15.17 Turbo-shaft Engines Flashcards
What is a turbo shaft engine used for?
It operates anything other than an aeroplane propeller
Where would you find an application of a turbo shaft engine in a modern aircraft?
The APU
What is a Twin Pac?
A combination of two turboshaft engines with a combining gearbox
What is a freewheel unit?
It connects twin pack engines together when both engines are running at the same RPM.
If one engine loses power or is shut down, the respective freewheel unit disengages. Both freewheel units disengage in the event of an auto rotation so that the rotor doesn’t drive the engine.
How does a turbo shaft inlet protect itself from ingesting FOD?
Using a Particle Separator
How does a particle separator work?
It uses centrifugal force to separate the particles and scavenge them overboard
What is the purpose of a drive system on a turboshaft engine?
It transfers the power from the engine to a main rotor gearbox (or an electrical generator for APU)
What is the purpose of the universal joint on a turbo-shaft engine?
It ensures alignment of the shaft between the engine and the MRGB and absorbs low amplitude oscillations during flight
Where are the hydraulic pumps connected to on a helicopter turboshaft engine?
The main rotor gearbox - ensuring power even when loss of engine
How does a helicopter gain electrical power?
It has starter generators mounted on the accessory gearbox or sometimes a electrical generator located on the MRGB
What is the advantage of auto-rotation when a turboshaft engine fails?
It drives a transmission which can supply emergency hydraulic power including a rescue winch
