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A comment on Nascar Driver Stuns to Qualify for Championship with GameCube Move. Parent comment

Re:Nascar Driver Stuns to Qualify for Championship with Game... by lisper on Monday October 31, 2022 @11:08PM (#33416459)
When I was in high school a local science museum had an annual paper airplane contest. One of the events was duration of flight. The launch platform was a second-story landing. One year I won with a simple piece of paper the size of a dollar bill that was bent into a S-shape profile so that it would twirl as it fell. It turns out this is actually a legitimate way to produce lift, and actual human-carrying aircraft have been built with wings that use this principle, but I didn't know that at the time, and neither did the competition organizers. They thought I was cheating, and so did I. So the next year they tried to change the rules in a way that would disqualify my design but they couldn't come up with a legitimate way to phrase such a rule, so in the end they decided on a very clever solution: all entries in the duration-of-flight event had to carry a penny as a payload.

So I built a very large version of the same design out of computer punch cards taped together, and won again. I'm still proud of that.

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Re:Nascar Driver Stuns to Qualify for Championship with Game... by thrtythreeforty on Tuesday November 01, 2022 @12:30AM (#33416927)
This is sort of similar to helicopter autorotation, isn't it?
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Re:Nascar Driver Stuns to Qualify for Championship with Game... by pclmulqdq on Tuesday November 01, 2022 @01:58AM (#33417513)
Yes, this is basically how you are supposed to crash-land a helicopter if the engine fails.
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Re:Nascar Driver Stuns to Qualify for Championship with Game... by K0balt on Tuesday November 01, 2022 @05:50AM (#33418989)
Actually in this case he’s using an airfoil spinning on a horizontal axis perpendicular to the direction of flight.

But yes, helicopters can be safely landed this way without power (not crash landed, but actually landed, though crashing is always an option lol)

Also, gyrocopters use the same principle for all phases of controlled flight, by simply using a traction engine to move the aircraft foreword, with a free spinning, unpowered, typically fixed pitch or no cyclic control rotor providing the lift.

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Re:Nascar Driver Stuns to Qualify for Championship with Game... by pclmulqdq on Tuesday November 01, 2022 @01:13PM (#33424117)
When I was trying to get a helicopter license (pre-pandemic), I did one of these as part of training (the instructor had me actually complete the landing... he was a little crazy) and I wouldn't exactly consider it a typical landing, but the helicopter and its occupants were indeed in working order.
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Re:Nascar Driver Stuns to Qualify for Championship with Game... by kqr on Tuesday November 01, 2022 @02:59AM (#33417902)
It depends on how you interpret the parent comment, but my guess is no. The autorotation you're speaking of happens in a plane roughly parallel to the ground. This is a very powerful and stable way for a wing to generate lift: https://www.av8n.com/how/htm/spins.html#sec-samara

There's another option, which is counter-rotation along an axis parallel to the ground, and orthogonal to the direction of travel. This mechanically induces circulation, which produces lift (by the same principle that a curveball produces sideways lift.) Here's more information on this funky phenomenon: https://www.av8n.com/how/htm/airfoils.html#sec-spinners

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Re:Nascar Driver Stuns to Qualify for Championship with Game... by lisper on Tuesday November 01, 2022 @04:09AM (#33418310)
It depends on what you consider "similar", but no, the rotation of the paper has nothing to do with the rotation of helicopter blades during autorotation. In that case, the blades act like ordinary wings and they do an ordinary glide, albeit in a circular direction because the blades are fixed at one end. What happens with the paper is different. The axis of rotation is horizontal rather than vertical.

However, there is a sort of rotation about a horizontal axis in an ordinary wing because a wing produces vortices, and this is a necessary part of the process of producing lift [1]. In heavy aircraft these vortices can be surprisingly powerful and long-lasting, to the point where they can cause smaller aircraft to lose control and even crash if they get caught in one [2].

That first reference has an excellent description of what was going on in my design [3].

[1] https://www.av8n.com/how/htm/airfoils.html#sec-circulation-v...

[2] https://en.wikipedia.org/wiki/Wake_turbulence

[3] https://www.av8n.com/how/htm/airfoils.html#sec-spinners

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Re:Nascar Driver Stuns to Qualify for Championship with Game... by thrtythreeforty on Tuesday November 01, 2022 @02:07PM (#33425003)
I see, thank you. Your initial description sounded more like a maple seed's wing. I did not know you could generate lift as described in your links.
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Re:Nascar Driver Stuns to Qualify for Championship with Game... by lisper on Tuesday November 01, 2022 @02:13PM (#33425088)
Neither did I :-) I only learned about it about 20 years after the fact.
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Re:Nascar Driver Stuns to Qualify for Championship with Game... by Shocka1 on Tuesday November 01, 2022 @10:00AM (#33421342)
You are basically the Smokey Yunick of paper airplanes:

https://web.archive.org/web/20060323051213/http://insiderrac...

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Re:Nascar Driver Stuns to Qualify for Championship with Game... by dugmartin on Tuesday November 01, 2022 @10:13AM (#33421499)
That reminds me of when I carefully built a "lightbulb drop" challenge container that looked like the moon lander in high school art. We were given two pieces of construction paper, two straws and two large rubber bands. I spent a week I think building and testing my design so that it would use the straws and rubber bands like springs and the paper like fins to ensure it landed in the right position and prevent the lightbulb from breaking.

Cue "demo day": my friend forgot about the project and took the straws and wrapped them around the bulb and then crinkled up the construction paper roughly and wrapped it around the straws and bulb and then took the rubber bands and secured the paper. I think he spent maybe a minute on it.

I think you maybe know how this ends. The teacher sneered at his design but then proceeded to drop it several times from the top of a ladder and the bulb never broke. He then took my design and dropped it upside down (springs pointing up) and the bulb shattered. I still think about that and laugh 30+ years later.

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