ORIGINAL: w8ye
A 6-bladed prop would be very inefficient
Jim,
It ain't necessarily so (© George & Ira Gershwin - Porgy and Bess 1935)...
Watch this [link=http://www.youtube.com/watch?v=yyHySgD6l08]Antonov An-70 video[/link].
The front prop has 8 blades and the counter-rotating rear prop has 6.
It seems effective, at over 82% efficiency.
Also see the [link=http://www.airbusmilitary.com/press.html]Airbus A400M[/link]. A single prop with 8 blades absorbing 11,000 HP. Scroll down to the photos.