Bell Textron D-314 tiltrotor designs.

[Charles Gray]

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?

[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

[Bob]

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.

[Rhodesst]

>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.

[Charles Gray]

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.

[John Roncallo]

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.

[Bob]

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]

Bob wrote:

> 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
>
>

I have flown into JFK and BOS in a fixed wing Piper Archer. It is not a
helicopter but it is a lot slower than an S-76.

J. Roncallo

[JIM105]

>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
>
Not hardly. On numerous occasions in the -76 I'm asked to slow during the
approach because I'm gaining on the airliner in front of me. One of the nicest
things you can hear from ATC. On the other hand, I can't take the 76 500 miles
without refueling and getting above much of the weather like the tilt rotor
will be able to do (someday).

Jim

[Helimech]

Does the S76 have that long of range? I didn't think it was that high, or
is that with aux tanks? JC
"JIM105" > wrote in message
...
> >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
> >
> Not hardly. On numerous occasions in the -76 I'm asked to slow during
the
> approach because I'm gaining on the airliner in front of me. One of the
nicest
> things you can hear from ATC. On the other hand, I can't take the 76 500
miles
> without refueling and getting above much of the weather like the tilt
rotor
> will be able to do (someday).
>
> Jim
>

[Stan Gosnell]

"Helimech" > wrote in
news:yHRDb.570333$Tr4.1545717@attbi_s03:

> Does the S76 have that long of range? I didn't think it
> was that high, or is that with aux tanks? JC

He said he can't go that far. A standard S76 can go about 350NM
without refueling, with 30 minute reserve, topped off. And I
agree with Jim, I can go as fast as the airliners on approach -
they have to slow way down for an approach, I don't. Top speed
is just slightly higher for a 777, though. :-D

--
Regards,

Stan

[Stan Gosnell]

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

[Stan Gosnell]

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

[Charles Gray]

On 17 Dec 2003 05:35:42 GMT, Stan Gosnell <me@work> wrote:

>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.

Well the gun was an underslung turret much like the cobra-- the
underwing hard points appeared to be either TOWS, or Hellfire
missiles-- since the design was a mid-1970's, early 1980's, they might
have been artist conceptions of hellfires, or one of the other ATGM's
that never actually made it to service.
If they're not wire guided, I could see dropping for a short
distance before the moter engaged, thus clearing the roters, but for
anything like unguilded 2.75 rockets or wire guided missiles, it
wouldn't be so easy.

[George Vranek]

"JIM105" > wrote in message
...
> Not hardly. On numerous occasions in the -76 I'm asked to slow during
the
> approach because I'm gaining on the airliner in front of me. One of the
nicest
> things you can hear from ATC. On the other hand, I can't take the 76 500
miles
> without refueling and getting above much of the weather like the tilt
rotor
> will be able to do (someday).
>
> Jim

It's hardly to believe, that the tilt rotor will be able (someday) to fly so
fast and so far as a conventional turboprop and lift in hovering so much as
a conventional helicopter with the same installed power, because the tilt
rotor (tilt wing) has not and could never have optimal rotors for hovering
and optimal props for cruising. But the disk rotor helicopter shown on the
www.vranek.ch/diskrotor.htm will be able (someday) to cruise as fast as a
Lear Jet above all of the weather and lift in hoverig so much as a
conventional helicopter with the same installed power.

George

[John Roncallo]

George Vranek wrote:
> "JIM105" > wrote in message
> ...
>
>>Not hardly. On numerous occasions in the -76 I'm asked to slow during
>
> the
>
>>approach because I'm gaining on the airliner in front of me. One of the
>
> nicest
>
>>things you can hear from ATC. On the other hand, I can't take the 76 500
>
> miles
>
>>without refueling and getting above much of the weather like the tilt
>
> rotor
>
>>will be able to do (someday).
>>
>>Jim
>
>
> It's hardly to believe, that the tilt rotor will be able (someday) to fly so
> fast and so far as a conventional turboprop and lift in hovering so much as
> a conventional helicopter with the same installed power, because the tilt
> rotor (tilt wing) has not and could never have optimal rotors for hovering
> and optimal props for cruising. But the disk rotor helicopter shown on the
> www.vranek.ch/diskrotor.htm will be able (someday) to cruise as fast as a
> Lear Jet above all of the weather and lift in hoverig so much as a
> conventional helicopter with the same installed power.
>
> George
>
>

OK George

I said your concept had about as much merit as a tilt rotor in previous
posts. But now you are trying to stretch it a bit.

J. Roncallo

[George Vranek]

"John Roncallo" > wrote in message
. com...
> George Vranek wrote:
> > It's hardly to believe, that the tilt rotor will be able (someday) to
fly so
> > fast and so far as a conventional turboprop and lift in hovering so much
as
> > a conventional helicopter with the same installed power, because the
tilt
> > rotor (tilt wing) has not and could never have optimal rotors for
hovering
> > and optimal props for cruising. But the disk rotor helicopter shown on
the
> > www.vranek.ch/diskrotor.htm will be able (someday) to cruise as fast as
a
> > Lear Jet above all of the weather and lift in hoverig so much as a
> > conventional helicopter with the same installed power.
> >
> > George
> >

> OK George
>
> I said your concept had about as much merit as a tilt rotor in previous
> posts. But now you are trying to stretch it a bit.
>
> J. Roncallo


Hallo John

I am pleased, that you still remember me and the disk rotor helicopter.
Years ago I saw the Bell XV-15 flying at the Paris Airshow and my opinion
was, that the pilot transports a basket of rough eggs. When I was a farmer
boy, I often had to transport a basket of rough eggs to the city with the
bicycle of my mom. Therefore I know, what it means.... Now, a row of years
later and development costs of billion $$, the V22 does not fly better.
Therefore I mean, that the disk rotor concept has much more merit as a
tiltrotor and I am only trying to publish this fact.

George

[John Roncallo]

George Vranek wrote:

> "John Roncallo" > wrote in message
> . com...
>
>>George Vranek wrote:
>>
>>>It's hardly to believe, that the tilt rotor will be able (someday) to
>
> fly so
>
>>>fast and so far as a conventional turboprop and lift in hovering so much
>
> as
>
>>>a conventional helicopter with the same installed power, because the
>
> tilt
>
>>>rotor (tilt wing) has not and could never have optimal rotors for
>
> hovering
>
>>>and optimal props for cruising. But the disk rotor helicopter shown on
>
> the
>
>>>www.vranek.ch/diskrotor.htm will be able (someday) to cruise as fast as
>
> a
>
>>>Lear Jet above all of the weather and lift in hoverig so much as a
>>>conventional helicopter with the same installed power.
>>>
>>>George
>>>
>
>
>>OK George
>>
>>I said your concept had about as much merit as a tilt rotor in previous
>>posts. But now you are trying to stretch it a bit.
>>
>>J. Roncallo
>
>
>
> Hallo John
>
> I am pleased, that you still remember me and the disk rotor helicopter.
> Years ago I saw the Bell XV-15 flying at the Paris Airshow and my opinion
> was, that the pilot transports a basket of rough eggs. When I was a farmer
> boy, I often had to transport a basket of rough eggs to the city with the
> bicycle of my mom. Therefore I know, what it means.... Now, a row of years
> later and development costs of billion $$, the V22 does not fly better.
> Therefore I mean, that the disk rotor concept has much more merit as a
> tiltrotor and I am only trying to publish this fact.
>
> George
>
>

I'm not challenging whether the disk rotor will out perform the tilt
rotor. But your message states you will get the same performance with
the disk rotor as you will with an airplane in airplane mode or as much
performance as a helicopter in hover mode. This I find to be pushing the
limits of insulting our intelligence.

John Roncallo

[George Vranek]

"John Roncallo" > wrote in message
. com...
> I'm not challenging whether the disk rotor will out perform the tilt
> rotor. But your message states you will get the same performance with
> the disk rotor as you will with an airplane in airplane mode or as much
> performance as a helicopter in hover mode. This I find to be pushing the
> limits of insulting our intelligence.
>
> John Roncallo
>

I am sorry John, but my mother speach is not english and therefore you could
get the impression, that I am pushing the limits of insulting your
intelligence. I only want to explaine why the disk rotor is better than the
tilt rotor. You know, the conventional rotor is good for hovering only and
to fly fast with it is an aerodynamic crime, which is punished immediately
by vibrations, noise, low efficiency... The disk in the disk rotor improves
the rotor efficiency in hovering and compensates so its weight penalty. In
the cruisig, the rotor blades are retracted in the disk and the disk acts
than as a fixed wing, which is well suitable for fast flying similar to a
delta wing. Please have a look at www.vranek.ch/diskrotor.htm for more
details.

George