From: "Ted White" <twhite8 at cox.net>
To: "WSFA members" <WSFAlist at WSFA.org>
Subject: [WSFA] Re: Alternative reality v SF
Date: Thu, 28 Apr 2005 20:43:53 -0400
Reply-To: WSFA members <WSFAlist at WSFA.org>

----- Original Message -----
From: "Mike B." <omni at omniphile.com>
To: "WSFA members" <WSFAlist at WSFA.org>
Sent: Thursday, April 28, 2005 1:34 PM
Subject: [WSFA] Re: Alternative reality v SF

[..]
>
> As for planes with vertically mounted propellers, check out the Osprey.
> Takes off that way, then rotates the wings to aim the propellers forward
> for high speed flight.  You can't go fast with them vertical for the same
> reason that helicopters can't go fast:  the retreating and advancing
blades
> see different relative air flow velocities.  As you increase vehicle
speed
> eventually one blade will go supersonic while the one on the other side
of
> the "disk" is well below that, and the turbulence caused results in
flutter
> and blade failure, and blades don't usually like to go through the sonic
> barrier twice on every revolution anyway.  The "X-wing" design is another
> way to have both vertical takeoff and high speed level flight...basically
> you stop the helicopter blades once you are up and moving, and lock them
in
> a "X" shape so they act as fixed wings.  Don't know if they've actually
> built one of these yet or not.

Sounds like an old autogyro, although I believe its unpowered overhead
blades freewheeled.

--Ted White