Engine General

Question 1

What is the PT6A-67B engine rated at?

Answer 1

1600 SHP flat rated to 1200 SHP (shaft horsepower).

Question 2

How many axial compressors foes the engine have?

Answer 2

4.

Question 3

MOR lever has an initial dead band of how many degrees?

Answer 3

17.

MOR is used when FCU fails. There is a dead zone of 17 degrees while you move the MOR lever forward.

Question 4

What is the percentage of power generated by jet thrust from the exhaust stacks?

Answer 4

6%.

Question 5

Using feather inhibit allows for a lower ITT on next start in the summer.

Answer 5

True.

Question 6

How is the engine installed?

Answer 6

2 degrees down, 2 degrees right of the fuselage centreline. This counteracts torque.

Question 7

What sections are there of the engine?

Answer 7

Compressor
Combustion
Turbine
Prop reduction
Accessory gearbox

Question 8

What do the compressor sections consist of?

Answer 8

1. 4 stage axial compressor
2. Single-stage centrifugal impeller (compresssor rotor)
3. 4 static vane assemblies
4. Open mesh screen of the in,et protects the engine from debris

Question 9

What is the combustion section comprised of?

Answer 9

Provides an area for the mixture of air and fuel. Followed by the turbine section.

Question 10

What is the turbine section comprised of?

Answer 10

1. Compressor turbine which drives the compressor rotor and accessory gearbox
2. 2 power turbines which drive the reduction gearbox
3. Exhaust duct
4. Power turbine stators
   Note: compressor turbines rotate counterclockwise, power turbines rotate clockwise

Question 11

What is the propeller reduction gearbox comprised of?

Answer 11

1. It reduces power turbine speed to a speed suitable for propeller operation (governs it between 28,864RPM and 1,700RPM - 100% to 0%)
2. Provides gearing for 5e operation of the propeller governors

Question 12

What is the acessory gearbox?

Answer 12

1. Located at rear of the engine
2. Provides all gearing mounts for all engine-driven accessories, except the propeller governors.

Question 13

What are the engine modules?

Answer 13

Gas generator and power section.

Question 14

What is the gas generator comprised of?

Answer 14

• compressor section
• compressor turbine
• accessory gearbox

Induction and compression of air, mixing of fuel, and rotates the ACCESSORY gearbox

Question 15

What is the power section comprised of?

Answer 15

• gearbox
• power turbine

Direct combustion of gas and rotates the REDUCTION gearbox

Question 16

What are the two main engine modules?

Answer 16

Gas generator and power section

Question 17

How is the engine protected from FOD?

Answer 17

An air inlet screen within the engine assembly and an inertial separator.

Protection against icing is also provided by heating of the engine inlet lip

Question 18

How is ITT detected in the engine?

Answer 18

10 probes between the compressor and power turbines.

Question 19

What are the two different bleed valvles?

Answer 19

P2.5 (>80% Ng)

P3 (<80% Ng)

functions to prevent compressor stalls on start or in low power settings