DSC ENG and Fuel

Question 1

What is operated by the accessory gear box ?

Answer 1

Oil feed pump
main eng fuel pump
fadec alternator
eng driven HYD pump
Eng driven GEN
pneumatic starter

Question 2

What control the ENG and what redundancy is available ?

Answer 2

2 Fadec which control the complete engine management
Each Fadec has two channels, one is active the other is on standby. In case of failure the other takes over.

Question 3

How many idle are available ?

Answer 3

• modulated idle (regulated by bleed demand and ambient condition)
• approach idle in flight when flaps are extended => Allow to rapidly accelerate from idle to go around
• reverse idle

Question 4

What function are perform by the FADEC ?

Answer 4

control of gas generator
protection against engine exceeding limits
power management
start sequence
thrust reverser control
fuel recirculation
transmission of eng parameter
detection, isolation and recording of failures

Question 5

How many start cycles can you do with NEO and CEO ? Do you have to pause between start ?

Answer 5

A start cycle is 3 start attempts
Pause of 60s between each cycle for NEO
Pause of 20s for CEO

Cooling of 15min after 3 failed cycles for NEO, 4 failed cycles for CEO

Question 6

At what N2 you must not run the Starter NEO, CEO ?

Answer 6

N2 63% for NEO

N2 20% for CEO

Question 7

Flex takeoff, what is the highest temp for the FLEX (TMAXFLEX) ? A319,A320, A320NEO, A321 NEO ?

Answer 7

A319 TMAXFLEX : ISA+60°C
A320 CEO : ISA+53°C
A320 NEO : ISA+55°C
A321 NEO : ISA+52°C

Question 8

What system allow transfer from outer to inner ?

Answer 8

2 electric transfer valves mounted on each wings

Question 9

When will the transfer valves actives automatically ?

Answer 9

when fuel in the inner tank reach 750Kg in each wings

Question 10

Which valve control the fuel supply to the ENG ? and when will it close ?

Answer 10

the Low pressure fuel valve
ENG Fire PB and Master switch

Question 11

Can you gravity feed from the center tank ?

Answer 11

no

Question 12

What is the fuel sequence ?

Answer 12

1 center tank
2 Inner tank down to 750kg
3 outer tank: fuel transfers into the inner tank

Question 13

When will the transfer valve reset closed ?

Answer 13

next refueling

Question 14

What can happen when the center tank are feeding the ENG ? How is this prevented ?

Answer 14

the wing tank can overfill because of the fuel recirculation (IDG cooling) which return some of the fuel to the outer tank.
To prevent that, the system will turn off center tank pump until 500Kg has been used in the inner tank then restart the center tank pumps.

Question 15

What is the fuel recirculation ?

Answer 15

Fuel being used to cool down the IDG.
Once used the fuel will return to the outer tank, if full it will overflow to the inner tank.

Question 16

How is the fuel supplied to the APU ?

Answer 16

Special fuel pumps when fuel feed pressure is low. The fuel is coming from left fuel system.

Question 17

Can refuelling be done on batteries only ?

Answer 17

Have a BATT power toggle switch on the refuelling panel which when on allow refuelling on bat.

Question 18

What is the minimum temperature for JET A1 ? Max ?

Answer 18

Mini is -43°c
Max 54°C CEO, 55°C Neo

Question 19

What is the maximum Fuel imbalance for takeoff (inner tank balanced) ?

Answer 19

For A319/A320
Max asymmetry 370kg (a bit more than half outer tank capacity)

Question 20

What is the minimum fuel for takeoff ?

Answer 20

1500kg with no ecam low fuel for the wing tank