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

Reed Judd-Dyer wrote

How does more blades equal less efficiency?

Those of us that flew rubber band powered contest model
aircraft way back ('40s-'50s) KNOW that the most efficient
propellor has only ONE blade...and a counterweight on the
other side. :-)

Bob Moore

"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

Jim Carriere wrote:

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:


Absolutely amazing!...Sorry Dan, I'm still shaking my head in
amazement...quite an aircraft!.
--

-Gord.
(use gordon in email)

Bob Moore wrote:

Reed Judd-Dyer wrote

How does more blades equal less efficiency?

Those of us that flew rubber band powered contest model
aircraft way back ('40s-'50s) KNOW that the most efficient
propellor has only ONE blade...and a counterweight on the
other side. :-)

Bob Moore

A Helo with one blade would have to be the most uncomfortable ride,
until after a minute or so, when it had shook itself to pieces.

Jeremy Thomson

wrote in news:1143609590.585290.233720
@u72g2000cwu.googlegroups.com:


Bob Moore wrote:

Reed Judd-Dyer wrote

How does more blades equal less efficiency?

Those of us that flew rubber band powered contest model
aircraft way back ('40s-'50s) KNOW that the most efficient
propellor has only ONE blade...and a counterweight on the
other side. :-)

Bob Moore

A Helo with one blade would have to be the most uncomfortable ride,
until after a minute or so, when it had shook itself to pieces.

Jeremy Thomson

He did say with "a counterweight on the other side", so balance is not an
issue. This works better on larger, slower turning props, though. I'd hate
to try it on a fast spinning model airplane prop.

Dave in San Diego

In article .com,
wrote:

Bob Moore wrote:

Reed Judd-Dyer wrote

How does more blades equal less efficiency?

Those of us that flew rubber band powered contest model
aircraft way back ('40s-'50s) KNOW that the most efficient
propellor has only ONE blade...and a counterweight on the
other side. :-)

Bob Moore

A Helo with one blade would have to be the most uncomfortable ride,
until after a minute or so, when it had shook itself to pieces.

quite a bit less than a minute...

The single-blade prop with counterweight actually worked pretty well in
testing.

Best configuration for the V-22, you ask? In combat, a heap of burning
wreckage or in peace time... a cancelled project piece of scrap metal.
Transitional a/c are inherently dangerous no matter what, and if the
primitive Iraqis can down an Apache how much more vunerable is the
tilt-rotor Osprey... or rather "Easy Prey"?

Imagine an Osprey loaded with troops as it transitions to take off or
land in Iraq. One RPG or heavy MG fire to the rotor system and the US
will be scraping the remains of its troops out of the dirt and sand
with shovels.

Why doesn't someone cancel this flying cemetery already? Like the
F/A-22 seems the number "22" in US inventory= disaster. The Craptor and
Easy Prey need the axe. Cancelling the Craptor will save money while
cancelling Easy Prey will save lives.

Rob

Rob,
I don't understand your point. The same could apply to any "lift"
vehicle. Helos, C-130s, C-17s, H-60s, you name it. The advances in
design, the increase in speed and range over conventional helos seem to
me to make the V-22 a large advance of helos. We've become so
conditioned to our "safe" world that we tend to forget that new
technology does take tme to mature and develop. Some have forgotten
that the F4, F-14 and in particular the Century series jets that many
of we aviation fans have come to know and love had their fair shre of
crashes and developmental disasters before the matured into useable
RELATIVELY safe systems.
Cancelling the V-22 and F-22 leaves us with, what? When the F-35
comes along will you want to cancel that as well? I want our Armed
forces to have the best. What can beat the F-22? Oh, wait, maybe we
should buy Su-30s! I don't think so.

Rob Arndt wrote:
Best configuration for the V-22, you ask? In combat, a heap of burning
wreckage or in peace time... a cancelled project piece of scrap metal.
Transitional a/c are inherently dangerous no matter what, and if the
primitive Iraqis can down an Apache how much more vunerable is the
tilt-rotor Osprey... or rather "Easy Prey"?

Imagine an Osprey loaded with troops as it transitions to take off or
land in Iraq. One RPG or heavy MG fire to the rotor system and the US
will be scraping the remains of its troops out of the dirt and sand
with shovels.

Why doesn't someone cancel this flying cemetery already? Like the
F/A-22 seems the number "22" in US inventory= disaster. The Craptor and
Easy Prey need the axe. Cancelling the Craptor will save money while
cancelling Easy Prey will save lives.

Rob

This is from the fool who thinks Japan needs ICBMs, nuclear powered
aircraft carriers and nuclear powered submarines to protect itself from
China and North Korea. Then again he also believes a 34 pound weapon is
an excellent E&E choice for downed air crews, the Earth is hollow,
there's a secret still operational Nazi underground U-boat base in
Antarctica.....etc.

Dan, U.S. Air Force, retired