No.1 on my Christmas list

[JuST Peter]

http://www.businessinsider.com.au/hoverbike-is-like-a-flying-motorcycle-2014-8

[Biggles]

That looks like fun.
I wonder how well it auto-rotates, though?  Auto-rots depend to a large extent on rotor momentum, and those rotors lack that much of that.

[Shiney]

Looks cool

[Diesel]

That looks like fun.
I wonder how well it auto-rotates, though?  Auto-rots depend to a large extent on rotor momentum, and those rotors lack that much of that.

One would think one the rotors would 'counter' rotate comparative to the other, but would the inertial gyroscopic offset work in this configuration Biggles?

[Biggles]

The steering is accomplished either by blade pitch or velocity change on one side and and climb/descend by front/rear changes.
My concern is what happens when the engine (or motor in the case of the electric prototype) quits.
In a heli as we know them, the pilot pitches forward using the momentum of the rotor, and the rate of descent is balanced against the blade angle (pitch).  The airflow keeps the rotating wing revolving like on a gyrocopter.  The instant the heli is positioned to flare the pilot dumps the collective and the sudden pitch change arrests the descent at the expense of the rotational force.  You have only one shot at that- do it too high and you hit the ground hard, do it too late and you hit the ground hard.

[Tipsy]

  py
they could put a crank handle gizmo on it maybe    chute
 

Tipsy

[Brock]

The instant the heli is positioned to flare the pilot dumps the collective

I must correct you here Biggles, you got it backwards.

On entering Autorotation, the collective is dumped giving a fine pitch allowing the rotor energy to be maintained. The cyclic is used to maintain directional control. When flaring the collective is pulled up, to increase lift (to stop the fall) using the stored energy. As the sink rate nears zero, the collective is slowly lowered and a nice gentle (or not so gentle) running landing is made. Or thats what happened in the Hueys I was in ( and maintained for 3 years) Some landings during training caused the skids to spread some what, made loading into aHerc to get it back to Fairburn awkward that did.

Running take offs were fun as well, rotor at 6,600 revs, cyclic forward until chopper starts to drag forward on the skids ( easier in the Blackhawks, as they have wheels). A bit more cyclic, and inch of left pedal, reach 20 knots and claw into the sky..

[Biggles]

Thanks for sorting the terminology out.
I think you'd agree those light rotors won't have much stored energy to convert to lift in the flare, assuming they are able to offer much by way of a steep "gliding" approach rather than a near-vertical fall.

[Brock]

I dread to think what would happen if one rotor seized, fell off or whatever, or two even!!!!

Massive drop or pitch in an uncontrolable manner would be deadly. 200 ft and 80 ks and you tilt any which way, and you are going to hit hard.

I dont think the lift is generated by pitch change, but by rotor speed, so I think an auto would be out of the question

 

[Diesel]

It may employ similar stability technology to some fighter jets whom would be inherently unstable, and unflyable without constant computer sensor input.

[Biggles]

"whom" Diesel?   

I can't let that clanger go through to the keeper!!

So these unstable contraptions have personality as well?

I know, picky picky.   

[JuST Peter]

It wouldn't surprise me if he's been letting his spell checker loose again 

[Diesel]

Quote from: Biggles on 01-09-2014, 21:55:42

"whom" Diesel?   

I can't let that clanger go through to the keeper!!

So these unstable contraptions have personality as well?
 

Coming from the bloke who calls his ST "Ruby"   


Guess it's anonymous now that we're both doing it!