TurboProp

Question 1

Turboprop most efficient operating speed

Answer 1

300-450mph

Question 2

How much total power can turboprop engines extract

Answer 2

95%

Question 3

What’s the name of a core engine

Answer 3

Gas generators or gas producer

Question 4

What is gas couple free turbine

Answer 4

No mechanical connection between gas generator and free power turbine

Question 5

What does propeller brake do

Answer 5

Prevent movement during aircraft loading when engine shut down not desired

Question 6

What happens when fuel flow changes in gear direct

Answer 6

Propeller pitch changes to maintain constant speed

Question 7

What’s constant at normal conditions gear/direct couple turbines

Answer 7

Propeller and fuel flow

Question 8

What’s different between gas/couple and gear/direct

Answer 8

Gear/direct has extra turbine discs

Question 9

What’s difficult about gear/direct

Answer 9

Needs complex integrated propeller control system to adjust propeller pitch

Question 10

How do turbo prop differ to turbo jet

Answer 10

Turbo prop fly’s at Lower speeds but more hostile environments

Question 11

What do inlet lips need

Answer 11

Large radius

Question 12

What does a particle separator do

Answer 12

Protect compressors by prevent ingress of dirt ….

Question 13

At what aircraft type has higher reduction ratio turbo prop or piston engine

Answer 13

Turboprop

Question 14

Pratt & Whitney reduction ratio

Answer 14

15:1

Question 15

33000 rpm how fast is the propeller rotating

Answer 15

200 rpm

Question 16

Why does turboprop need higher viscosity lubricants

Answer 16

Heavier loads on imposed engines

Question 17

What’s the problems with spur gears

Answer 17

Bulky and noisy & turbine shaft is offset

Question 18

What’s used to overcome spur gears

Answer 18

Spur epicyclic gears that give output drive on the same axis as the input shaft

Question 19

What’s a bevel epicyclic gear

Answer 19

Use bevel pinion (planet) gears

Question 20

Where are bevel epicyclic gears used

Answer 20

Piston engines

Question 21

What does the helical cut in spur epicyclic do

Answer 21

Reduce noise and vibration while providing a way to measure torque

Question 22

What is a spur epicyclic gear

Answer 22

Pinion gear rotates around a sun gear inside an annular ring gear

Question 23

What’s an advantage of compound spur epicyclic

Answer 23

Two stages high and low to provide greater speed without without needing larger components

Question 24

What does the low speed train have

Answer 24

Helical gears

Question 25

What does the high speed train have

Answer 25

High speed pinion

Question 26

What is rotating annulus

Answer 26

Rotates propeller in the opposite direction to which engineer is rotating

Question 27

What is variation in a compound spur epicyclic

Answer 27

Fixed annulus which rotates in the same direction as engine

Question 28

What is a two stage spur

Answer 28

Single input/output gear unit contained in triple housing

Question 29

What does input housing contain in atwo stage spur

Answer 29

First stage reduction gearing

Question 30

What is the single input/output manufactured from

Answer 30

Magnesium alloy

Question 31

Purpose of over speed saftey device

Answer 31

Used in first instance to coarsen blade angle if it fails then to reduce engine power

Question 32

What are the methods of over speed safety devices

Answer 32

Engine governer & free power turbine , over speed governor

Question 33

Why would an overspeed governer be re-datumed

Answer 33

Ground test purposes

Question 34

What is twin lever control components

Answer 34

Power lever & conditioning lever

Question 35

What does a power lever do

Answer 35

Control for engine power output in propeller constant speed mode & propeller blade angle directly in beta mode

Question 36

What is the propeller conditioning lever used for

Answer 36

Set propeller rpm in constant speed mode

Question 37

What is used to adjust propeller pitch in a single lever control

Answer 37

Complex control system

Question 38

What is engine power dependent on

Answer 38

Mass and temperature of gas flow into turbine