TEST

Question 1

What are the three characteristics of the PT6A Engine?

Answer 1

Light weight free turbine reverse flow

Question 2

What does Free Turbine mean?

Answer 2

An independent system that has no mechanical system and is only powered to driver the compressor turbines.

Question 3

What does Reverse Flow mean?

Answer 3

Airflow is circled around 2 times inside the Gas section

Question 4

hat is P3 in the engine?

Answer 4

compressor discharge

Question 5

) What is P2.5 in the engine?

Answer 5

Interstage Air

Question 6

What does black oil in the engine indicate?

Answer 6

It indicates that your carbon seal is deteriorating and depositing the dirt into the oil system. Change the seals

Question 7

• Interface between power section and gas generator section

Answer 7

Flange C

Question 8

• Power turbine vane assembly and power turbine

Answer 8

Flange D

Question 9

CT Vane Assembly and shroud housing

Answer 9

Flange E

Question 10

access to the compressor

Answer 10

Flange F

Question 11

• AGB access

Answer 11

Flange G

Question 12

Which of these flanges may be accessible by an overhaul shop only?

Answer 12

Flange A, B, F

Question 13

) Name the type of bearings located from 1 - 6:

Answer 13

Ball Roller Roller Ball Roller Ball

Question 14

) What type of loads do Ball Bearings take?

Answer 14

axial loads

Question 15

What type of loads do Roller Bearings take?

Answer 15

Radial loads

Question 16

) In what direction do the Compressor Turbines turn in?

Answer 16

CCW

Question 17

In what direction does the Power Turbine turn in?

Answer 17

CW

Question 18

What is the purpose of the master spline on the turbine disks?

Answer 18

Maintain balance with the shaft

Question 19

At what percentage of Ng does bleed valve close at?

Answer 19

91%

Question 20

What is the purpose and location of the Ng Tach Generator?

Answer 20

Purpose: Drives the the compressor in the Gas Generator Section (Gas Producer) - Location: Accessory Gearbox

Question 21

What is the purpose and location of the Nf Tach Generator?

Answer 21

• Purpose: Drives the propeller through the RGB - Location: Reduction Gearbox (RGB)

Question 22

What is the purpose and location of the Breather Impeller?

Answer 22

• Purpose: Vents breathed air overboard - Location: Accessory Gearbox

Question 23

What is the purpose and location of the Fuel Heater?

Answer 23

Purpose: Pre-heats the fuel to prevent ice crystal formation - Location: Accessory Gearbox

Question 24

What is the purpose and location of the Fuel Pump?

Answer 24

• Purpose: Boost fuel pressure to supply the fuel to the engine - Location: Inside FCU

Question 25

What is the purpose and location of the Torque-Meter?

Answer 25

- Purpose: Measures torque of rotating shaft - Location: Reduction Gearbox

Question 26

What is the purpose of the Accessory Gearbox?

Answer 26

- To drive the accessories mounted on it.

Question 27

What is the purpose of the Reduction Gearbox?

Answer 27

To reduce the RPM for the propeller. It is reduced because of the airframe capacity to take such a speed/RPM

Question 28

) How many stages are in this engine’s gearbox?

Answer 28

2 stages

Question 29

What is the gear ratio at 100%?

Answer 29

Tach drive runs at 4200 RPM @ 100%

Question 30

How many fuel nozzles are on a PT6? And what type?

Answer 30

- 10 Primary and 4 Secondary - Can be 7 and 7 as well - ALL ARE SIMPLEX

Question 31

What is the job of Oil in the engine?

Answer 31

To cool, clean and lubricate the bearings and propeller systems of the engine

Question 32

How much oil is consumed in the engine. Roughly

Answer 32

1 qt. In 10 hours of operation (MAXIMUM)

Question 33

How much is the oil pressure in the system?

Answer 33

80 to 100 psi

Question 34

What bearings have labyrinth seals on them?

Answer 34

1,2,3,4

Question 35

What is the purpose of the ignition system?

Answer 35

To provide a heat source/ spark to ignite the air/fuel mixture for combustion

Question 36

What are the 2 types of igniters?

Answer 36

Glow Plug - Spark Type

Question 37

What do you do if igniters are dropped?

Answer 37

Throw them away and get a new one. Do not reuse as they can be damaged.

Question 38

What must be done to the exciter while servicing?

Answer 38

Remove the exciter input lead before the high tension leads

Question 39

What must be always done to the exciter box plugs while servicing?

Answer 39

Always cap them off to prevent anything from entering and damaging the box.

Question 40

What is the purpose of the fuel system?

Answer 40

To supply clean fuel to the engine at a sufficient pressure to allow the burning in the combustor.

Question 41

PT6 - power percentage divides on:

Answer 41

67% of power to drive compressor 33% of power to drive propeller

Question 42

Engine two major sections:

Answer 42

1. Gas generator section, also call [Gas producer Section] 2. Power Section