M11.6

Question 1

What is electrical power used for?

Answer 1

• electrical heating
• lighting
• electronic devices
• produce mechanical power

Question 2

How much electrical energy does a 2 engine aircraft need?

Answer 2

100Kw

Question 3

How much electrical energy does a 4 engine aircraft need?

Answer 3

400Kw

Question 4

What does a static inverter do?

Answer 4

It converts DC to AC

Question 5

What voltage and frequency is AC power?

Answer 5

115 volt

400 hertz

Question 6

What does a transformer rectifier unit do?

Answer 6

It transforms AC to DC

Question 7

What voltage does the DC power work on?

Answer 7

28 volts

Question 8

What are most batteries made from?

Answer 8

Nickel cadmium

Question 9

How much voltage does a battery provide?

Answer 9

24 volts DC

Question 10

What are batteries used for?

Answer 10

• engine starts
• APU starts
• emergency distribution

Question 11

What are the four things that supply AC power to the aircraft?

Answer 11

• engine generator
• APU generator
• external power
• emergency generator

Question 12

What supplies the aircraft with DC power?

Answer 12

Batteries

Question 13

What is a ‘bus’ used for?

Answer 13

It connects the power source to the consumers

Question 14

What does AC stand for?

Answer 14

Alternative current

Question 15

What does DC stand for?

Answer 15

Direct current

Question 16

What must be done when switching on/off power whilst on the ground?

Answer 16

Large loads must be switched off

Question 17

How long can a battery last as emergency power?

Answer 17

30 minutes

Question 18

What drives the air driven generator?

Answer 18

Ram air

Question 19

What drives the constant speed motor generator?

Answer 19

A hydraulic motor

Question 20

What is always powered?

Answer 20

Hot battery bus

Question 21

What is the main task of fuse or circuit breaker?

Answer 21

To prevent overheat or fire due to a short circuit

Question 22

What happens in a short circuit?

Answer 22

A current is larger than the maximum allowed cross section of the wire

Question 23

How does a fuse work?

Answer 23

A smaller cross section of metal is placed before the terminal to absorb the short circuit

Question 24

Why do most aircraft use circuit breakers over uses?

Answer 24

Because fuses are time consuming

Question 25

What does location of the circuit breaker depend on?

Answer 25

The location of the consumer to minimise wire length

Question 26

What is the basic fundamental of a generator?

Answer 26

A rotating magnets spins between a magnetic North and South Pole (pole pair)

Question 27

If a generator takes one second to complete one cycle, how many hertz does it produce?

Answer 27

A frequency of 1hertz

Question 28

How much voltage is produce in a ‘line to neutral’ (phase to ground)?

Answer 28

115v

Question 29

How much voltage is produce in a ‘line to line’ (phase to phase)?

Answer 29

200v

Question 30

During low speeds the constant speed drive will do what?

Answer 30

Speed up

Question 31

During high speeds the constant speed drive will do what?

Answer 31

Slow down

Question 32

What combines together to create the integrated drive generator?

Answer 32

Constant speed drive and a generator

Question 33

How many TRUs are there?

Answer 33

1 for each main DC bus

Question 34

What type of fluid is found in a battery?

Answer 34

Electrolyte fluid

Question 35

How often should a battery be check for operation?

Answer 35

2,000 hours

Question 36

What are the 6 pins on the external power plug for?

Answer 36

• 4 thick pins for phases A,B,C and neutral

- 2 thin pins to control connection