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Powerplant Flashcards

(49 cards)

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1
Q

How much SHP for Q200 (including up trim)

A

1950SHP uptrim to 2150SHP

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2
Q

How much SHP for Q300 (including up trim)

A

2140SHP uptrim to 2380SHP

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3
Q

How many sections to PW123D engine

A

3 sections (3 shafts)

Low Px Compressor (NL)
High Px Compressor (NH)

High Px Turbine
Low Px Turbine

2 stage Power Turbine

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4
Q

How is pressurised oil supplied to engine

A

Gear driven Oil Pump from Accessory Gearbox

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5
Q

How is heated Oil cooled

A

Oil is cooled by air in the engine intake duct
&
Cooled by a Fuel/Oil heat exchanger
(cold fuel will cool the oil)

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6
Q

If there is a catastrophic loss of engine oil can the prop still be feathered

A

Yes.

An independent reservoir of engine oil in the reduction gearbox is available to be used by the Auxiliary Feathering Pump

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7
Q

How is the Accessory gearbox driven

A

By a shaft connecting it to the Nh Compressor rotor

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8
Q

What does the Accessory Gearbox drive

A

FOD
Fuel Pump
Oil Pump
DC Starter/Generator

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9
Q

How is the DC Generator cooled

A

The DC Gen is air cooled

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10
Q

What is the Start process

A
  1. Starter cranks Nh rotor through 10-19%
  2. CL moved to START FEATHER to introduce fuel
  3. 25% Nh ECU takes control of fuel schedule (ground idle)
  4. ECU accelerates Nh to 76%
  5. Start sequence terminates at 63% Nh
  6. DC Starter/Generator changes to Generator mode
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11
Q

What does the Prop Reduction Gearbox drive

A

OPRAH minus the R

Hydraulic Pump
PCU
Overspeed Governor
AC Generator

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12
Q

In Beta mode what do the Power Levers control

A 
Engine Speed &
Blade Angle (direct input to PCU)
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13
Q

What are the 3 functions of the Condition Lever

A
  1. Introduce/Terminate fuel to the engine via shutoff
  2. Feathering of the propeller
  3. Constant speed governing of propeller via blade angle in forward thrust range (900-1200RPM)
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14
Q

What are the functions of the ECU

A
  1. Propeller Underspeed governing
  2. Propeller governing in reverse
  3. Fuel scheduling for ground idle
  4. Fuel scheduling in forward power range
  5. HBOV operation
  6. Quiet taxi mode
  7. Power up trim
  8. Tq signal to Tq indicators
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15
Q

How is fuel scheduling conducted in ECU MANUAL mode

A

Fuel scheduling will be fixed at point of failure

Fuel schedule then selected by Power Lever movement and Condition Lever movement

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16
Q

What happens to the Engine Tq when the ECU fails

A

Either no change or Tq will increase by 8-10%

There may be a split in PL to achieve symmetrical Tq

NOTE: No change before Climb Power set

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17
Q

What are the 2 indications that an ECU has failed or gone into MANUAL reversion

A

Caution lights #1 ENG MANUAL
AND
“MANUAL” in amber on ECU MODE control panel

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18
Q

What automatic functions are lost with an inoperative ECU

A

Np under speed protection

Uptrim

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19
Q

How does the ECU protect against Np under speed

A

The ECU keeps Np out of the restricted range (500-780RPM) by adding fuel to increase Nh, thus speeding up the prop

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20
Q

Where is the HBOV situated

Study These Flashcards
A

Inline with the Low Px Compressor (p2.5)

21
Q

What is the role of the HBOV

Study These Flashcards
A

It bleeds LP Compressor air to prevent Compressor stall and surge at low power settings
It also aids in reducing engine noise

22
Q

How does the Uptrim system work

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A
  1. Autofeather system is armed (Tq above 38% on both engines and PLA/OAT requirements satisfied
  2. Engine fails and Tq reduces to 28%
  3. Armed SCU detects 28% on inoperative engine and 38% on operative engine
  4. Triggered SCU sends power up trim signal to ECU on operative engine

3 second delay

  1. SCU of affected engine initiates AutoFx
  2. ‘Np under speed fuel governing cancel’ signal sent to inoperative engine ECU
  3. Auxiliary pump energised for 18 secs to allow feathering
  4. Interlock engages to prevent AutoFx of second propeller
23
Q

How much is power increased during up trim

24
Q

What are the 5 main components of the Propeller System

Study These Flashcards
A
  1. PCU
  2. Prop Overspeed Governor
  3. AutoFx system
  4. Alternate Fx system
  5. Synchrophase system
25
What are the 3 ways to feather the propeller
1. Automatic mode during AutoFx sequence 2. Manually moving CL to START & FEATHER 3. Using the Alternate Fx system
26
How does the PCU work
The PCU regulates oil px to a double acting pitch change mechanism inside the hub. Constant and Metered Oil px
27
What is metered oil referred as and what meters it
Fine Pitch Oil and is metered by the PCU
28
What is unmetered oil referred as
Constant Pitch oil (coarse)
29
Fine pitch oil drives the propeller...
To a lower pitch, reducing blade angle and increasing speed
30
Constant oil drives the propeller....
To a high pitch, increasing blade angle and decreasing speed ultimately to Fx
31
How is feathering accomplished
By dumping metered oil (fine pitch oil) allowing constant oil to drive the blade to Fx
32
Where is the Synchrophase system located
On the #2 PCU
33
How is a feathering prop indicated
Np reduces through the 12 o'clock position moving towards 0
34
How is a propeller feathered manually
1. Moving the CL to START & FEATHER 2. Manual feathering valve in PCU is opened 3. Metered oil is dumped
35
How does the Prop Overspeed Governor work
Hydraulically controlled in constant speed and flight beta at 1250RPM 1. Np exceeds certain value 2. Flyweight governor detects overspeed condition 3. POG dumps metered oil 4. Constant oil coarsens the blade towards feather 5. Prop is slowed aerodynamically
36
How does the Prop Overspeed Governor work on the ground
Pneumatically controlled in ground beta at 1308RPM 1. POG has pneumatic section for P3 air 2. P3 air is bled off 3. As MFC uses P3 air for fuel scheduling, fuel will be reduced 4. Prop is slowed down as engine slows down
37
How does the Beta Backup system work
1. A PCU malfunction causes the prop to enter beta ground range in flight 2. Beta Backup system will open Feather Solenoid valve 3. Metered oil (fine pitch) will be dumped 4. Propeller blade angle will begin to feather and increase out of ground range. 5. Once past the ground range point, the low blade angle switch closes the feather solenoid valve and the cycle continues.
38
If a loss of oil px were to cause the blade angle to begin to change angle by itself what will happen
The pitch lock will activate in the pitch change mechanism This will prevent aerodynamic loads from changing the prop more than 1 degree or by 2% in speed This can be overridden by using the Alternate Fx system
39
What will happen with an ECU in MANUAL mode on landing
As the PL are moved to flight idle the prop rpm will decrease into the restricted range. Normally the ECU would prevent this. High Tq will be required to keep the prop out of the restricted range, the prop should therefore be feathered during taxi.
40
Aerodynamic loads drive blade angle to...
Fine or low blade angles
41
When will the propeller ground range lights illuminate
When the low blade angle switch is activated by blade angle passing 16 degrees
42
When do the ENGINE INTAKE HEATERS come on
When the Bypass doors are open and the temp is below 15 degrees
43
How is heater operation prevented with the engine shut down
An oil px switch
44
What is the capacity of the Engine Oil system
6 USG
45
What is the capacity of the independent oil reservoir for Alternate Fx
1.7 US Quarts
46
When will the #1 ENG OIL PRESS warning light illuminate
42 +/- 2PSI
47
What path does the oil take throughout the engine
1. Sump 2. Oil pump 3. Oil cooler 4. Filter 5. PRV 6. Fuel Heater 7. Oil network 8. Reduction gearbox 9. PCU pump 10. Aux fx pump
48
What component of anti ice uses engine oil
The engine inlet splitter uses hot engine oil
49
How is oil returned to the sump
3 gear type scavenge pumps.

Dash 8 (7 decks)

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