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Strange picture... they claim it to be a MD-81... but I'v never seen engines like that... looks like some sort of propellors on the far end of the engine...

Airliners.net picture

It is an 81(I think); those are experimental propfan engines that I've seen before. More info here:

http://www.aerospaceweb.org/question/pr ... 0067.shtml

Yup.. that's the one... interesting read... thanks Rottydaddy!

You do know that there are loads of comments further down which explain it....

We had this discussion a year or so ago. It did the rounds of the major airshows in the late 80s or early 90s...

As the three letters on the shroud allude to, .....it's an Un Ducted Fan............simple innit ?  ::)

Interesting concept, always neat to see innovative ideas..

I posted this in the Photos forum some time ago.



Taken with my old SureShot Zoom at the Farnborough Air Show. I believe it was static only & I never saw it in the air. I also saw a twin very much like the one in that Anet photo at the same show. I forget the year but could probably find out.

That one on the Ilyushin isn't a UDF, but the prototype for the An-70 engine (which is an improved NK-12). 13 fan blades in total on two shafts, 8 on the front prop and 5 on the back.

That one on the Ilyushin isn't a UDF, but the prototype for the An-70 engine (which is an improved NK-12). 13 fan blades in total on two shafts, 8 on the front prop and 5 on the back.

I think that was the conclusion we came to last time Doug posted that shot...

Here's a question: what became of this? Seemed like a good idea...

More economical small turbofans I suppose...

Here's a question: what became of this? Seemed like a good idea...

From what I picked up on was the safety concerns that whet with it. As it stands now, a duct engine seems safer because of its contained status. If a bird fly into a ductengine it simply get chopped up and spit out the back. Although there are accounts of birds hitting turboprops and becoming deadly projectiles.

Also, I am not sure, but I am pretty sure turbofans run at a must higher RPM than turboprops do. This engine is not really a turboprop, but a turbofan, not inside a duct.

Also, here in America we all know how airlines operate. Dont change a thing untill it is a matter of life and death. We all know arlines could pay for better equipment that would be more efficiant, but then again there are airlines that would just assume to fly whatever and charge you more.

Edit: Spelling

From what I picked up on was the safety concerns that whet with it. As it stands now, a duct engine seems safer because of its contained status. If a bird fly into a ductengine it simply get chopped up and spit out the back. Although there are accounts of birds hitting turboprops and becoming deadly projectiles.

Good point.

Also, I am not sure, but I am pretty sure turbofans run at a must higher RPM than turboprops do. This engine is not really a turboprop, but a turbofan, not inside a duct.

I could be wrong but I think the turbofans are quieter.

So he picked up a couple o' ultralights on the way... Big deal.  ;D