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Flashcards in Flight Safety Systems Questions Deck (32):
1

The EMB 120 has how many generators?

5

2 x Main Generators
2 x Auxilary Generators
1 x APU Generator

2

How is the forward entry door raised and lowered?

The door normally raised hydraulically and lowered manually with hydraulic dampening.
However it can be raised manually from outside with help from ground staff.

3

Can the direct vision windows be removed by the
crew?

Yes.

In case of an emergency, due loss of visibility through main windshield or cockpit evacuation.

4

What happens if the main entry door is not securely closed and locked?

The FORWARD light on the DOORS panel illuminates.
The DOORS light on the MAP illuminates
Aural WARNING

5

How many cycles can the forward entry door be operated without recharging its accumulator?

4 Complete cycles.

6

What happens if the main entry door actuator remains pressurized after closing?

The door will be hydraulically blocked. Emergency valve in cockpit will need to be used to allow the door to be lowered.

7

How is AC electrical power provided?

2 x 250VA, 400Hz Static Inverters

8

What do the inverters convert 28VDC into?

115 and 26 VAC

9

Which buses do the inverters normally power?

Inverter #1 powers all 4 AC buses, Inverter #2 as
standby.

10

How many batteries are installed on the aircraft?

2

1 x 24VDC, 36 AH NiCad or Lead acid, Main battery.

1 x 24VDC, 5 AH Sealed Lead acid, backup battery.

11

Where are the batteries located?

In the nose of the aircraft, accessible through a panel just forward of the cockpit.

12

How are the batteries ventilated?

Forced airflow in flight.

13

How long will the main battery power essential loads?

Approx 30 Minutes

14

Is the battery always connected to the Hot Battery
Bus?

Yes.

15

What happens when you position the PWR SELECT switch to BATT? `

The battery contactor is is closed, connecting the battery to the central DC bus.

16

When will the battery contactor protection device open?

When the current from the central DC bus to the battery exceeds 500amps.

17

On the ground with the battery as the only power source what systems are inhibited by safety switch?

- Re-Circulation fans
- Gasper fans
- Ground cooling fans

18

What happens if the battery exceeds 70*C ?

- "Battery" Voice warning
- BATT OVERHEAT on MAP
- Master WARNING flashes

19

How many temperature sensing gauges are there for the Battery Temperature Monitoring System?

2 in the battery case.

1 provides signal to the gauge.
1 provides signal to the warning system.

(During test there may be a difference between warning activation and gauge temperatures)

20

What is the purpose of the backup battery?

Primary Purpose - Supply uninterupted power to standby horizon
Secondary purpose - Provide stabilized power supply to sensitive instruments during power transients such as battery start.

21

What is the rating of the Starter/Generators?

28VDC 400amps (600-Amps during engine start)

22

When does the GCU command the Starter to operate as a generator?

50% NH

23

During engine start which bus supplies the starters?

Central DC BUS

24

Which buses do the main generators directly supply?

Relay Box DC BUS 1 or 2, then DC BUS 1 or 2

25

What is the rating of the Auxillary Generators?

28VDC 150amps

26

What drives the respective Auxillary Generators?

Propeller reduction gearbox

27

At what Np do the auxillary generators connect to the electrical system?

> 70% Np

28

What is the rating of the APU generator?

Same as main generators, 28VDC 400amps

29

At what RPM is the APU generator able to provide nominal electrical power output?

95%

30

Can the APU and external power source both provide power to the central DC bus simultaneously?

No, EXT PWR has priority

31

Can the main generators and external power source both provide power to the central DC bus
simultaneously?

No , Main generator has priority

32

When will the overvoltage relay open to protect the central DC bus from, a over voltage in the external power?

32VDC