Engine & Propeller

Question 1

What engine is on the aircraft?

Answer 1

Honeywell TPE331-10

Question 2

What is the compressor/turbine configuration of the engine?

Answer 2

Two stage centrifugal compressor

Three stage axial turbine

Question 3

What is the shaft horsepower of the engine?
How much is used to drive the compressor?
How much to drive the propeller/accessories?

Answer 3

900 SHP
2/3 drives the compressor
1/3 drives propeller/accesories

Question 4

How much jet thrust is generated by the engine?

Answer 4

157 lbs at max continuous power

Question 5

What does the DEEC do?

Answer 5

Digital Electronic Engine Control provides control of all fuel and engine speed functions

Question 6

What is the DEEC lockout range?

Answer 6

89.5% - 92.5% and prevents operation in this RPM range by rounding up or down

Question 7

What are DEECs primary functions?

Answer 7

Fuel control
Engine speed control

Question 8

What are DEECs secondary functions?

Answer 8

Engine torque and temperature limiting (control fuel flow to limit engine from exceeding)
Engine speed switching (control engine events during start)
Automatic fuel enrichment (ensures no exceedance of 695 C EGT during start)
Single red line EGT (single red line of 650 C instead of having to use charts to calculate max EGT based on OAT and % RPM)
Closed loop power control (interpreted as percent of SHP instead of fuel flow for linear throttle response)
Engine and DEEC fault monitoring

Question 9

If the engine driven fuel pump fails will the engine continue to run normally?

Answer 9

No, the engine will lose power

Question 10

What are some engine considerations when operating in DEEC backup mode?

Answer 10

No automatic control of engine speed, torque, or EGT

Engine speed automatically set to 100%
Torque limited to 70% (torque limiting is disabled during launch and recovery so it is very easy to overtemp engine especially with full reverse thrust on landing)
Cruise mode = OFF

Question 11

How is propeller pitch controlled?

Answer 11

Engine oil pressure acting against a spring and counterweights

Engine oil drives propeller to a high RPM/low pitch setting
Spring/weights drive propeller to a low RPM/high pitch setting (feather)

Question 12

What happens to propeller pitch when engine is shut down?

Answer 12

As engine shuts down oil pressure is reduced
Spring/counterweights drive blades towards feather
Throttle must be set to full reverse prior to 40% RPM to engage lock pins to prevent propeller from going to full feather

Question 13

What may happen if an engine is started with the propeller feathered?

Answer 13

Hot start and damage to the starter

Question 14

What are the two modes of propeller control?

Answer 14

Flight and ground mode

Flight mode = throttle controls fuel flow and governor adjusts blade angle to maintain constant RPM
Ground mode = throttle controls blade angle and fuel is adjusted to maintain constant RPM

Question 15

Does the engine have an automatic feather system?

Answer 15

No, it has a negative torque sensing system.

The NTS system partially feathers the propeller blade. Pilot must select full feather using the condition lever.

Question 16

What is bleed air used for?

Answer 16

Purge the fuel manifold during engine shut down

If speed lever has not been placed to high since engine start then must be set to high (at least 96%) to charge fuel purge system

Question 17

Simultaneous use of reverse thrust and wheel brakes should be avoided below what speed?

Answer 17

10 kts because aircraft can tip back on its tail

(if aircraft is moving backward use forward thrust rather than brakes to stop the backward movement)

Question 18

What is the critical range RPM?

Answer 18

18-28%

Question 19

What is the airspeed and altitude envelope for an air restart?

Answer 19

Airspeed = 100-180 KIAS
Altitude = <30,000’