mistarose

I am taking a systems class at school right now, we're learning how the free-turbine, reverse-flow turboprop engine's work. It is basically a Kingair B-200 Systems Class which is supposed to give us a idea of what to expect from a 135 ground school.

Anyways... Just curious if anyone has found a online resource on a visual explanation of the specific turboprop engine that has a free-turbine and is reverse flow.

I am having difficulties grasping the whole concept, just have a training manual with black and white pictures here that I am trying to interpret and understand.

Thanks in advance!

ctd57

What are you having trouble with understanding. Let me know, maybe I can clear it up for you.
I assume you are talking about the PT-6.

HSLD

Here's an animation:

http://www.pratt-whitney.com/how.htm click: "TurboPropTurboProp Engines"

mistarose

Thanks for the link for the animation. Yes I am talking about the PT-6 - which differs from that animation in that (in the PT-6) the air does several 180 degree turns before it is introduced to the fuel and ignited. Also in the PT-6 there are actually two shafts (split shaft) so you can spin the prop freely on the ground without moving the engine.

I am just trying to put all the pieces together and see how everything interacts. The more variety of explanations and visuals I see, the easier it is to piece it all together. thanks!

I understand that it is a broad question, when I think of something specific about the engine I will be sure to ask.

Pilotpip

Use Google for "PT-6 Diagram" or something to that effect. I had a bunch of stuff for a report back in college. Those things have been around for like 40 years so there is lots of info out there.

Laxrox43

Hey Mistarose...what classroom text are you using? I might have a book or two that I could suggest...

Lemme know boss...
Lax

mistarose

I have been googling for awhile now, haven't found much - but I never typed in "diagram" so I'll give that a shot.

I actually only have a "turboprop training manual" put together by my school, its all black and white. Like I said, just looking for as many different explanations and diagrams as possible to study with. Thanks for the replies.

FlyerJosh

Here are two cutaway photos of an older PT-6. Might help:

http://www.myaviation.net/search/pho...hp?id=00664589
http://www.myaviation.net/search/pho...hp?id=00664588

FlyerJosh

Here's an even better diagram:

http://ffden-2.phys.uaf.edu/212_fall...shman/3-36.jpg

Here's some text (along with a few other graphics), from the P&W website.

http://www.pwc.ca/en/3_0/3_0_1/3_0_1_2_1.asp

FlyerJosh

One thing that is worth noting (and can be a bit confusing from these various diagrams), is that the cutaways make everything seem "2D" when it comes to the engine. Instead think of the engine as a "pipeline" with various twists and turns (inside of each other). Also remember that these diagrams show the engine as if it's hanging in space.

When mounted on the airplane, the air intake (which is visible at the bottom of the nacelle behind the prop), directs air down the bottom of the engine, where it is "fed" (by the initial separator vane) up to the intake screen. Excess air (that the intake can't handle) is sent down along the bottom of the engine to the engine oil cooler and other accessory components.

If you can't get a good idea of how it all fits together, let me know... I have a lot of good diagrams (including non-cutaway ones and separate component "puzzle" diagrams) that I can scan and send to you about the PT6A-65B engines. (The -65B enginesare mounted on the B1900... don't know about the particular model king air you're studying.. I think they are very similar, but not quite exactly the same.)

~Josh