Engine Differences
 

Hello to one and all lovely folk !

Time has come again, when contemplating certain things in life has left me in a dazzled state ;)

Okay, okay... to cut to the chase - what I require from all you brainy, intelligent turbine engine buffs is information on the specific differences between a Fixed Shaft Turbine vs the Free Power Turbine.
Pros and Cons of each would be terrific :cool:

...and in case you are wondering - NO, I haven't 'lost it ' psychologically ... just an enquiry and to settle THE GREAT DEBATE between my flatmate ( who flies Fixed Shaft turbines) and myself - a Free Power Turbine dude.

All your help/respones much appreciated - LONG LIVE THE FREE POWER TURBINE :D :D :D

Regards to all in advance.

Hot tip Hottie - you are on the better horse...........!

"specific differences"?

One is connected mechanically, one isn't. But I thought you'd know that?:D

perhaps this for starters
 

A free turbine engine can be designed so the power turbine(s) run at a different speed (RPM) to the compressor stages, thus allowing the engine designer to select the optimum design and speed for both sections of the engine to meet the particular requirement.

(higher propeller rotational speeds and noise level during ground operations?)

A fixed shaft system has longer shaft(s) creating more torsional loads and perhaps needing more bearings.

The starter/generator of a fixed shaft engine must turn over the dead weight and drag of the propeller so presumably is more robust, heavier, have a bigger current draw (perhaps requiring a longer recovery period for the battery before starting #2).

etc
regards

Absolutely no contest.

Fixed shaft, low profile, real simple and very economical.

Starting is not a problem if you know how to operate them.

Any turbine with a prop is good.
Any turbine without a prop is BETTER !!!

That's all you need to know.

Pistons are for cars and prop's are for boats...or so I was once informed :D

Looks like I fly an amphibious machine then :)

Very common Cathay type question that!... for anyone that is interested...

Sure there isnt an ulterior motive there Hottie?? ;)

Jeez I hate those Garrets uuugggghhhh give me some earplugs!

.. but just pray that the autofeather or NTS on the fixed turbine doesn't fail when the engine does ..........

Having flown many hours in 2 fixed shaft aircraft and 4 free turbine aircraft, their are only 2 major differences.

1. A fixed shaft has instant power when the leavers move forward.
2. A free turbine aircraft slows instantly when the leavers move back.

Other than these, they fly and operate the same way.

Hottie a free turbine has a lot of hot wind blows on the windmill thingy attached to the kepellor geer box.
The other ones geerbox is fixed to the hot windmill thingy in the hot part and is connected directly to the kepellor. None of this should be touched or altered by a pilot.Some times its not a bad idea to cover the EGT thingy when yer startin with a flat battery.
Hope this clears it up for you.
Your pal.