Bell Textron D-314 tiltrotor designs.

During the 1970's, Bell came up with a variety of Tiltrotor concepts,
including several gunship models. Does anyone know where a good place
to start looking for conceptual art or planned specifications would
be?

Also, isn't a tilt-rotor considerably less effecient than a
helicopter in vertical flight?

Charles Gray wrote:
Also, isn't a tilt-rotor considerably less effecient than a
helicopter in vertical flight?

Yes

You dont get something for nothing. Tiltrotors have extreamly high disk
loading which makes hover performance very poor.

John Roncallo

Charles Gray wrote:

Also, isn't a tilt-rotor considerably less effecient than a

helicopter in vertical flight?

Yes

You dont get something for nothing. Tiltrotors have extreamly high disk

loading which makes hover performance very poor.

John Roncallo

But then...what do you consider Vertical "Flight"? A V-22 Osprey or any
other tilt rotor ie. Bell or Kawasaki weren't developed for Vertical
"Flight". They were developed to get to their approximate destinations at
fixed wing speeds. In commercial applications this would allow for them to
fly in a commercial traffic arrival pattern (as toward a major airport and
then "break out" to transition to a heliport. In military applications they
could get to a destination at fixed wing speeds and then transition in and
out of a "LZ" pick up or deploy personnel or cargo. Comparing them to
helicopters is apples and oranges.

But then...what do you consider Vertical "Flight"? A V-22 Osprey or any
other tilt rotor ie. Bell or Kawasaki weren't developed for Vertical
"Flight". They were developed to get to their approximate destinations at
fixed wing speeds. In commercial applications this would allow for them to
fly in a commercial traffic arrival pattern (as toward a major airport and
then "break out" to transition to a heliport. In military applications they
could get to a destination at fixed wing speeds and then transition in and
out of a "LZ" pick up or deploy personnel or cargo. Comparing them to
helicopters is apples and oranges.



Point taken, John. OTOH, aren't you talking about some transition to vertical
flight when they leave standard fixed wing patterns to land at a helipad or
some out of the way LZ that a fixed wing could never hope to arrive at in one
piece? Both of those scenarios will involve a transition to hover for landing
and a vertical lift off to hover before the climb out and acceleration to fixed
wing mode which is not unlike what helicopters do under normal circumstances
anyway, with the exception of the fixed wing mode part, that is. :-)

Fly Safe,
Steve R.

On 12 Dec 2003 14:25:59 GMT, (Rhodesst) wrote:

But then...what do you consider Vertical "Flight"? A V-22 Osprey or any
other tilt rotor ie. Bell or Kawasaki weren't developed for Vertical
"Flight". They were developed to get to their approximate destinations at
fixed wing speeds. In commercial applications this would allow for them to
fly in a commercial traffic arrival pattern (as toward a major airport and
then "break out" to transition to a heliport. In military applications they
could get to a destination at fixed wing speeds and then transition in and
out of a "LZ" pick up or deploy personnel or cargo. Comparing them to
helicopters is apples and oranges.



Point taken, John. OTOH, aren't you talking about some transition to vertical
flight when they leave standard fixed wing patterns to land at a helipad or
some out of the way LZ that a fixed wing could never hope to arrive at in one
piece? Both of those scenarios will involve a transition to hover for landing
and a vertical lift off to hover before the climb out and acceleration to fixed
wing mode which is not unlike what helicopters do under normal circumstances
anyway, with the exception of the fixed wing mode part, that is. :-)

Fly Safe,
Steve R.


The conceptual art for the gunship designs had them hovering to
launch their ordanance, and one conception had the rotors interfering
with the underwing gunpods in horizontal flight.
So, I wonder if the intended use of the design was to use the
horizontal flight as a dash and transit mode, and then quickly
transition to Vertical hover to fire thier ordanance before dashing
off somewhere else.

Charles Gray wrote in
:

The conceptual art for the gunship designs had them
hovering to
launch their ordanance, and one conception had the rotors
interfering with the underwing gunpods in horizontal
flight.
So, I wonder if the intended use of the design was to
use the
horizontal flight as a dash and transit mode, and then
quickly transition to Vertical hover to fire thier
ordanance before dashing off somewhere else.


The rotors wouldn't interfere with the guns in horizontal
flight. The ability to fire through the propellor was invented
in WWI. It's trivial to do it now.

--
Regards,

Stan

Rhodesst wrote:
But then...what do you consider Vertical "Flight"? A V-22 Osprey or any
other tilt rotor ie. Bell or Kawasaki weren't developed for Vertical
"Flight". They were developed to get to their approximate destinations at
fixed wing speeds. In commercial applications this would allow for them to
fly in a commercial traffic arrival pattern (as toward a major airport and
then "break out" to transition to a heliport.

What stops an S-76 from doing this?

John Roncallo

In military applications they
could get to a destination at fixed wing speeds and then transition in and
out of a "LZ" pick up or deploy personnel or cargo. Comparing them to
helicopters is apples and oranges.




Point taken, John. OTOH, aren't you talking about some transition to vertical
flight when they leave standard fixed wing patterns to land at a helipad or
some out of the way LZ that a fixed wing could never hope to arrive at in one
piece? Both of those scenarios will involve a transition to hover for landing
and a vertical lift off to hover before the climb out and acceleration to fixed
wing mode which is not unlike what helicopters do under normal circumstances
anyway, with the exception of the fixed wing mode part, that is. :-)

Fly Safe,
Steve R.

What stops an S-76 or any other helicopter from doing this is that their
SLOW speed doesn't allow them to STACK UP with 747's et.al. in an approach
pattern to ANY major airport. In other words they can't keep up with the
big boys, so they can't play.

Bob

John Roncallo wrote in
m:


What stops an S-76 from doing this?

Nothing. But flying an approach to an airport and then breaking
off is very inefficient. Better to fly the approach directly to
the helipad. With differential GPS coming on, it's going to be
easy to do.

--
Regards,

Stan