Engines

Question 1

The engine is divided into four modules:

Answer 1

cold section, hot section, power turbine section, and accessory section

Question 2

Cold section

Answer 2

(a) Cleans
(b) Directs
(c) Then compress the air
(Suck/Squeeze)

Question 3

Hot Section

Answer 3

Provides the necessary area for mixing of fuel and air for combustion

Question 4

Power Turbine section

Answer 4

Extracts energy from hot expanding gases and converts it to mechanical energy (shaft horsepower)

Question 5

Accessory Section

Answer 5

provides for engine-driven accessories and engine starting.

accessory section module is driven by the radial driveshaft

Question 6

ATS

Answer 6

1. Rotates the compressor until self-sustaining (52% Ng)
2. PRSOV regulates air from IPAS to ATS (Pressure regulating shutoff valve)

Question 7

Engine Fuel Boost Pump

Answer 7

Engine-driven, non-self-priming suction and pressure pump

Suction ensures that fuel supply system is under negative pressure, reducing danger of fire in case of fuel system damage

Question 8

Common Hydromechanical Unit (CHMU)

Answer 8

The CHMU provides metered fuel to the combustor to control the gas generator (NG) speed.

Provides fuel pumping, metering, flow computation, pressurization, shutoff, Ng control, compressor variable stator vane actuation, anti-icing and start bleed valve actuation

Ng overspeed protection (mechanical) at 110±2% Ng, results in flameout

Question 9

ODV

Answer 9

i. Provides fuel to the 12 fuel injectors

ii. Np overspeed protection (electrical) at 118.1±1% Np from EDECU

Question 10

Ignition System

Answer 10

Each engine has an ignition exciter unit with two igniter plugs. The exciter unit re-ceives power from its engine alternator.

Question 11

3 windings of the alternator

Answer 11

(1) The engine-driven alternator supplies 115 Vac for the engine electrical system.
three windings providing power for:
(a) Engine ignition
(b) Ng speed indication
(c) EDECU

Question 12

2 overspeed protections

Answer 12

NG mechanical
NP digital

Question 13

Enhanced Digital Electronic Control Unit (EDECU)

Answer 13

The EDECU controls the engine and transmits information to the crew.

MTRA
OVERSPEED PROTECTION
Transient droop improvement
TGT LIMITING
TQ MATCHING
HOT START PREVENTION
FAULT CODES

Question 14

Maximum Torque Rate Attenuator (MTRA)

Answer 14

Reduces the risk of exceeding DE torque limits during uncompensated maneuvers.

These are any maneuvers where pedal or cyclic inputs are made but no collective control input occurs.

Question 15

Engine Chip Detector

Answer 15

The chip detector attracts metal particles that may be present in the Engine Oil System.

The chip detector consists of an outer shell with internal magnet, electrical connector, removable screen and has no fuzz suppression (burning-off) capabilities.

Question 16

Yellow wire

Answer 16

Yellow harness supplies power and control system trim signals

Question 17

Blue Wires

Answer 17

Blue harness passes all overspeed and torque signals.

Question 18

Green Wires

Answer 18

Green harness conducts engine condition monitoring (crewstation instrumentation)

Question 19

The engine alternator has three windings providing power for:

Answer 19

(a) Engine ignition
(b) Ng speed indication
(c) EDECU

Question 20

Engine Chop Control

Answer 20

The guarded Chop (CHOP) button on the flight grip of the collective provides a means to immediately and simultaneously reduce both engines electronically to idle.
After pressing you must reduce power levers to idle or else the engines will go back to fly.

Question 21

PAS

Answer 21

Power available spindle: The PAS is mechanically connected to the pilot’s power levers

converts push-pull motion at the POWER levers to rotary motion at the CHMU input shaft.

Question 22

LDS

Answer 22

Converts push-pull motion at the collective lever to rotary motion at the CHMU input shaft.

Load demand spindle is connected to a bellcrank attached to the collective servo.

Question 23

Black cable

Answer 23

For starting

Question 24

Air Turbine Starter:

Answer 24

1. Rotates the compressor until self-sustaining (52% Ng)
2. PRSOV regulates air from IPAS to ATS

Question 25

Power Available Spindle

Answer 25

provides power lever input (on CHMU)

Question 26

Load Demand Spindle

Answer 26

provides collective load demand input (on CHMU)