Propfans ?
 

I remember a few years ago seeing pictures in Flight International (and others), of what I think were called prop fan, which looked kind of like broad propellers located at the back of what looked like jet engines. I remember in particular a picture of what I think was a DC9. I believe at the time, the big plus that was claimed were significant cost savings.

What happened to this development path - is it continuing or has it died, and if so, why ?

I have just found a Russian example

http://www.rob.clubkawasaki.com/jas4159.jpg

Seem to remember that Boeing produced a proposal with twin rear propfans. Might be wrong here, but 7J7 rings a bell. I think it was similar to 757 in size, and the props used highly profiled blades, like those on the new C130J. Benefits were economy and low noise (I think) but the project died a death.

I think this was the most "Famous" example.

http://www.airliners.net/open.file/166061/M/

A book I have says that "After the price of crude oil peaked at around $34 per barrel in the mid-1980's, it fell to below $10 before the end of that decade, with the result that the expense of further research could no longer be justified."

hence
http://www.airliners.net/open.file/141998/M/

That's the one I was thinking of.

So, killed by oil price . . . .

Folks,

Am I right in thinking Boeing had such an idea also, or was I getting them mixed up with MDD?