
67
ATA 27
| Conditions that trigger the Wing Tip Brakes
* Uncommanded movement
* Assymetry
* Mechanism overspeed
* Symmetrical runaway
68
ATA 27
| Consequence of 1 hydraulic system inoperative
Corresponding surfaces (slats or flaps) operate at half speed
69
ATA 27
| Consequence of 1 SFCC inoperative
Slats and flaps operate at half speed using the other SFCC
70
ATA 27
| Flap disconnect detection system
* Detects attachment failure and inhibits flap operation inorder to prevent further damage
* A sensor detects the failure by measuring excessive differential movement between inner and outer flaps
71
ATA 27
| Flight control computer architecture
```
• 2 Elevator Aileron Computer (ELAC):
- Normal elevator and stabilizer control
- Aileron control
• 3 Spoilers Elevator Computer (SEC):
- Spoilers control
- Standby elevator and stabilizer control
• 2 Flight Augmentation Computer (FAC)
- Electrical rudder control.
```
72
ATA 27
| Flight Control servojacks operation
• Servojacks are electrically-controlled hydraulic motors that drive the flight controls using 3 control modes:
- Active: Jack position is electrically-controlled
- Damping: Jack follows surface movement
- Centering: Jack is hydraulically retained in the neutral position
• Normal operation:
- 1 is in Active mode
- 1 is in Damping mode
73
ATA 27
| Flight control surface movements
* Electrically-controlled
* Hydraulically-activated
* Stabilizer and rudder can also be mechanically-controlled
74
ATA 27
| Flight Control, servojack failure and reconfiguration modes for Ailerons
* If Active servojack fails, the other one becomes active, and the failed jack is switched to Damping mode
* If neither jack is being controlled electrically or hydraulically, both switch to Damping mode
75
ATA 27
| Flight Control, servojack failure and reconfiguration modes for Elevators
* If Active servojack fails, the other one becomes active, and the failed jack is switched to Damping mode
* If neither jack is being controlled electrically, both switch to Centering mode• If neither jack is being controlled hydraulically, both switch to Damping mode
76
ATA 27
| Functions of the FAC
```
• Electrical rudder control:
- Rudder trim
- Rudder travel limiter
- Yaw damper
• Flight Envelope functions:
- Speed computation
- Low energy detection
- Windshear detection
```
77
ATA 27
| Grounds spoiler automatic logic on Rejected Take off
Speed above72 kt and:
• Ground spoilers armed, automatic extension when both thrust levers are set to idle
• Ground spoilers not armed, automatic extension when at least 1 engine is at reverse (remaining engine at idle)
78
ATA 27
| Indications if wing tip brakes are applied on flaps
```
• Slat/Flap position indicator:
- F legend becomes Amber
- Flaps indicated position turns Amber
- F LOCKED Amber appears at the bottom
• ECAM:Caution F/CTL FLAPS LOCKED
```
79
ATA 27
| Maneuver Load Alleviation system
• MLA system is available when:
‐ Normal or Alternate law
‐ Aircraft speed above 200 kt
‐ FLAP lever in position 0
- Load factor is more than 2 g
• MLA redistributes lift over the wing to relieve structural loads on outer wing surface (bending moment):
‐ Spoilers 4, 5 and ailerons are symmetrically deflected upwards
‐ Elevator is simultaneously applied to compensate for the pitching moment induced by spoilers and ailerons.
80
ATA 27
| Protections on Flaps/Slats system
* Auto retract
| * Alpha Lock
81
ATA 27
| Speed Brake surface failed on one side
The symmetric surface on the other wing is inhibited
82
ATA 27
| Speedbrakes inhibited in flight, How can they be re-deployed
• Once the inhibiting condition disappears:
- Speedbrake lever stowed
- Wait 10 seconds
- Try again
83
ATA 27
| Which hydraulic systems power the slats/flaps
* Slats: Green&Blue
| * Flaps: Green&Yellow
84
ATA 27
| “SPEED BRK” ECAM memo
* Green when speedbrakes are extended
| * Amber when speedbrakes should be retracted
85
ATA 27
| Speedbrake extension inhibition and automatic retraction
* SEC1 and SEC3 both faulty
* L or R Elevator faulty
* Angle of Attack or Alpha Floor protection active
* Flaps in conf FULL A320, conf 3 or FULL A321
* Thrust levers above MCT
86
ATA 27
| Ground Spoiler Automatic Logic for Landing
• Ground spoilers armed and all thrust levers at idle
- Automatic extension when both main landing gears have touched down
• Ground spoilers not armed and both main landing gears have touched down
- Automatic extension when at least 1 engine is at reverse (remaining engine at idle)
87
ATA 27
| Indications when CM1 uses the stick takeover pb and CM2 stick at neutral
* Aural “PRIORITY LEFT”
| * F/O Red Arrow light ON
88
ATA 27
| Indications when CM1 uses the stick takeover pb and CM2 stick not at neutral
* Aural “PRIORITY LEFT”
* F/O Red Arrow light ON
* CAPT Green light ON
89
ATA 27
| Roll Control
* 1 aileron and 4 spoilers on each wing control the aircraft on the roll axis
* Ailerons extend 5° down when flaps are extended (aileron droop)
90
ATA 27
| Spoilers, which pairs are used for ground spoiler, speedbrakes and turn
* Spoilers 1 to 5 act as ground spoiler
* Spoilers 2, 3 and 4 are used as speedbrake
* Spoilers 2, 3, 4 and 5 are used for roll, roll function has priority over speedbrake
91
ATA 28
| Center Tank transfer valve control logic on A321
• MODE SEL position MAN:
- Center tank transfer valves are open
- CTR TK XFR pb-sw must be selected OFF when:
. Wing tanks are Full to prevent an overflow
. Center tank is empty
• MODE SEL position AUTO, the Fuel Level Sensing Control Unit (FLSCU) controls the transfer valve open except in following conditions:
- Wing tank is full, until underfull sensor (Full-250kg)
- 5 mins after Centre Tank Low level sensor is activated
92
ATA 28
| Fuel crossfeed
• 1 cross feed valve controlled by a double motor allows:
- Both engines to be fed from one side or
- 1 engine to be fed from both sides
• When valve is open:
- Overhead panel, OPEN light ON in Green
- E/WD, FUEL X FEED Memo displayed in Green
- ECAM Fuel page, X-feed indication is Green In-Line
93
ATA 28
| Fuel Feed Sequence on A320
Tanks empty as follow:
1. Center tank
2. Inner tanks: Each inner tank empties down to 750 kg 3. Outer tanks: Fuel transfers into the inner tanks
94
ATA 28
| Fuel Feed Sequence on A321
• Wing tanks only can feed fuel to the engines
• Tanks empty in the following sequence:
1. Center tank, Fuel transfers into the wing tanks
2. Wing tanks
95
ATA 28
| Fuel Gravity feeding
* Suction valves, closed by pumps pressure in normal operation allow engines to be fed by gravity if Inner/Wing tank pumps fail
* Inner/Wing Tanks are the only tanks fitted with suction valves and gravity feeding can only be done from Wing Tank; CTR Tank Fuel is lost
96
ATA 28
| Fuel Pumps control logic on A320
• Inner tank pumps:
- ON throughout the flight
- Fitted with pressure relief sequence valves to ensure that when all pumps are running, Center tank pumps feed the engines
• Center tank pumps:
- Manual mode, pumps are ON
- Auto mode, pumps are ON except in following conditions:
- Slats are extended
- Inner TK is Full, until underfull sensor (Full-500kg)
- 5 mins after Centre Tank Low level sensor is activated
97
ATA 28
| Fuel quantity indication boxed in amber,
* Outer indication boxed amber if both transfer valve fail to open and inner at low level
* Center tank indication boxed amber if both Center tank pump fail or are switched off
98
ATA 28
| Fuel quantity, Amber line across last 2 digits
```
• FQI in degraded mode
• Loss of accuracy resulting depends on affected tank:
- A320&A321
. All tanks: +390 Kg, -750 Kg
. Center: +/- 130 Kg- A320
. Wing outer: +20 Kg, -200 Kg
. Wing inner: +/- 110 Kg- A321
. Wing: +/- 130 Kg
```
99
ATA 28
| Fuel Transfer from Outers to Inners, how does it work
* 2 transfer valves in each wing open automatically when inner tank fuel reaches low level (about 750 kg)
* Fuel is drained from the outer to inner all at once simultaneously in both wings
100
ATA 28
| Functions provided by the FLSCU/FQIC
```
• FQIC, Fuel Quantity Indicator Computer:
- Fuel quantity in each tank
- Fuel temperature
- Automatic refueling system
• FLSCU, Fuel Lever Sensing Computer system:
- Low/High Fuel quantity alerts
- CTR TK pump autofeed logic
- Outer to Inner transfer
```
101
ATA 28
| IDG Cooling
• Some of the fuel supplied to each engine:
- Goes from that engine high-pressure fuel line to the IDG heat exchanger
- Cools down the IDG oil temperature and then
- Recirculates through the return valve to the outer/Wing fuel tank
• This operation ensures the IDG cooling at low enginepower and when IDG oil temperature is high
• FADEC controls the fuel return valve
102
ATA 28
| Fuel Amber Fault light on a Pump pb-sw
Comes ON when the pump is in operation and the delivery pressure drops
103
ATA 28
| Fuel Amber Fault light on MODE SEL pb-sw
Comes ON when:
- MODE SEL pb-sw is at AUTO and
- Center tank has more than 250 kg of fuel and the left or right wing tank has lessthan 5 000 kg
104
ATA 28
| Fuel Amber Fault light on CTR TK L(R) XFR pb-sw
Comes ON when associated wingtank overflows
105
ATA 28
| Fuel system functions
• A320 and A321:
- Storing fuel in the tanks
- Supplying fuel in correct quantities to the tanks during refueling
- Supplying fuel to the engines and the APU
- Circulating fuel to cool the IDGs
• A320 only:
- Keeping fuel in the outer tanks for wing bending and flutter relief
106
ATA 28
| Fuel Tanks arrangements on A320/A321
```
• A320, Total 18 728 kgs
- 2 Outer Tanks: 2x 691 kgs
- 2 Inner Tanks: 2x 5 435 kgs
- 1 Center Tank: 6 476 kg
• A321, Total 18 605 kgs
- 2 Wing Tanks: 2x 6 084 kgs
- 1 Center Tank: 6 437 kg
```
107
ATA 29
| Hydraulic Blue pump operation
* Electrical pump automaticly starts after first engine start and stops after last engine shutdown
* Deactivated through the maintenance panel
108
ATA 29
| Hydraulic Amber Fault light on ENG Pump pb-sw
• Comes on when:
- Reservoir level is low
- Reservoir overheats
- Reservoir air pressure is low
- Pump pressure is low (inhibited on ground when the engine is stopped)
• Goes out when:
- Crew selects pb-sw OFF except for overheat where light stays until overheat is finished
109
ATA 29
| Hydraulic Amber Fault light on PTU pb-sw
• Comes on when:
‐ Green or Yellow reservoir overheats
‐ Green or Yellow reservoir low air pressure
‐ Green or Yellow reservoir low flluid level
• Goes out when:
- Crew selects pb-sw OFF except for overheat where light stays until overheat is finished
110
ATA 29
| Hydraulic OVHT or LO LVL in G/Y Hydraulic system, why do you need to switch off the PTU immediately
Prevent the PTU from running the faulty hydraulic system, thereby overheating the PTU itself and ultimately leading the good hydraulic system into an overheat condition
111
ATA 29
| Blue Hydraulic system main users
* Emergency Generator
* Slats
* Rudder
* Flight Control surfaces
112
ATA 29
| Green Hydraulic system main users
* Landing Gear
* Slats&Flaps
* Normal Brakes
* Rev Eng 1
* Yaw Damper 1
* Stabilizer
* Flight Control surfaces
113
ATA 29
| Hydraulic accumulator
1 accumulator in each system helps to maintain a constant pressure by covering transient demands during normal operation
114
ATA 29
| Hydraulic priority valves
Priority valves cut off hydraulic power to heavy load users if hydraulic pressure in a system gets low
115
ATA 29
| Hydraulic reservoir pressurization
* HP bleed air from engine 1 pressurizes the hydraulic reservoirs automatically
* If bleed air pressure is too low, crossbleed duct air pressure is used
* Pressure is high enough to prevent pumps from cavitating
116
ATA 29
| Power Transfer Unit (PTU) inhibition conditions
* First Engine start
| * Operation of cargo doors
117
ATA 29
| Power Transfer Unit (PTU) operation
* Enables Yellow system to pressurize the Green
* Enables Green system to pressurize the Yellow
* Starts automatically when differential pressure between Green and Yellow is greater than 500 PSI
118
ATA 29
| Ram Air Turbine (RAT)
* Pressurizes Blue system if electrical power is lost or both engines fail
* Deploys automatically if AC BUS 1&2 are both lost
* Can be deployed manually from the overhead panel
* Can be stowed only when the aircraft is on the ground
119
ATA 29
| Yellow Hydraulic system main users
* Flaps
* Alternate Braking
* Parking brake
* Rev Eng 2
* Yaw Damper 2
* Rudder
* Stabilizer
* Nose Wheel Steering (newer than B-HSO, older on Green)
* Flight Control surfaces
120
ATA 29
| Yellow Hydraulic system pressurization
* Pump driven by engine 2
* Electric pump
* Hand pump to operate cargo doors when no electrical power is available
121
ATA 30
| Probes heating
• 3 independent Probe Heat Computers (PHC) automatically control and monitor:
‐ Captain probes
‐ F/O probes
‐ STBY probes
• Electrical heating protects Pitot, Static, AOA, TAT
• On the ground, TAT probes are not heated and pitot heating operates at a low level
122
ATA 30
| What happen to the engines when Engine anti ice is selected ON
* Air from the high pressure compressor protects each engine nacelle
* EPR limit is automatically reduced and, if necessary, idle EPR is increased in order to provide required pressure
* Continuous ignition is ON
123
ATA 30
| What happen to the engines when Wing anti ice is selected ON
• Pneumatic system delivers hot air through 1 valve in each wing to slats 3,4 and 5• EPR limit is automatically reduced, and the idle EPR isautomatically increased
124
ATA 30
| Which part of the aircraft are equipped with antiicing
```
• Hot air:
‐ 3 outboard slats of each wing
‐ Engine air intakes
• Electrical heating:
‐ Flight compartment Windows
‐ Sensors, probes and static ports
‐ Waste-water drain mast
```
125
ATA 31
| Computers used by the ECAM
• DMC: Drive Display Units
• SDAC, acquire data and send signals to:
- DMCs to display synoptics and Engine parameters- FWCs to generate ECAM msg and aural alerts
• FWC, acquire data from SDACs and A/C sensors to:
- Generate alert messages, memos, aural alerts
- Flight phases
- RA, DH/MDA call outs
- Generate Red Warnings with data acquired directly by aircraft sensors
- Generate Amber Cautions with data acquired by SDACs
126
ATA 31
| DMC to Display Unit Relationship in normal configuration
* DMC1: CAP PFD&ND + ECAM DU
* DMC2: FO PFD&ND
* DMC3: Standby Backup
127
ATA 32
| BSCU receives orders from
* Captain and FO steering hand wheels (orders added)
* Rudder pedals
* Autopilot
128
ATA 32
| GEAR NOT DOWN ECAM Warning conditions
```
L/G not downlocked and:
• RA < 750 ft and
- Both engines, N1 < 75 %
- 1 engine, N1 < 97 %
• Both engines not at Take-off power and flaps not at 0
• Both RA failed and Flaps 3 or FULL
```
129
ATA 32
| Landing Gear gravity extension, consequences
• Approach:
- Gear extension, use QRH
- Gear doors stay down, Speed limited to 250 kts
• Missed approach:
- No Gear retraction, Select speed below 250 kts
130
ATA 32
| Speed for the landing gear safety valve
260kt
131
ATA 32
| When does the Steering system receives actuating hydraulic pressure
* Aircraft on ground
* At least 1 engine running
* A/SKID&N/W STRG switch ON
* Towing control lever in normal position
132
ATA 32
| Red arrow on the Landing Gear selector lever
Gear is not locked down when the aircraft is in landing configuration
133
ATA 32
| Red triangle on WHEEL Page
LGCIU detects a landing gear in transit
134
ATA 32
| Which Brake function is lost when Braking system degrades to Alternate with antiskid
AutoBrake function is inoperative
135
ATA 32
| Alternate brake without antiskid
• Anti-skid system can be deactivated:
‐ Electrically, A/SKID & N/W STRG sw OFF or power failure or BSCU failure
- Hydraulically,G+Y low pressure (accumulator only)
• Brake pressure is indicated on the triple indicator:
- BHSO and newer auto limited to 1000 PSI
- Older aircraft, pilot must refer to the indication to avoid locking a wheel
136
ATA 32
| Antiskid system operation
• The speed of each main gear wheel (given by a tachometer) is compared to the aircraft reference speed
• When the speed of a wheel decrease below 0.87 timesof reference speed, release orders are sent to normal and alternate servovalves to maintain wheel slip at that value for best braking efficiency
• Reference speed determined:
- Normal operation, by BSCU from horizontal acceleration of ADIRU 1, 2 or 3
- ADIRU all failed, equals the maximum of either main landing gear Wheel speeds
137
ATA 32
| Autobrake settings
• LO:
- Brakes 4 s after ground spoilers deployment
- Decelerate rate of 1.7 m/s²
• MED:
- Brakes 2 s after ground spoilers deployment
- Decelerate rate of 3 m/s²
• MAX: Maximum pressure goes to the brakes as soon as the system generates ground spoiler deployment order
138
ATA 32
| Autobrake system activation
* LO and MED mode, Command for ground spoiler extension
| * MAX mode,Command for ground spoilers extension and aircraft speed above 40 kt ( Ground spoilers extend above 72 kt)
139
ATA 32
| Autobrake system, arming conditions
```
LO, MED or MAX pb-sw pressed and:
• Green pressure available
• No failure in braking system
• At least 1 ADIRS functioning
• Anti-skid system has electric power
```
140
ATA 32
| Automatic switching of BSCU
* Landing gear lever selected DOWN
| * 1 channel fails
141
ATA 32
| Automatic switching of LGCIU
* Completion of retraction cycle
| * In case of failure.
142
ATA 32
| Braking failures mode revertions for B-HSO and newer aircraft
• Alternate braking with antiskid:
- Braking is controlled by the Alternate Braking Control Unit (ABCU)
- Antiskid is controlled by the BSCU
• Alternate braking without antiskid:
Fully-controlled by ABCU
• Alternate braking without antiskid on accumulator:
Fully-controlled by ABCU
143
ATA 32
| Braking operation
* Normal system uses Green hydraulic pressure whereas alternate system uses Yellowsystem backed up by the hydraulic accumulator
* Normal operation a dual channel Brake and Steering Control Unit (BSCU) controls normal braking and antiskid
144
ATA 32
| BSCU functions
* Normal Braking• Alternate Braking on old aircraft
* Controls the antiskid
* Checks brake residual pressure
* Monitors brake temperature
* Provides wheel speed information to other systems
145
ATA 32 Functions of the LGCIU
* Control extension/retraction of the gear and operation of the doors
* Supply information about the landing gear to ECAM for display
* Send signals to otheraircraft systems to indicate flight/ground mode
146
ATA 32
| Green DECEL light on the auto brake pushbutton
Actual deceleration is 80 % of selected rate
147
ATA 32
| Landing Gear emergency extension, operation
Pull the gear crank out and turn clockwise for 3 turns, this:
• Isolates landing gear hydraulics from Green system
• Unlocks landing gear doors and main&nose gear
• Allows gravity to drop the gear into extended position
148
ATA 32
| Landing Gear Indication panel
* Connected to LGCIU 1 which receives signals from proximity detectors
* If 1 indication remains UNLK, position can be confirmed using WHEEL SD page, 1 green triangle on each gear is sufficient to confirm that gear is downlocked
149
ATA 32
| Landing Gear, consequence on operation if ADR 1 + 3 fail
Landing Gear Safety Valve is controlled closed:
• Landing Gear retraction is inoperative
• Landing Gear Extension must be performed by gravity
150
ATA 32
| Red UNLK lights on Landing Gear Indicator panel
Gear is not locked in the selected position
151
ATA 32
| Under what speed is antiskid system automatically deactivated
20 kts
152
ATA 32
| What information does the LGCIU receive
```
The LGCIUs receive position information from:
• Landing gear:
‐ Gear locked down/up
‐ Shock absorbers compressed/extended
‐ Landing gear door open/closed
• Flaps
• Cargo doors
```
153
ATA 32
| Nosewheel Steering
* Controled by electrical signals from the BSCU (Pedal, CAP/FO handwheels, AP)
* Powered by Yellow Hydraulic
154
ATA 34
| ADR/IR, what information do they provide
```
• ADR (Air Data Reference):
- Barometric altitude
- Airspeed
- Mach
- AOA
- Temperature
- Overspeed warnings
• IR (Inertial Reference):
- Attitude (ATT mode)
- Flight path vector
- Track
- Heading
- Accelerations
- Angular rates
- Ground speed
- Position
```
155
ATA 34
| Basic modes of the EGPWS
• EGPWS generates aural and visual warnings below 2 450ft RA (RA, means EGPWS is available in Cruise)
• 5 basic modes:
- 1. Excessive descent rate: "SINK RATE" "PULL UP"
- 2. Excessive terrain closure rate: "TERRAIN" "PULL UP"
- 3. Altitude loss in take off or Go Around: "DON'T SINK"
- 4. Unsafe terrain clearance: "TOO LOW TERRAIN", "TOO LOW GEAR", "TOO LOW FLAPS"
- 5. Excessive deviation below Glide : "GLIDESLOPE"
156
ATA 34
| Difference between GPWS and EGPWS
Enhanced GPWS incorporates basic GPWS functions with added features:
• Terrain Awareness Display (TAD):
- Computes a Caution and Warning Envelope ahead of the flight path using aircraft altitude, range to the nearest runway and its altitude, ground speed, and turn rate- When these envelopes conflict with terrain memorized in the database, an alert is generated
• Terrain Clearance Floor (TCF):
- An Envelope is stored in the database for each runway where terrain data exist
- TCF warns of a premature descent below this floor, regardless of the aircraft's configuration
• Runway Field Clearance Floor (RFCF):
- Provides an Envelope protection for runways that are significantly higher than the surrounding terrain
157
ATA 34
| TCAS, classification of intruders
• Other (White empty Diamond):
- Non threatening aircraft within 30NM
• Proximate (White filled Diamond):
- Non threatening aircraft closer than 6NM laterally and within ±1200 ft vertically
• Traffic Advisory (Amber filled Circle):
- Potential collision threat
- TAU < 20 to 48s of CPA (depending on altitude)
• Resolution Advisory (Red filled square):
- Real collision threat
- TAU < 15 to 35s of CPA (depending on altitude)
158
ATA 34
| TCAS, Pilot reaction time for RA
* Initial order: 5 seconds
| * Enhanced RA: 2,5 seconds"INCREASE CLIMB / DESCENT" or Reversal RA, "CLIMB CLIMB / DESCEND DESCEND NOW"
159
ATA 34
| TCAS, when are RA automatically inhibited and converted into TA
* Windshear message triggered
* Stall message triggered
* GPWS messages triggered
* Aircraft below 1 100 ft in climb and 900 ft in descent
* “Descend” RA below 1 200 ft AGL at takeoff or 1 000 ft AGL in approach
* “Increase Descent” RA below 1 450 ft
160
ATA 34
| TCAS, when are TA automatically inhibited
• Below 600 ft AGL in climb and below 400 ft AGL in descent
161
ATA 36
| Single Bleed operation
* Remaining Pack goes high flow
| * Procedure- X BLEED ON- PACK FLOW LOW
162
ATA 36
| Air Bleed selection
* Air is normally bled from the intermediate pressure stage (IP) of engine’s high-pressure (HP) compressor to minimize fuel penalty
* At low engine speed, when the pressure and temperature of the IP air are too low, the system bleeds air from the HP stage
163
ATA 36
| Air HP valve automatic closure situations
* Low upstream pressure
* Excessive upstream pressure
* Bleed valve closed electrically
* Overpressure upstream of the HP valve with wing anti-ice OFF, 2 packs ON and aircraft altitude above 15 000 ft
164
ATA 36
| Bleed Valve
Located downstream of the junction of HP and IP valves, it acts as a shut-off and pressure regulating valve and maintains delivery pressure at 45 ±5 PSI
165
ATA 36
| Amber Fault light on ENG BLEED pb-sw
```
• Comes on if:
‐ Overpressure downstream of bleed valve
‐ Bleed air overheat
‐ Wing or engine leak
‐ Bleed valve not closed:
. During engine start or
. With APU bleed ON
• Goes out if ENG BLEED pb-sw is OFF and fault has disappeared
```
166
ATA 36
| BMC Failure
```
• If 1 BMC fails, the other one monitors the bleed system and issues ECAM warnings for:
‐ Overpressure
‐ Overtemperature
‐ Wing leak
• Following warnings are lost:
- ENG BLEED LEAK for associated engine
- APU BLEED LEAK if BMC1 has failed
• Bleed valve does not close automatically
```
167
ATA 36
| Closure of Bleed Valve
```
• Pneumatically:
- Upstream pressure < 8PSI
- Return flow
• Electrically by means of:
- BLEED pb-sw
- ENG FIRE pushbutton
- BMC in following cases:
. Overtemperature
. Overpressure
. Leak
. Open starter valve
. APU bleed being ON
```
168
ATA 36
| Consequences of a APU Leak detection
• APU leak signal closes automatically:
- APU bleed valve (except during engine start)
- X-bleed valve (except during engine start)
• FAULT light on APU BLEED pb-sw comes ON
169
ATA 36
| Consequences of a Pylon Leak detection
• Pylon leak signal closes automatically:
- Bleed valve on related side
- X-bleed valve (except during engine start)
• FAULT light on Associated ENG BLEED pb-sw comes ON
170
ATA 36
| Consequences of a Wing Leak detection
• Wing leak signal closes automatically:
- Bleed valve on related side
- X-bleed valve (except during engine start)
- APU bleed valve if the leak is on left wing (except during engine start)
• FAULT light on Associated ENG BLEED pb-sw comes ON
171
ATA 36
| Engine Bleed system
• The aircraft has 2 similar engine bleed air systems
• 1 Bleed Monitoring Computer (BMC) controls and monitors each bleed system• Each system is designed to:
‐ select compressor stage to use as a source of air
‐ regulate air temperature‐ regulate air pressure
172
ATA 36
| Leak detection system
• Leak detection loops detect any overheating near the hot air ducts in:
- Fuselage for APU (single loop)
- Pylons (single loop)
- Wings (double loop)
173
ATA 36
| Pneumatic air sources
* Engine bleed systems
* APU load compressor
* HP ground connection
174
ATA 36
| Pneumatic air users
* Air conditioning
* Engine starting
* Wing anti-icing
* Water pressurization
* Hydraulic reservoir pressurization
175
ATA 49
| APU Fuel supply
* Supplied by left feed line from CTR TK / L INNER pumps
* If fuel feed pressure is low (loss of tank pumps or EMER ELEC), a dedicated pump supplies fuel for APU startup;This pump normally runs off the AC ESS SHED
176
ATA 49
| APU automatic shutdown conditions
* Fire (on ground only)
* Air inlet flap not open
* Overspeed
* No acceleration
* Slow start
* EGT overtemperature
* No flame
* Underspeed
* Reverse flow
* Low oil pressure
* High oil temperature
* DC power loss (BAT OFF when aircraft on batteries only)
* ECB failure
* Loss of overspeed protection
177
ATA 49
| APU Electronic Control Box
```
Electronic Control Box (ECB) performs APU system logic:
• Sequence and monitor start
• Monitor speed and temperature
• Monitor bleed air
• Sequence shutdown
• Control automatic shutdown
```
178
ATA 49
| APU fire warning on Ground
* APU fire warning in cockpit
* Horn in nose gear bay
* APU AVAIL light goes out
* MASTER SW FAULT light ON
* APU auto-shutdown
* APU fire extinguisher discharges automaticaly
179
ATA 70
| Automatic continuous ignition
* Anti Ice ON
* TO Thrust selected
* Approach Idle
* In Flight Surge
* Master lever cycled ON/OFF
180
ATA 70
| Engine Idle Control
• Modulated idle:
- Regulated according to bleed system demand and ambient conditions
‐ Selected:
. On ground, provided reverse is not selected
. In flight when flaps are retracted (FLAPS lever at 0)
• Approach idle:
‐ Regulated according to aircraft altitude, regardless of bleed system demand
‐ Selected in flight, when flaps are extended (FLAPS not at 0)
‐ Allows the engine to accelerate rapidly from idle to go-around thrust
• Reverse idle:
‐ Selected on ground when thrust lever is in REV IDLE position
‐ Slightly higher than forward idle thrust
181
ATA 70
| Engine Start protection
* Provided by FADEC
* Available for automatic start on ground only
* Detects a hot start, a hung start, a stall or no light up
* Runs an abort sequence when N2 < 50 %
