Allison 250 turbine engine cutaway.

[freak1289]

Here are a few videos of a C18 gas turbine engine I have recently completed sectioning and setting up to display.
It is now being used as a pilot training aid by Becker Helicopters on the Sunshine Coast Qld Australia.
The model was a genuine complete engine when I received it from the customer almost 2 years ago.
Over 1500 hours of labour were put into it, the results proving what an invaluable tool for explaining to student pilots and maybe a few engineers how a turbine engine works.

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[Flying Bull]

Thumbs up!
Well done!

[Sanus]

Awesome work! :ok:

[Peter3127]

Ok, I admit that I am an occasional nerd. And I may have a few Mech. Eng. degrees ... but ..... that is EXTREMELY cool.

I would love to see the hot section glow red during the start in the peaks ... maybe it was there but I could not see.

Sensational job. :D :8 :D

[MOSTAFA]

Outstanding work, I would have loved to have seen this about 25 years ago when I did a conversion onto the A109A I think they were C20s but it looks pretty much as I remember it.

[cattletruck]

This is art :ok:.

[Chris P Bacon]

Can't help but think this is an accident waiting to happen.
Either under power or just when turned by hand, I can see a digit going missing at some stage from an inquisitive oxygen stealer poking into one of the rotors.

I have seen an accident happen with our display M250 engine which has covers. Someone found a small opening which if he bent his finger the correct way, he could turn the compressor rotor. He forgot he needed to get his finger out of the way and was not quick enough.

Maybe some perspex covers or safety guards would not go amiss.

[krypton_john]

That really is cool.

[Woodbine john]

Great learning tool. Would have saved me a lot of classroom time ! You should put it on you-tube if not already there.

[firebird_uk]

They say a picture says a thousand words, well this takes it one step further!

Excellent work.

[tartare]

Freak - that's fantastic - well done.
Surprised to see how small the compressors and stators are at the front.
In fact the whole thing is pretty small - and yet they put out such power.
Great educational tool.

[hillberg]

That the greatest cut awat I've ever seen, #1 dander is if someone gets too close & gets shreaded by the compressor (Them blades are sharp!)

[Tony Mabelis]

In my day.............the early days, Allison 250's would regularly section themselves!!
Tony

[fly911]

freak1289, that is amazing. Congratulations!

[BlenderPilot]

Beautiful! Felicidades from Mexico!!

[Rotorhead84]

What do all the colors represent? It seems straightforward for those who know how it works, but for those that don't, a "key" of sorts would be helpful. Very cool.

[fly911]

The compressor on the left forces air (through the blue lined tubes in the foreground) to the yellow combustion section on the right (where the air and fuel mixture ignite). Expanding hot gasses (shown in orange) are forced toward the left through two sets of turbine wheels. (Small blades in the wheels forces them to spin as the gasses race toward the white exhaust). One set of turbine wheels turns the (Green) gearbox which powers the helicopter rotors. (The other set turns the compressor).

[riff_raff]

I'm one of those engineers that works on the design of turboshaft engines and helicopter drivetrains, but the ability of these turboshaft engines to operate at the temperature, speed, power output, and reliability levels they do still amazes me.

[Bravo73]

The compressor on the left forces air (through the blue lined tubes in the foreground) to the yellow combustion section on the right (where the air and fuel mixture ignite). Expanding hot gasses (shown in orange) are forced toward the left through two sets of turbine wheels. (Small blades in the wheels forces them to spin as the gasses race toward the white exhaust). One set of turbine wheels turns the (Green) gearbox which powers the helicopter rotors. (The other set turns the compressor).

I also interpreted the colours as blue for cool, yellow for hot and white for exhaust.

To the OP: that is a remarkable piece of work. If only they could be manufactured for a sensible price, I'm sure that you would have a willing worldwide market.

[Gemini Twin]

It's even more remarkable when you consider in the case of the C20/C20B that the compressor consumes 600 shp when the out put shaft is putting out
useful power of 400/420 shp.

[carsickpuppy]

Great effort, a practical piece of art, I have just the spot picked out for one in my den!

[MOSTAFA]

I agree agree with GT those incredible tiny engines never let me down in 1300hrs of A109A time - memory might be wrong and many engines have gone in between since those days but I think the 10 second Q limit on both engines was 145%? Obviously pre FADEC. I just remember it being very generous.

[riff_raff]

The workmanship and visual/audio effects used in the cutaway model are fantastic.

One suggestion I would make is a slight change to the coloring scheme used to convey the relative metal surface temperatures in the gas flow circuit. The color scale (cold to hot) of blue-red-orange-yellow-white is appropriate, since that is approximately the color change progression that takes place in metals as they heat up. Since this is an educational tool for mechanics & pilots, what you want to convey visually is the relative temperature of the metal surfaces in the various sections of the gas flow circuit. With regards to safety and reliability of these metal components, temperature is a major factor.

It looks like the color is created by painting the surface of the parts, so it would seem fairly easy to produce various shades of each color. I would suggest using the following color scheme to provide a more accurate representation of the temperature gradients: First, the compressor stages should progressively change from blue to dull red, as this would represent the increase in temperature from one compressor stage to the next. The gas temperature at the discharge of the final compressor stage on this particular engine is probably in excess of 500degF, which is not really "cool". Second, the combustor color should progressively change from orange to yellow, and finally to white at the turbine inlet nozzle. The turbine inlet nozzle is where metal surface temperatures are highest. Lastly, the color of the turbine stages should progressively change back from white to yellow to orange, since the gas temperature drops as energy is extracted by each turbine stage.

I apologize if my suggestions sound like nitpicking. My only intent is to just help make an already excellent educational tool a little bit better.

Regards,
riff_raff