Twistair - open frame from AAT

[PTKay]

I think it might be a surprise for some of you, but Avuiation Artur Trendak
presented yeasterday a new open frame tandem called Twistair.

It is based on a trike, but the rotor, rotor blades, rotor control is taken
from the new Zen2 cabin machine.

Read more here:

http://www.rotaryforum.com/forum/showthread.php?t=38484

 

[Joe Pires]

Well I like the little Pod thingy...but that apparent thrustline, and the obstructed view not so much.

 

[PTKay]

Well I like the little Pod thingy...but that apparent thrustline, and the obstructed view not so much.

The thrust line is one thing, but huge horizontal stabilizer on long arm
centred in the prop wash is another.

I think, this machine will be rock steady.

And the view... many (if not most) trikes have such frame.
It's just question of getting used to it.

I think trike pilots are potential customers for this machine.
The suffer very much not being able to fly by wind or turbulence.
Will appreciate familiar frame and feeling, with the possibility
of flying in extreme conditions (in trike terms).

 

[GA Rotor Guy]

Just curious; Why is the mast spliced in the middle? Is this for vibrations, or so the aircraft can be partially dis-assembled and put in a smaller trailer or through the average garage door?

 

[Abid]

Hi Paul: Looks like Artur decided to try Sergey Zozulya's Antares trike as a base for this gyroplane. He even left the back seat a bit higher as done in tandem trikes to improve visibility to the front for back seat co-pilot, same as DTA gyro did following their trike pedigree. It would be interesting to know what their testing revealed in terms of stability. I had thrust lines on our trike designs a little bit higher than neutral on purpose. Trikes don't have a horizontal stab and yet are very stable within their operating limitation in pitch both in static and dynamic sense due to wing's planform and airfoil design. Rotors do not provide enough to do that by themselves I think but allow for a tail which is easy to design and size to get similar results.
The mast is spliced because in a trike that is where you would pull out one of the AN-5 or M8 bolt secured with a quickly undone nut and pin (castle nut or wing nut) and fold the mast down to the front and put the triangulated A-frame (control frame) of the wing on the ground and literally remove the wing off the trike carriage. The front tube (called nose strut) also has quick pip pins that allow it to release above the fairings to allow this. In a gyro, you could use this tube instead of the A-frame to set and sypport the weight of the rotor on the ground to remove it off the frame in relative ease.
I do notice that they continue to do use a rotor without any pre-cone angle and their plates have no taper to allow proper bending upwards load spread. Though depending on material properties, it may be fine to have no pre-cone angle for those blades but tapering the plates so outward end is slimmer than root would be a good idea. I think AutoGyro learned this the hard way after finding cracks in their rotors.

 

[PTKay]

Just curious; Why is the mast spliced in the middle? Is this for vibrations,...

To avoid vibrations the rotor head is fixed with elastomer elements.

... or so the aircraft can be partially dis-assembled and put in a smaller trailer or through the average garage door?

The split is for easier disassembly.
If ordered as a kit, it packs into nice small box.

 

[PTKay]

Hi Paul: Looks like Artur decided to try Sergey Zozulya's Antares trike as a base for this gyroplane.

Yes, they cooperate. Sergey cooperates since long time with Kompol and Alek,
who manufactures the composite parts for Antares, but also the cabins for Zen1 and Zen2.
Now Sergey works also together with AAT.

It would be interesting to know what their testing revealed in terms of stability.
I had thrust lines on our trike designs a little bit higher than neutral on purpose.
Trikes don't have a horizontal stab....

The stability seems to be very good. They have placed a huge
horizontal stabilizer centred in the prop wash,
also the vertical fin is very big, both on long arm.

I do notice that they continue to do use a rotor without any pre-cone angle and their plates have no taper to allow proper bending upwards load spread. Though depending on material properties, it may be fine to have no pre-cone angle for those blades but tapering the plates so outward end is slimmer than root would be a good idea.

Stay tuned, there are also changes regarding the blades under way.
All in due time.

 

[GA Rotor Guy]

To avoid vibrations the rotor head is fixed with elastomer elements.

The split is for easier disassembly.
If ordered as a kit, it packs into nice small box.

THX!

I figured the isolation parts at the cheek plates...Good engineering! It was the split in the mast I was curious about.

 

[WHY]

This is going to bear close watching, again, it would seem progress comes out of europe .

Tony

 

[PTKay]

THX!

I figured the isolation parts at the cheek plates...Good engineering! It was the split in the mast I was curious about.

I think Fara explained in his post, where it comes from.

...
The mast is spliced because in a trike that is where you would pull out one of the AN-5 or M8 bolt secured with a quickly undone nut and pin (castle nut or wing nut) and fold the mast down to the front and put the triangulated A-frame (control frame) of the wing on the ground and literally remove the wing off the trike carriage. The front tube (called nose strut) also has quick pip pins that allow it to release above the fairings to allow this. In a gyro, you could use this tube instead of the A-frame to set and support the weight of the rotor on the ground to remove it off the frame in relative ease.
.....

I think, they will be considering such solution in the future.
The rotor control cables and the prerotator cable are flexible,
so a folding mast is quite easy to design.

It will then fit into standard garage.

 

[GA Rotor Guy]

I think Fara explained in his post, where it comes from.



I think, they will be considering such solution in the future.
The rotor control cables and the prerotator cable are flexible,
so a folding mast is quite easy to design.

It will then fit into standard garage.

THX PT, this explains much on the specific airframe.

There is one question I have: What about the vibs a rotorhead produces? There is a long controversy about NO holes in the mast (other than the cluster plates and cheek plates)...

I am in the middle of a build, am considering the idea of a folding mast (really would like to transport the gyro in a closed trailer for a variety of reasons). Other than the SportCopter (?) I have not seen much on folding masts. If you have any more information on this folding mast, I am quite interested!

THX!

 

[PTKay]

There is one question I have: What about the vibs a rotorhead produces?

As mentioned above, the vibrations are isolated from the mast
already on rotor head mounting with elastomers.

There is a long controversy about NO holes in the mast (other than the cluster plates and cheek plates)...

The construction of the Twsiter frame is different than most of the other gyroplanes,
it has the tube connecting it to the front of the cabin, so the mast must not carry
itself and alone high longitudinal forces. It just carries the load vertically.
In this case the holes are not so critical, the loads are much smaller.
Also the flexing mast on other gyroplanes has to carry the vibrations,
not the case here by the Twister.

 

[GA Rotor Guy]

As mentioned above, the vibrations are isolated from the mast
already on rotor head mounting with elastomers.



The construction of the Twsiter frame is different than most of the other gyroplanes,
it has the tube connecting it to the front of the cabin, so the mast must not carry
itself and alone high longitudinal forces. It just carries the load vertically.
In this case the holes are not so critical, the loads are much smaller.
Also the flexing mast on other gyroplanes has to carry the vibrations,
not the case here by the Twister.

THX! I am working with a Dominator frame, I do not think the forward tube will work. Will need to think over the 'donuts' between the mast and cheek plates, however that is a definite possibility.

THX for your input, if you think of anything else I would appreciate hearing it... THX again!

 

[Abid]

If it helps you can take a look at how we did the folding mast and front nose strut with a hinged unique design to make things easier on the last trike (Revo).

Lowering & Raising the Reflex wing on a REVO - YouTube

Recently Larry designed a dolly to make trailering the machine easier. No reason something like that cannot be done for the gyroplane also

Trike Dolly - YouTube

Hope this gives you some ideas

 

[GA Rotor Guy]

THX for the video's, yes they give me some ideas.

The issue to deal with is the vibrations and torsional loads a rotor wing (and especially a gyro) produce.

When I work out how to distribute the vibrations and torsional loads... the actual splitting and folding part will be easy.

THX again for the videos!

 

[PTKay]

If it helps you can take a look at how we did the folding mast and front nose strut with a hinged unique design to make things easier on the last trike (Revo).

...
Recently Larry designed a dolly to make trailering the machine easier. No reason something like that cannot be done for the gyroplane also

...

Being able to trailer a gyro in a closed, low trailer, as well as storing
it in a standard car garage is an important sales argument, no doubt.

It is high on the "to do" list since some time afaIk.

 

[scottessex]

Any more news on this gyro? Flight reports?

 

[Trendak&Son]

The certification process is under way.
Check this thread:

http://www.rotaryforum.com/forum/showthread.php?t=39946

Twistair was designed and will be certified for 560kg MTOW.

We hope to have it ready for Sun'n'Fun.

 

[PTKay]

Why an open two-seater should be certified for 560kg?

I understand, that the empty weight is way below 240kg,
so a useful load of 320kg is high, even for US standard.

Even with two 120kg (250lb) people there is still
80kg room for fuel (over 100l).