Technical knowledge

Question 1

For how many amps are generators rated?

Continuous + Engine start

Answer 1

300 amps > continuous
400 amps > Engine start

Question 2

What voltage does the GCU (Generator Control Unit) maintains on the DC bus?

Voltage & Tolerance

Answer 2

28.25 +/- 0.25 VDC

Question 3

Volt & amp-hr ratings on aircraft battery?

Answer 3

24 VDC
34 amps-hr

Question 4

What is an H.E.D.?

What makes it surge & where

Answer 4

Hall-Effect Device, bidirectional current-sensing device controlling its associated bus tie
(2x) 325 Amps on either GEN ties
(1x) 275 Amps on BATT tie

Question 5

Can you reset a popped circuit breaker?

which conditions (2)

Answer 5

Yes, only if it’s essential & after letting it cool for 3 minutes.

Question 6

Specifications for using external power?

Volts & Amps

Answer 6

• 28.0 to 28.4 VDC
• 300 amps (continu)
• 1000 amps (intermittent)

Question 7

What is a jet pump?

Answer 7

• Solid-state venturi
• Assists gravity feed fuel to flow :
  (2x) Transfer JP : main > collector
  (1x) Main tank JP : collector > engine

Question 8

How many fuel drains under each wing?

Answer 8

5

Question 9

XFR VALVE FAIL (amber)
+ FUEL TRANSFER (white)

In which position is the fuel cross-transfer valve ?

Answer 9

Fully OPEN

Question 10

What is the ACM?

Answer 10

Air-cycle-machine
Bleed air driving a compressor, using thermodynamics (pressure<>temperature) to heat, cool & pressurize cabin

Question 11

What is the VCM?

Answer 11

Vapor-cycle-machine
Augments ACM output when more cooling is required, using a closed Freon loop to cool down cabin

Question 12

Approx. nmbr of strokes to manually lower landing gear?

Answer 12

80-90 strokes

Question 13

After how many seconds does the timer turn off the gear pump?

Whats the use & Amps of the only gear CB?

Answer 13

16 +/- 0.5 sec
Gear control handle : 2 Amps

Question 14

How to confirm green gear lights aren’t burnt out

Answer 14

Annunciator test button

(HYD LT TEST = Handle lights only)

Question 15

What disables power to the flap motor

System & condition

Answer 15

Flap safety switch, adjacent to each set of wing flap pairs

When either flap in that pair is more than 3° to 6° out of phase with the adjacent flap.

Question 16

How long to wait between gear cycles?

Answer 16

2 minutes between the first 3 cycles, then 5 minutes between each cycles

Question 17

What holds gear extended?

Answer 17

Mechanical downlocks

Question 18

What holds gear retracted?

Answer 18

Hydraulic pressure

Question 19

When should you use beta range?

Answer 19

Taxi

Question 20

When can you lift a power in flight?

Answer 20

Never

Question 21

How can you tell you are operating on the overspeed governor?

Answer 21

RPM stabilizes at 1802, with props full forward

Question 22

If CTR bus fails, which important system fails?

Answer 22

Landing gear

Question 23

How are false fire alarm prevented?

Answer 23

Outside air temperature is monitored & there is a slight time delay factored in.

Question 24

When to turn on auto-ignition (2)

Answer 24

• Rain
• Turbulence

Question 25

Min. recommended engine oil temp. before T/O & for which reason?

Answer 25

55° Ensures operation of oil-to-fuel heat exchanger

Question 26

What triggers the gear warning horn? (2) | & Which one cannot be silenced?

Answer 26

Gear UP (or unsecure), along with : A) FLAPS > 17, regardless of power (cannot silence) B) FLAPS 0-17, with power < 84-86% N1 (descent)

Question 27

BUS SENSE switch : TEST | What it does & what it causes

Answer 27

* Sends ''test currect'' from the buses to all 3 HED * Causes GEN TIE OPEN + BATT TIE OPEN = Isolates CTR bus (0V)

Question 28

BUS SENSE switch : RESET | What it does & what it causes

Answer 28

* Deenergizes the control relays * Closes the BATT & GEN ties, extinguishing the annunciators = Reconnects wt CTR bus (28V)

Question 29

GEN TIES switch | Function

Answer 29

Manually controls the generators bus tie relay (between GEN buses & CTR bus)

Question 30

GEN TIE switch : MAN CLOSE

Answer 30

* Closes both gen bus ties, allowing current to flow from the CTR to the GEN buses (24V) * Illuminates MAN TIES CLOSE annunc. (green)

Question 31

GEN TIES swtich : OPEN

Answer 31

* Removes power from both gen bus ties = L&R GEN TIE OPEN (amber) illum. * Generators feed 28V to GEN buses & TPL bus only, disconnected from CTR (24V)

Question 32

L/R GEN TIE OPEN annunc. (amber) | Can you reset (or) close manually ?

Answer 32

GEN TIES switch : Cannot manually CLOSE when either gen tie opens due to a ground fault BUS SENSE switch : RESET may be attempted

Question 33

What results in a TPL bus isolation?

Answer 33

3 bidirectionnal 60 Amps current limiters have open (gen1/gen2/battery)

Question 34

Load shedding | If both GEN fail, which buses will the battery feed?

Answer 34

* GEN TIES will automatically OPEN * Battery feeds : TPL + CTR + HOT BATT