V-22 Prop Configuration, 3-vs-4 blades

Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?

"Don McIntyre" wrote:

Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?

Well, you can bet your arse that all configs were considered,
number of blades, length pitch width of blades, RPM range etc
etc...That a/c is a real departure from the conventional and must
have been a real headache to design and proove. I hope that they
now have a safe aircraft, they sure had their teething problems
didn't they?...
--

-Gord.
(use gordon in email)

"Don McIntyre" wrote in message
oups.com...
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?

I would suspect it is a compromise due to the amount of force that has to be
applied through comparatively small components and the strength of the
materials out of which those components can be built.
--
Andrew Chaplin
SIT MIHI GLADIUS SICUT SANCTO MARTINO
(If you're going to e-mail me, you'll have to get "yourfinger." out.)

Don McIntyre wrote:
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?


I would think folding 3 blades would be easier and lighter than
folding 4.

Dan, U.S. Air Force, retired

Dan wrote:

Don McIntyre wrote:
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?


I would think folding 3 blades would be easier and lighter than
folding 4.

Dan, U.S. Air Force, retired

?? Folding ??
--

-Gord.
(use gordon in email)

"Gord Beaman" wrote in message
...
Dan wrote:

Don McIntyre wrote:
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?


I would think folding 3 blades would be easier and lighter than
folding 4.

Dan, U.S. Air Force, retired

?? Folding ??
--

-Gord.
(use gordon in email)

http://www.paravion.com/products/407...e_fold_kit.htm

Keith

"Keith W" wrote:


"Gord Beaman" wrote in message
.. .
Dan wrote:

Don McIntyre wrote:
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?


I would think folding 3 blades would be easier and lighter than
folding 4.

Dan, U.S. Air Force, retired

?? Folding ??
--

-Gord.
(use gordon in email)

http://www.paravion.com/products/407...e_fold_kit.htm

Keith

Thanks Keith...I thought that Dan was referring to the V-22...I
don't think that it 'has' folding blades does it?...
--

-Gord.
(use gordon in email)

Gord Beaman wrote:
"Keith W" wrote:

"Gord Beaman" wrote in message
...
Dan wrote:

Don McIntyre wrote:
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?

I would think folding 3 blades would be easier and lighter than
folding 4.

Dan, U.S. Air Force, retired
?? Folding ??
--

-Gord.
(use gordon in email)
http://www.paravion.com/products/407...e_fold_kit.htm

Keith

Thanks Keith...I thought that Dan was referring to the V-22...I
don't think that it 'has' folding blades does it?...

Yep, it sure does. If you could ever describe an aircraft as folding up
like a pretzel, the V-22 is it:

http://www.globalsecurity.org/milita...d-wing-seq.htm

"Don McIntyre" wrote in message
oups.com...
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?

More blades = less efficiency.

Shorter blades = less efficiency in vertical flight.

They probably couldn't have absorbed the performance loss from both
increasing the number of blades and reducing blade length.

KB

Kyle Boatright wrote:
"Don McIntyre" wrote in message
oups.com...
Why did they settle on the 3-blade configuration? Wouldn't a 4-bladed
system allow for a smaller footprint on the ground (or ship)? Or is
there too much thrust loss involved?

More blades = less efficiency.

Shorter blades = less efficiency in vertical flight.

They probably couldn't have absorbed the performance loss from both
increasing the number of blades and reducing blade length.

KB
How does more blades equal less efficiency? If that is true why do all
current Helicopters use 4-5 blades instead of two like the legacy
systems of the Huey and Cobra? Why do all modern turbo-props have more
then two blades? Somthing sounds off here. Guesses are like.... Anyone
actually involved in the engineering of the V-22 or at least privy to
some of the original evaluation documentation?
Reed