Simviation Forums

Hello Chums....

After some 10+ years of flying Carburettor/Fuel Injected Piston Prop engines, I have recently delved into the delights (or otherwise) of Turbine Prop engines.

Note: Turbine Prop Engines!..NOT Turbo-Prop, Piston Engines!!

My latest escapades involve the FS 2004 Default Beechcraft King Air 350, and I was wondering what was the difference (and reasons) between "Low Idle" and "High Idle" on the Fuel Levers?

"Power" is similar to "Throttle" on Piston Engines, and "Condition" is similar to "Prop Pitch: Coarse/Fine".
But apart from using the Fuel lever to "Cut off" (stop) the engine, I still can't find the effects/reasons of selecting High Idle and Low Idle?...;)...!
Is it similar to Rich/Weak mixture on a Carburettor Piston Engine?

Any advice?.... ;)...!

...anyway, whilst Googling for some help regarding this, this interesting article cropped-up regarding Turbine Prop Engines; Pratt and Whitney (PT6), and Garrett:...>>>>

http://home.earthlink.net/~x-plane/FAQ-History-710.html

Paul...G-BPLF... 8-)...!

Note: Turbine Prop Engines!..NOT Turbo-Prop, Piston Engines!!

What's the difference Paul? The King Air is a turboprop. http://en.wikipedia.org/wiki/Turboprop

Not sure what a turbo-prop piston engine is. Do you mean turbo-supercharged? [url]http://en.wikipedia.org/wiki/Turbocharger
[/url]

The low/high idle setting is a taxiing/flying deal. It's kind of like a sub-throttle. The power you'd want at "idle" on the ground, is quite a bit less than want you'd want whilst airborne.

The only real turbine experience I have, is some informal, right-seat time in a C90  (I still logged it), and that's how it was explained to me. And I spent an afternoon visiting with a Shorts-360 pilot in Indiana, while my Cardinal's landing gear were getting worked on.

The prop condition lever is about the same function. While it does indeed modulate the prop blades from fine to coarse, you don't really "choose" a pitch, so much as you choose an RPM and then the pitch modulates by power-setting and load to maintain that RPM setting.

It's a little more complicated for a turbine engine, as the power curve is very different.. AND, most turbine-engined planes allow for full feathering AND full Beta.

Note: Turbine Prop Engines!..NOT Turbo-Prop, Piston Engines!!

What's the difference Paul? The King Air is a turboprop. http://en.wikipedia.org/wiki/Turboprop

Not sure what a turbo-prop piston engine is. Do you mean turbo-supercharged? [url]http://en.wikipedia.org/wiki/Turbocharger
[/url]

Hello Doug... ...!

The King Air engine is fitted with a "Turbine Engine"...(ie Pratt and Whitney PT6).

A "Turbo-Prop engine" is an Piston Engine fitted with an exhaust driven Turbo-Charger (like a Car engine).

Turbo/Turbine always confuses lots of Folks...!

LOL...!

Paul....Turbine Engine: P&W and Garrett.... 8-)...!

Note: Turbine Prop Engines!..NOT Turbo-Prop, Piston Engines!!

What's the difference Paul? The King Air is a turboprop. http://en.wikipedia.org/wiki/Turboprop

Not sure what a turbo-prop piston engine is. Do you mean turbo-supercharged? [url]http://en.wikipedia.org/wiki/Turbocharger
[/url]

Hello Doug... ...!

The King Air engine is fitted with a "Turbine Engine"...(ie Pratt and Whitney PT6).

A "Turbo-Prop engine" is an Piston Engine fitted with an exhaust driven Turbo-Charger (like a Car engine).

Turbo/Turbine always confuses lots of Folks...!

LOL...!

Hi Paul. I think you're the one that's confused. Read my links.

Paul....Turbine Engine: P&W and Garrett.... 8-)...!

What you're describing is a turboprop. A gas-turbine engine driving a propeller.

The low/high idle setting is a taxiing/flying deal. It's kind of like a sub-throttle. The power you'd want at "idle" on the ground, is quite a bit less than want you'd want whilst airborne.

The only real turbine experience I have, is some informal, right-seat time in a C90  (I still logged it), and that's how it was explained to me. And I spent an afternoon visiting with a Shorts-360 pilot in Indiana, while my Cardinal's landing gear were getting worked on.

The prop condition lever is about the same function. While it does indeed modulate the prop blades from fine to coarse, you don't really "choose" a pitch, so much as you choose an RPM and then the pitch modulates by power-setting and load to maintain that RPM setting.

It's a little more complicated for a turbine engine, as the power curve is very different.. AND, most turbine-engined planes allow for full feathering AND full Beta.

Hello Brett...

Ta for the info.......!

I still try to compare my Turbine Engine controls to my Piston Engine controls... ...!

Getting there, slowly... ...!

What I do notice tho', is the delay in engine/air speed response to opening and closing the Power Lever....makes reducing air speed prior to landing somewhat different to a Piston Prop plane where the reduction in air speed is much more responsive/quicker......!

...and that screaming "Turbine" sound makes you think you are traveling much faster than your really are!... ....LOL...!

Paul...G-BPLF... 8-)...!

Note: Turbine Prop Engines!..NOT Turbo-Prop, Piston Engines!!

What's the difference Paul? The King Air is a turboprop. http://en.wikipedia.org/wiki/Turboprop

Not sure what a turbo-prop piston engine is. Do you mean turbo-supercharged? [url]http://en.wikipedia.org/wiki/Turbocharger
[/url]

Hello Doug... :)...!

The King Air engine is fitted with a "Turbine Engine"...(ie Pratt and Whitney PT6).

A "Turbo-Prop engine" is an Piston Engine fitted with an exhaust driven Turbo-Charger (like a Car engine).

Turbo/Turbine always confuses lots of Folks...!

LOL...!

Hi Paul. I think you're the one that's confused. Read my links. :P

Paul....Turbine Engine: P&W and Garrett.... 8-)...!

What you're describing is a turboprop. A gas-turbine engine driving a propeller.

Hello Doug...

I think the confusion arises when some Sim Aircraft designers/Flight Simmers, describe their Planes as being Turbo-Props, for example; the "Beech Baron TC", a Piston engine fitted with an add-on, exhaust driven, turbo-charger...!

Certainly not a Turbine Prop Engine!

Paul... :)...!

My 1931 Brooklands Riley 9 was fitted with a direct, crankshaft driven, Roots Supercharger...>>>

http://en.wikipedia.org/wiki/Roots_type_supercharger

Hello Doug...

I think the confusion arises when some Sim Aircraft designers/Flight Simmers, describe their Planes as being Turbo-Props, for example; the "Beech Baron TC", a Piston engine fitted with an add-on, exhaust driven, turbo-charger...!

Certainly not a Turbine Prop Engine!

Paul... ...!

I wouldn't know about that Paul. What I do know is that the King Air is a turboprop. http://en.wikipedia.org/wiki/Beechcraft_King_Air
I've never heard it described as a turbine prop engine.

What I do notice tho', is the delay in engine/air speed response to opening and closing the Power Lever....makes reducing air speed prior to landing somewhat different to a Piston Prop plane where the reduction in air speed is much more responsive/quicker......!

Ahh yes, the turbine lag. It's the biggest adjustment a pilot has to learn. It takes some time for the turbine to "spool up"; whereas

You might want too look at rick pipers HS .748, it has the same system, that the angle is limited on the ground for taxing and changed for take off, the FFstop, it is all very well explained in the manual.

You might want too look at rick pipers HS .748, it has the same system, that the angle is limited on the ground for taxing and changed for take off, the FFstop, it is all very well explained in the manual.

Blimey.... ...!

Installed the HS 748 Turbo/Turbine Prop....A bit of a handful!.... ... ...!

I think I will stick to the Beech King Air 350 for a while, its somewhat simpler to operate, and just about as speedy... ...!

Had a read of the Manual. Very useful... ...!

Cheers...!

Paul...G-BPLF... 8-)...!

Prop controls on most turboprops are only used for feathering, and switching to a low power "ground idle" mode as opposed to an "in flight mode. Normally, the whole poer/pitch relationship takes care of itself ,and you jest have to monitor RPM as being in limits

I allways looked at it this way A turbo prop is like you said a piston engine with a turbo charger in it, the exhaust ports for the turbo charger give it away. A turbo jet is a jet engine with a propeller. A good example a P3 ORION or the C130 8-)

I kinda veered off.. Let's clear this up..

A Turboprop is a propeller driven plane with a turbine engine (C-130, Caravan, KingAir, P-3, .. etc)

A Turbojet is a jet driven plane. In the early days, turbojets were the only type of jet (707).. later planes were/are sometimes called turbofans (747) (high by-pass turbojets)..

A turbo-charged piston plane is just that..a

You might want too look at rick pipers HS .748, it has the same system, that the angle is limited on the ground for taxing and changed for take off, the FFstop, it is all very well explained in the manual.

Blimey.... ...!

Installed the HS 748 Turbo/Turbine Prop....A bit of a handful!.... ... ...!

I think I will stick to the Beech King Air 350 for a while, its somewhat simpler to operate, and just about as speedy... ...!

Had a read of the Manual. Very useful... ...!

Cheers...!

Paul...G-BPLF... 8-)...!

You'll grow too love her, she can challenge most small landing strips if done with care!