

Andreas’ Personal Flying Suit (“Monocopter”) Project - xd
http://www.technologie-entwicklung.de/Gasturbines/Monocopter/body_monocopter.html

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jberryman
That is the most terrifying device I've seen in a while.

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Isamu
In case it is unclear, this approach is a ducted fan (driven by a gas turbine)
with vectored thrust nozzles. Very clever.

<http://en.wikipedia.org/wiki/Ducted_fan>

<http://en.wikipedia.org/wiki/Thrust_vectoring>

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tricky
IMHO this is an amazing project so there's that, but I don't understand the
flying suit in general. I would much rather fly in something that had a little
more structure to it and was more aerodynamically stable (e.g. a flying car)

Is anyone building a quadricopter that'll hold one person and fit in a 2 car
garage? I bet a lot of those would sell.

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burgerbrain
Quadricopter seem like a perfect candidate for personal air-vehicles. The
maneuverability rocks and the problem of computer control seems to be pretty
well understood. You could design a control system that anyone who's ever
played a video-game could master, the only real danger would be people doing
stupid things with them on purpose.

I haven't seen any examples larger than models though, do they not scale
trivially?

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lisper
Nothing scales trivially in the material world. The fundamental problem is
that as you scale, the strength of the structure increases as N^2 but the mass
increases as N^3.

> the only real danger would be people doing stupid things with them on
> purpose

Not even close. The quadricopter design is very non-robust in the presence of
a failed engine. That alone is probably a show-stopper for ever having one of
these as a passenger vehicle.

They do make wicked cool spy drones though.

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burgerbrain
They used to have man-sized quadrotors in the early 20th century. My
understanding is they went out of style because the material tech wasn't up to
stuff yet and there were control issues.

Also, is there a reason these couldn't auto-gyro? The mechanics of how that
works has always been a bit fuzzy for me.

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gvb
Q: Auto-gyro? A: Theoretically, yes. Practically, maybe.

Auto-gyroing would require pitch control of the blades. The toy quadcopters
control by differential thrust and torque. For attitude, they control the
thrust of the different motors to get a vectored thrust effect. For
orientation, the pairs of motors are spinning in opposite directions, so if
you spin a pair faster and a pair slower, the torque imbalance between the CW
and CCW spinning motors will spin the quadrotor body.

<http://en.wikipedia.org/wiki/Quadrotor>

Autorotation in a helicopter is done by setting the blade pitch negative so
that the rotor is driven by the air wooshing up through the rotor. When you
are close to the ground, you pull collective, trading the energy stored in the
spinning of the rotor blades for vertical thrust to slow your descent. If you
do it right, you land gently with a much slower rotor speed. If you do it
wrong, you fall the last five feet. :-O

(Auto-gyro works like a helicopter auto-rotation. I suspect auto-gyros
typically don't have as much blade pitch control as a helicopter. As I
understand it, it is much safer to land an auto-gyro with forward velocity and
a roll-out rather than vertically like a helicopter.)

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lisper
You would only need to auto-gyro in the event of fuel starvation or multiple
engine failure. That's not the hard part. The hard part is recovering from a
single engine failure. Now you have an unbalanced torque. If you don't notice
the problem and do something about it VERY fast then you will flip over. It
might be possible to develop a control system that can use the engine opposite
the failed one for attitude control while slowing the descent (or maybe even
maintaining altitude) with the other two still-balanced engines, but that is
one gnarly control problem.

Twin engine airplanes have this problem too but it's much less severe. Adverse
roll is a second-order effect in an airplane, it's a first-order effect in a
quad. An airplane has the tail tending to stabilize it. Despite all that,
losing an engine on takeoff in a twin engine aircraft is often catastrophic.
In a quad, I'd wager good money (though not my entire life savings) that it's
unrecoverable. But if you're going to put human passengers in it you have to
plan for that because it will happen sooner or later.

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burgerbrain
I can't quite figure out how using that _wouldn't_ roast you alive. 20 minutes
with a jet turbine on your back? Ouch!

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mostly_harmless
well, for one thing, i dont believe it is a _jet_ turbine. It appears that the
thrust is solely produced by a giant propeller.

The gas generator that runs the big fan is probably ventilated well enough not
to burn the pilot.

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burgerbrain
The article talks about it getting up to 300C. Regardless of how it works that
is a little concerning.

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buro9
I'd be more concerned about landing it. There's no cage around the pilot and
it must weigh quite a bit, if for whatever reason you lost thrust for a moment
during a descent you'd crush your lower body as you fell to the ground and the
machine strapped to your back fell too.

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camiller
Or even the straps of the harness restricting circulation to the pilots legs
leaving them numb at landing. Ever try to walk with your foot "asleep".

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JoeAltmaier
Now to find the pilot brave enough to fly the thing.

