Yes you are right, Turboprop controls are different to a turbojet. There are two controls (levers) for each engine.t-rehman wrote: ↑Fri Nov 27, 2020 1:31 am Do we have any volunteer who can translate the report in layman's language?
The operation of turbo prop is not as simple as it seems. I guess its not throttle forward - more power, throttle backward - less power. The blade pitch angle is playing a very important role here
Would appreciate if somebody can assist in understanding the jargons involved (blade pitch / propeller speed etc). Thanks
First is called Condition Lever, It controls the prop RPM, feather control and on some designs a fuel cut-off position if there is no separate control for fuel cut off. For RPM there is usually a separate ground and flight idle detent. Beyond flight idle, pilot can select any RPM upto max RPM in flight. Usually for take off and landing, max rpm is selected and for cruise, a lower RPM can be set.
Condition lever also has a feather position, for manual feathering if required. PLease note that condition lever DOES NOT change the power of the engine. That is achieved through power lever, explained below.
Second control is called Power Lever. During flight pilot uses this to control the engine thrust for various phases of flight. Once condition lever has been positioned at max or cruise position (in flight or ground), movement of the power lever changes the pitch of the prop , lever forward, more pitch , more bite hence more power, lever back, flatter pitch less bite, less power.
Power lever also has Reverse Pitch position for thrust reverse during landing.
In one of innovative designs in TBM950, (a single engine 6 seater turboprop) a single lever has been used to achieve all three finctions, i.e fuel cut off, idle control and power.
Hope it makes sense