Ultralight rotorcraft

On Fri, 1 Jul 2005 at 01:35:15 in message
, Larry Dighera
wrote:
On Fri, 01 Jul 2005 01:07:19 GMT, David CL Francis
wrote in
::


I don't believe the aircraft under discussion is an autogyro.

What is it then?

Here's how the inventor describes it:

http://www.airscooter.com/pages/airscooter_main.htm

Going back to the future of rotor craft design is the basic
concept of the AirScooter VTOL (Vertical Take Off and Landing)
vehicle by AirScooter Corporation of Henderson, Nevada. "The
original Sikorsky rotorcraft helicopter concept was based on a
coaxial design much like the AirScooter," says Woody Norris;
internationally recognized inventor and AirScooter Corporation
co-founder, "what we've done is package the coaxial design in a
modern light-weight craft that allows for intuitive control and
incredible maneuverability."

All that seems to tell you is that it has coaxial contra-rotating
rotors. So torque reaction should not be a problem unless the rotation
speed of the rotors can be different.

By eliminating the need and complexity of swashplates, collective
and cyclic control through a coaxial rotor design a number of
benefits beyond conventional helicopter designs are immediately
realized.

I see what you mean but if it has no collective or cyclic controls then
what is the control method? This seems to remain unclear.

First; enhanced, intuitive flight controls are achieved
by simple motorcycle-style handlebars and the absence of a tail
rotor. To gain altitude, simply throttle up like you would on a
motorcycle, turn left or right on the handlebars for craft
rotation and move the handlebar assembly as a joystick for
directional control (including reverse). No pedal controls are
necessary, which means someone without the use of their legs can
just as easily fly the AirScooter. Handlebar controls represent
the most distinguishable feature of the AirScooter. AirScooter's
patented design also provides an amazing level of stability while
in the air and during

None of the above gives any indication of what is being controlled by
the handlebars/stick controls. The controls indicate a 3 axis control
system plus throttle but it does not tell us how it works. Anyway what
is the advantage of handlebars over pedals?

Anybody purchased and tried the model?

More information is needed and my question still stands. Is it a
helicopter, an autogiro or is it something else instead?
--
David CL Francis

David CL Francis wrote:

What is it then?

It's a twin-rotor helicopter. The rotors have nested driveshafts and rotate in
opposite directions. That eliminates the need to change the angle of the rotor
as it goes around.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

On Sat, 2 Jul 2005 at 03:36:36 in message 8Znxe.794$vu5.439@trndny08,
George Patterson wrote:
David CL Francis wrote:
What is it then?

It's a twin-rotor helicopter. The rotors have nested driveshafts and
rotate in opposite directions. That eliminates the need to change the
angle of the rotor as it goes around.

But what is the control system George? Attempts at concentric
helicopters have been made before. But if there are no collective or
cyclic pitch controls then how is it controlled?
--
David CL Francis

David CL Francis opined

On Sat, 2 Jul 2005 at 03:36:36 in message 8Znxe.794$vu5.439@trndny08,
George Patterson wrote:
David CL Francis wrote:
What is it then?

It's a twin-rotor helicopter. The rotors have nested driveshafts and
rotate in opposite directions. That eliminates the need to change the
angle of the rotor as it goes around.

But what is the control system George? Attempts at concentric
helicopters have been made before. But if there are no collective or
cyclic pitch controls then how is it controlled?

THrottle instead of collective, weight shift instead of cyclic. Ghod knows
what you use instead of tail rotor collective.

-ash
Cthulhu in 2005!
Why wait for nature?

On Sun, 3 Jul 2005 at 12:57:46 in message
, Ash Wyllie wrote:
But what is the control system George? Attempts at concentric
helicopters have been made before. But if there are no collective or
cyclic pitch controls then how is it controlled?

THrottle instead of collective, weight shift instead of cyclic. Ghod knows
what you use instead of tail rotor collective.

Well autogiros used to have a jump mode, when they clutched the rotor to
make an initial vertical take-off. Their control system was one where a
single lever tilted the rotor both fore and aft and side to sided.
However that does not exactly fit with the 'advance the throttle' to
climb quote! Except you _do have_ to advance the throttle to climb in an
autogiro.

They don't need much of a tail rotor to control yaw rotation because of
the contra rotating rotors. An autogiro usually has a fin and rudder and
sometime stabilisers as well and relies on forward speed to control
rotation.

--
David CL Francis

Some still do have jump mode.

Bryan "The Monk" Chaisone

On 3 Jul 2005 12:57:46 -0500, "Ash Wyllie" wrote in
::

Ghod knows what you use instead of tail rotor collective.

Last Sunday's "60 Minutes" show contained a segment on this aircraft,
Moller's, and Carter's. From observing the AirScotter in flight, it
appears that there are two rudders mounted behind the pilot positioned
in downwash. These rudders seem to be longitudinally hinged at their
tops, so that they can deflect downwash air laterally to the side for
yaw control. Altitude is controlled with throttle, and the handlebars
tilt the rotor blades for directional control. At least that was what
I thought I saw.

As the AirScotter is intended to be flown at altitudes below 400' AGL,
perhaps there is adequate inertia in the rotor blades to safely set it
down in the event of an engine failure; just a guess.

Larry Dighera opined

On 3 Jul 2005 12:57:46 -0500, "Ash Wyllie" wrote in
::

Ghod knows what you use instead of tail rotor collective.

Last Sunday's "60 Minutes" show contained a segment on this aircraft,
Moller's, and Carter's. From observing the AirScotter in flight, it
appears that there are two rudders mounted behind the pilot positioned
in downwash. These rudders seem to be longitudinally hinged at their
tops, so that they can deflect downwash air laterally to the side for
yaw control. Altitude is controlled with throttle, and the handlebars
tilt the rotor blades for directional control. At least that was what
I thought I saw.

As the AirScotter is intended to be flown at altitudes below 400' AGL,
perhaps there is adequate inertia in the rotor blades to safely set it
down in the event of an engine failure; just a guess.

I find that unlikely... There isn't enough inertia in the rotor of a Bell 47
to a safe auto from 10', let alone 400' (witout a lot of forward airspeed).
ANd that is with a collective.


-ash
Cthulhu in 2005!
Why wait for nature?