Lessons Lesson 1 of 3
Cold and dark to engine start
Power up the aircraft at a Heathrow stand, start the APU, prepare the flight to Manchester and start both engines — and understand what each system does.
START At a stand at London Heathrow, cold and dark, parking brake set.
34 STEPS · 7 BRIEFINGS · 14 READ FROM THE SIM · 13 YOU CONFIRM
Written, not yet flown through in the sim: that comes before the app does. Until then, steps and checks may still change.
How to read the colours Green: done or read from the sim. Cyan: your action and where to find it. Amber: caution. Magenta: a route constraint.
The scenario · INIT A, and the load
- FROM/TO
- EGLL/EGCC
- ALTN
- EGGP
- FLT NBR
- RSC101
- COST INDEX
- 30
- CRZ FL
- FL180
- ZFW
- 56.0 t
- BLOCK FUEL
- 4.0 t
Every step, with its reason
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BRIEFING · 1 OF 34
What cold and dark means
The aircraft is completely unpowered: no electricity, no hydraulics, no air. Everything we do in this lesson brings a system to life in a fixed order, because each one depends on the one before it. Batteries give us just enough power to start the APU. The APU gives us full electrical power and compressed air. And that compressed air is what turns the engines over when we start them. Today we fly from London Heathrow to Manchester. The steps follow the airline procedure, simplified for one pilot: a real crew is two pilots working from checklists.
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Step 2: Check PARK BRK is ON and the brake accumulator needle is in the green band
WHERE Pedestal, behind the thrust levers. Brake pressure gauge on the centre panel
You confirm this one
WHY
Before anything is powered, make sure the aircraft cannot roll. The parking brake works from a hydraulic accumulator, so it holds even with every system switched off, as long as the accumulator keeps its pressure. If the needle is low, the brake may not hold: keep the chocks in, and once there is power, switch on the yellow electric pump to recharge it. Later, when the engines start, the aircraft pushes forward a little, and the parking brake is what keeps it still.
The coach says: “Check the parking brake is on, and the accumulator pressure is in the green band.”
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BRIEFING · 3 OF 34
The electrical system in thirty seconds
The A320 runs mainly on alternating current, 115 volts, from one generator on each engine. Transformer rectifiers turn some of it into 28 volt direct current for the systems that need it. On the ground, before the engines run, the power comes from the APU generator or a ground power unit. Two batteries sit underneath it all. They are small: enough to start the APU and to keep the essential instruments alive in an emergency, but not to run the aircraft.
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Step 4: Read the battery voltage on the overhead panel, with BAT 1 and BAT 2 still OFF
WHERE Overhead panel, ELEC: the voltage display above the BAT pushbuttons
You confirm this one
WHY
With the batteries disconnected you see their true resting voltage. Above 25.5 volts they are charged enough to start the APU. Below that, a start could drain them halfway through and leave you with nothing, so the batteries must be charged first.
The coach says: “Read the battery voltage on the overhead panel, with both batteries still off.”
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Step 5: Press BAT 1 and BAT 2 (AUTO, OFF light goes out)
WHERE Overhead panel, ELEC
Read from the sim: BAT 1 ON · BAT 2 ON
WHY
Auto connects the batteries to the direct current buses. The cockpit comes partly alive: some lights, the ECAM in a reduced form, and the APU's controls. In auto the batteries also recharge automatically once the generators are running.
The coach says: “Batteries one and two, auto.”
CAUTION If this comes undone later, the coach says: “Caution. A battery is off again. BAT 1 and BAT 2 on.”
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Step 6: NAV & LOGO lights to 1 or 2
WHERE Overhead panel, EXT LT
Read from the sim: NAV ON
WHY
Navigation lights show other people which way the aircraft is facing: red on the left wing, green on the right, white at the tail. On the ground they also tell the ramp crew that the aircraft is powered and someone is in the cockpit.
The coach says: “Nav and logo lights on.”
CAUTION If this comes undone later, the coach says: “Caution. The navigation lights are off again.”
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BRIEFING · 7 OF 34
The APU: a small engine in the tail
The auxiliary power unit is a small jet engine in the tail cone. It does two jobs. Its generator powers the whole aircraft, and it delivers compressed air, called bleed air, for the air conditioning and for starting the main engines. With the APU running the aircraft is independent of the airport: no ground power, no air cart. It starts on battery power, which is why we checked the batteries first.
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Step 8: APU MASTER SWpress in (ON light comes on)
WHERE Overhead panel, APU section at the bottom
Read from the sim: APU MASTER ON
WHY
The master switch powers the APU's own computer and opens the air intake flap under the tail. Give the flap a few seconds to open before you press start: the APU cannot breathe through a closed intake.
The coach says: “APU master switch, on.”
CAUTION If this comes undone later, the coach says: “Caution. The APU master switch is off again.”
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Step 9: APU STARTpress and wait for AVAIL
WHERE Overhead panel, APU section
Read from the sim: APU speed ≥ 95 %
WHY
The battery spins the APU up, fuel is added and it lights. When it reaches about 95 percent speed it is stable and the green AVAIL light comes on. Watch the APU page on the lower ECAM: speed rising, exhaust temperature peaking and then settling. From now on the APU generator powers the aircraft and the batteries can rest.
The coach says: “APU start. Wait for avail.”
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BRIEFING · 10 OF 34
ADIRS: how the aircraft knows where it is
The A320 has three air data and inertial reference units. The air data part measures speed, altitude and angle of attack from probes on the nose. The inertial part uses laser gyros and accelerometers to measure every movement, and from that it knows attitude, heading and position without any outside help. But first it must align: it measures the earth's rotation to find true north, and it can only do that while the aircraft stands perfectly still. Until it is aligned, the attitude indicator and the map stay blank.
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Step 11: ADIRSturn IR 1, IR 3 and IR 2 to NAV
WHERE Overhead panel, ADIRS at the top left
You confirm this one
WHY
Nav starts the alignment. It takes several minutes, longer further north, so we start it now and do the rest while it runs. Do not move the aircraft until all three ALIGN lights are out. ON BAT only lights for a few seconds at the start, as a self-test. The third unit is a spare that can replace either side if one fails.
The coach says: “Set all three ADIRS to nav. While they align, we do the rest.”
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Step 12: APU BLEEDpress in (ON)
WHERE Overhead panel, AIR COND
Read from the sim: APU BLEED ON
WHY
This opens the valve that sends the APU's compressed air into the aircraft's air system. It does two things: the air conditioning packs can cool or heat the cabin, and the air is ready for the engine starters. Without APU bleed there is nothing to turn the engines over.
The coach says: “APU bleed, on.”
CAUTION If this comes undone later, the coach says: “Caution. APU bleed is off again. The engines need it to start.”
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Step 13: Fuel: check all six pushbuttons are ON, with no white OFF lights
WHERE Overhead panel, FUEL
You confirm this one
WHY
Four of the buttons are the pumps in the wing tanks, two in each. The other two are the centre tank transfer buttons: on the neo the centre tank has no pumps of its own, and its fuel is moved into the wing tanks, so the engines always feed from the wings. White OFF means a button is switched off. Amber FAULT means a pump is on but has lost pressure.
The coach says: “Check all six fuel buttons are on.”
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Step 14: SEAT BELTS to ON and NO SMOKING to AUTO
WHERE Overhead panel, SIGNS
Read from the sim: SEAT BELTS ON
WHY
The signs tell the cabin crew and passengers that departure is near. From pushback the aircraft can move or brake suddenly, so everyone must be seated with belts fastened. In auto, the no smoking and exit signs come on by themselves whenever the gear is down.
The coach says: “Seat belts on. No smoking, auto.”
CAUTION If this comes undone later, the coach says: “Caution. The seat belt signs are off again.”
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BRIEFING · 15 OF 34
The flight management system
The MCDU is your keyboard to the flight management system, the computer that knows the route and how the aircraft performs. You give it three things: where you are going, how you want to fly there, and the numbers for the takeoff. With that it computes speeds, fuel and the path. Later, in managed mode, the autopilot simply follows what the flight management system has computed. A mistake typed in here is flown faithfully, so every entry is cross-checked.
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Step 16: MCDU INIT AFROM/TO EGLL/EGCC, ALTN EGGP, FLT NBR RSC101, COST INDEX 30, CRZ FL 180
WHERE MCDU, INIT key
You confirm this one
WHY
From and to load the route between the two airports. The cost index is the trade between fuel and time: a low number flies slower and saves fuel, a high number flies faster when time costs more. The cruise level is low today because the flight is short, about forty minutes in the air, and this route is capped below flight level one ninety five.
The coach says: “On the init page: from EGLL to EGCC, alternate EGGP, flight number RSC one zero one, cost index thirty, cruise flight level one eight zero.”
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Step 17: EFB payload and fuel pages: load ZFW 56.0 (needs USE ZFW ENTRY on) and 4.0 t of fuel. Then MCDU INIT B: ZFW 56.0, ZFWCG from the EFB, BLOCK 4.0
WHERE EFB, payload and fuel pages. Then MCDU, INIT, NEXT PAGE
You confirm this one
WHY
The zero fuel weight is the aircraft with passengers and cargo but no fuel. Add the fuel and the computer knows the take-off weight, and every speed follows from it. Four tonnes is the trip to Manchester plus the reserves: enough to divert to Liverpool and to hold for thirty minutes, with a little extra.
The coach says: “On the EFB, load a zero fuel weight of fifty six point zero and four tonnes of fuel. Then on init B, enter the zero fuel weight, its centre of gravity from the EFB, and block fuel four point zero.”
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Step 18: MCDU F-PLNrunway 27R, SID UMLAT 1F (may be listed as UMLA1F), then T418 WELIN T420 ELVOS. Check there are no discontinuities before the arrival
WHERE MCDU, F-PLN key, then the departure airport (LAT REV → DEPARTURE)
You confirm this one
WHY
The SID, the standard instrument departure, is the published path from the runway into the airway system. It keeps departing traffic clear of terrain and of other aircraft. Heathrow's departures are flown by the flight management system, and this one stops at six thousand feet until air traffic control clears you higher. A discontinuity is a gap in the plan: the autopilot does not know how to get from one point to the next, and in managed mode it would simply fly straight ahead.
The coach says: “On the flight plan page: runway two seven right, the UMLAT one foxtrot departure, then the airways to ELVOS. Check there are no discontinuities.”
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Step 19: EFB TAKEOFFrunway 27R, CONF 1+F, then Calculate and Send to FMGS. Check PERF TAKE OFF: V1, VR, V2, FLX TO TEMP, FLAPS/THS 1 (that is 1+F), TRANS ALT 6000
WHERE EFB, TAKEOFF page. Then MCDU, PERF key
You confirm this one
WHY
V 1 is the decision speed: below it you can still stop on the runway, above it you are committed to fly. V R is where you rotate. V 2 is the safe climb speed if an engine fails. The flex temperature tells the engines to make the thrust they would make on a hotter day. That is less thrust than maximum, but still enough for this runway and weight, and it saves a lot of engine wear.
The coach says: “Run the take-off calculation on the EFB and send it to the FMGS. Then check the take-off page: the V speeds, the flex temperature, flaps one, the trim, and transition altitude six thousand.”
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Step 20: FCUset 6000, the departure's stop altitude
WHERE Glareshield, FCU: altitude knob
Read from the sim: FCU ALT 5,950–6,050 ft
WHY
The altitude on the F C U is a hard ceiling. Even in managed mode the aircraft levels off there and waits for you to set a higher one. That is how you obey air traffic control: they clear you to an altitude, you set it, and the aircraft cannot bust it.
The coach says: “Set six thousand on the FCU: the departure's stop altitude.”
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Step 21: BARO REFset the airport QNH on both sides and on the standby instrument. Check the altimeters agree within 20 ft
WHERE EFIS control panels on the glareshield: baro knob. Standby instrument on the centre panel
Read from the sim: Captain's baro on QNH · Captain's QNH within 1.5 hPa of the sim's QNH
WHY
Q N H makes the altimeter read height above sea level here, today. Every hectopascal you get wrong is about thirty feet of error, so a wrong setting can put you hundreds of feet lower than you think.
The coach says: “Set the airport QNH from the ATIS on both sides, captain and first officer, and on the standby instrument. Check the two altimeters agree within twenty feet.”
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Step 22: ADIRScheck all three ALIGN lights are out
WHERE Overhead panel, ADIRS
You confirm this one
WHY
The inertial units cannot align while the aircraft rolls, and without them there is no attitude, heading or map. So the aircraft does not move until all three are aligned.
The coach says: “Check all three ALIGN lights are out before we move.”
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Step 23: EFB GROUNDclose all doors, remove the ground power and the chocks. Check every door shows closed on the ECAM DOOR page
WHERE EFB, GROUND page. Lower ECAM, DOOR page
You confirm this one
WHY
An open door, a connected ground power unit or a forgotten chock are the classic things that stop a pushback. The door page shows every door and hatch, and all of them must be closed before the aircraft moves.
The coach says: “Close all doors on the EFB ground page and check every door shows closed on the lower ECAM door page. Remove ground power and the chocks.”
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BRIEFING · 24 OF 34
Pushback
In this lesson we start the engines at the stand. At Heathrow you would usually be pushed back first: on the E F B ground page you call the tug, choose left, right or straight back, and release the parking brake. The tug steers. You may start the engines during the push, engine two first. When the tug stops, parking brake on. Today, keep the parking brake set: we push back in the next lesson.
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Step 25: BEACON to ON. Check PARK BRK is still ON
WHERE Overhead panel, EXT LT
Read from the sim: BEACON ON · PARK BRK ON
WHY
The flashing red beacon means engines are starting or running, or the aircraft is about to move. It goes on with the pushback or start clearance and goes off only when the engines have spun down at the gate. When an aircraft arrives, the ground crew wait for it to go off before they come near.
The coach says: “Beacon on. Check the parking brake is still set.”
CAUTION If this comes undone later, the coach says: “Caution. The beacon or the parking brake is off. Both stay on while the engines start.”
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Step 26: Thrust levers: check both at IDLE
WHERE Pedestal, thrust levers
You confirm this one
WHY
If a lever is forward of idle when the engine lights, the engine runs up to that thrust against the brakes. With a hardware throttle, a lever left forward from the last flight is easy to miss.
The coach says: “Thrust levers: check both at idle.”
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BRIEFING · 27 OF 34
How an Airbus starts its engines
Each engine has a computer called FADEC, full authority digital engine control, which runs the whole start. When you select a master switch on, FADEC opens the start valve and APU bleed air spins the engine's starter. As the engine speeds up, FADEC switches on the igniters, adds fuel at the right moment and watches the exhaust temperature. If the start goes wrong, too hot or not accelerating, FADEC aborts it on its own. Your job is to watch the engine page and be ready to act if it does not.
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Step 28: ENG MODE selector to IGN/START
WHERE Pedestal, between the ENG MASTER switches
Read from the sim: ENG MODE IGN/START
WHY
This arms the start sequence and brings up the engine page on the lower ECAM, so you can see N 2, fuel flow and exhaust temperature. Nothing starts yet: each engine starts only when its own master switch goes on.
The coach says: “Engine mode selector to ignition start.”
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Step 29: ENG 2 MASTER to ON and wait until engine 2 is stable at idle
WHERE Pedestal, ENG MASTER 2
Read from the sim: Engine 2 running · Engine 2 N2 ≥ 50 %
WHY
Engine 2 goes first because its hydraulic pump pressurises the yellow system, which powers the nose wheel steering and the parking brake. Watch N 2, the speed of the engine's core, climb, then the fuel flow appear and the exhaust temperature rise and peak. The start is complete when everything settles at idle and the start valve closes. On the neo, a warm engine may turn on the starter for a while, sometimes more than a minute, before any fuel goes in. That is normal: don't abort the start.
The coach says: “Engine two master, on. Wait until engine two is stable at idle.”
CAUTION If this comes undone later, the coach says: “Caution. Engine 2 has stopped.”
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Step 30: ENG 1 MASTER to ON and wait until engine 1 is stable at idle
WHERE Pedestal, ENG MASTER 1
Read from the sim: Engine 1 running · Engine 1 N2 ≥ 50 %
WHY
The same sequence as engine 2. Engines are started one at a time so that all the bleed air goes to one starter, and so that you can give each start your full attention.
The coach says: “Engine one master, on. Wait until engine one is stable at idle.”
CAUTION If this comes undone later, the coach says: “Caution. Engine 1 has stopped.”
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Step 31: ENG MODE selector back to NORM
WHERE Pedestal
Read from the sim: ENG MODE NORM
WHY
Both engines are running, so the start sequence is no longer needed. In normal, FADEC still protects you: if an engine flames out, it relights it automatically.
The coach says: “Engine mode selector, normal.”
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Step 32: Pitch trim: set the THS from PERF TAKE OFF
WHERE Pedestal, the pitch trim wheels beside the thrust levers
You confirm this one
WHY
The trimmable horizontal stabiliser sets how nose-heavy the aircraft feels. The take-off value depends on the centre of gravity: set wrong, the nose comes up too early or too late at rotation, and the take-off config test warns you.
The coach says: “Pitch trim, set for take-off.”
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Step 33: ENG ANTI ICEON only below about 10 °C with visible moisture
WHERE Overhead panel, ANTI ICE
You confirm this one
WHY
Ice on the engine intake can break off into the fan, so the intake is heated with bleed air when ice can form: cold, and cloud, rain or snow. On a dry day it stays off, because the bleed air costs thrust and fuel.
The coach says: “Engine anti ice on only if it is below about ten degrees with visible moisture.”
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Step 34: APU BLEED to OFF
WHERE Overhead panel, AIR COND
Read from the sim: APU BLEED OFF
WHY
With A P U bleed on, the engine bleed valves stay closed and the A P U supplies all the air. Switching it off closes the A P U valve, the engine bleed valves open by themselves, and the engines take over. The A P U itself can keep running as a backup generator until after take-off.
The coach says: “APU bleed, off.”