"Dan Truesdell" wrote in message

This is GE's UDF (for UnDucted Fan) project. Theory was that the high
efficiency blades would add up to better fuel consumption. The program
was never brought to market. The image you posted is one of the flying
testbeds (possible the only, although I think there might have been a
727 used first).

I never heard about a 727 UDF -- possible, but #2 engine would be a tough
one. I talked to a few folks involved after the project died - I think
around 89 or 90. They said it actually showed a lot of promise, good
efficiency over the jet for short range. But the word was that the
marketing results killed it. It just looked scary. Given a choice, focus
groups always shied away from "prop planes". They were considered old. I
used to run into that in commuter lines, too. People would get off a 20
year old Boeing, and board a brand new t-prop and crack jokes about the
props. A mind is a marvelous thing, wasted.

JG