Human Powered Paper Airplane

gilgsn writes: "The Raven is a honeycomb paper, foam and graphite-fibre tape, human powered airplane designed to beat the current record held by MIT's Daedalus . The plane is also powered by a 16MHz Motorola 68332. The technical specifications of the onboard computer are pretty interesting. Unfortunately, as reported on Ananova, the Raven recently crashed a mere 100 feet after taking off, causing some damage to its fragile structure. Maybe they could upgrade to a Pentium and convinced Lance Armstrong to give it a try..."

Comments

"Human Powered Paper Airplane" == stupid title

[J.D. Hogg]

Err... when I folded that A4 sheet and threw it in the amphitheater at University, it sure seemed like a human powered paper airplane to me.

So, maybe the article is about a full-size airplane made of paper that is powered by a human being who also happens to be onboard ?

Re:"Human Powered Paper Airplane" == stupid title

[skyhawker]

Uh -- what you threw was a glider , not an airplane .

Re:A 16 MHz Proc?

[grub]

Re:A 16 MHz Proc?
they made it to the moon on far, far less.

Re:A 16 MHz Proc?

[grub]

Now, it's like saying, "let's go buy a 16 MHz proc... cause we can."
No, it's like saying "Let's use a CPU that will run on minimal power yet provide the processing power needed to control the aircraft."
Seriously, running a Pentium with the necessary chipset support, etc etc would need two pilots: one for the plane, one to power the computer.

Pentium? Are you nuts?

[x136]

Maybe they could upgrade to a Pentium

Uh, hello? This plane is made out of paper! Paper is flammable!

To recap: Paper Airplane + Pentium = Flaming Paper Airplane.

Given two equally equipped airplanes, it's kinda common sense that the one that isn't on fire will fly longer and farther. :)

No need to upgrade

[Space Cow]

As one of the control engineers who worked on this project, I can tell you there is no need to upgrade to a Pentium. The customized Tattletale system we were using had more than enough power.

The problems that I saw with this project had less to do with the control system and more to do with the airframe. The airframe was damaged a number of times and was extremely fragile. Damage probably occured during every flight test.

For those who are interested, I worked with the RAVEN team 2 years ago. I was resposible for getting an ultrasonic altitude sensor (primary) and a barometric altitude sensor (backup) to co-operate. The idea was that if the ultrasonic device failed the barometric would take over. The reason the barometric device wasn't the primary sensor was because of drift due to weather changes. Accuracy was important because the pilot was not a pilot, but rather an engine. The control system was in charge of maintaining altitude and heading.

Re:No need to upgrade

[Reality Master 101]

The reason the barometric device wasn't the primary sensor was because of drift due to weather changes.

Hey! Speaking of this, something I've always wondered...

I used to have a really cool Casio watch that had a built-in pressure sensor that told altitude and water-depth. One thing that I never understood was how you can tell altitude from a barometer. Wouldn't the weather changing make it completely inaccurate? I would imagine that air pressure changes fairly dramatically depending on the weather. How can it ever be remotely accurate? Or are weather-related pressure changes actually pretty minor as a percentage of average air pressure?

Re:No need to upgrade

[Captain Nitpick]

One thing that I never understood was how you can tell altitude from a barometer. Wouldn't the weather changing make it completely inaccurate? I would imagine that air pressure changes fairly dramatically depending on the weather. How can it ever be remotely accurate? Or are weather-related pressure changes actually pretty minor as a percentage of average air pressure?

A quick google search turns up a little information that answers your questions. Changes in weather do cause large fluctuations in what a barometric altimeter reads (>100 feet). Pilots relying on barometric altimeters must regularly recalibrate against readings on the ground.

Project shutting down?

[uchian]

It seems relevant that this link should be noted. Seems like the project's run out of funding?

Hey, this is local!

[Raetsel]

Paine Field is about 3 miles away from my house, if that. It's right across the 'street' from the Boeing 747/767 assembly plant -- you know, the "world's largest building"? (Largest, I suppose, in that it covers more land than any other building -- it's not particularly tall.)

I saw a news bit recently (last night?) about the crash... looked like one of those 'impending doom' situations, where you know things are going badly, and there's nothing you can do to stop it. Unwieldy looking landing gear, but necessary for the size of the prop the fellow is turning. I'm amazed there was as little damage -- it looked worse.

Here are some links from local news:

• Human-powered plane crashes on first flight
• Test flight for the human-powered Raven
• (includes post-crash picture)
• 'Raven' debuts at Museum of Flight (includes pre-crash picture)

Doesn't look like the pilot has much for visibility. It's one of the most recumbant positions I've seen for human-powered flight. When they were pulling him out, it looked like he's almost strapped to the underside of the spar!

Incidentally, the Boeing hangar (the 747 assembly building) is where some of the human-powered helicopter (!!!) tests have been conducted. It's the only indoor place large enough, and the tests have to be indoors because they need absolutely calm air.

Re:Hey, this is local!

[Space Cow]

"Doesn't look like the pilot has much for visibility. It's one of the most recumbant positions I've seen for human-powered flight. When they were pulling him out, it looked like he's almost strapped to the underside of the spar!"

The pilot doesn't need much visibility because he is just pedalling for all he is worth. The "engine" is an endurance cyclist and the "pilot" most of the time is the control system.

What's needed

[DeadBugs]

I found in my aerospace testing that adding a paper clip to the front of the airframe adds a great deal of stability.

Pilot vs. Engine

[Raetsel]

Paul MacCready had the Gossamer Condor and then the Gossamer Albatross -- two famous aircraft, to be sure.

A group at MIT built the Light Eagle and Daedalus.

In both cases, the pilot was in as complete control of the craft as I can imagine; providing both power and control input. Daedalus had a... problem... I believe it was a gust of wind that put it in the surf off Santorini beach. Perhaps, if the pilot had not been so exhausted from being the engine as well, that might not have happened. Good argument for flight controls that don't get tired.

Then there are people like me (an occasional sailplane pilot, more seldom than I'd like), who would rather not have something else be in control of a craft that is so vulnerable to the whims of the wind.

You mentioned the pilot "most of the time" is the electronics. How much control does the human engine actually have? (Just curious...) Granted, it'd be rather nice to have the 'highway in the sky' that NASA and Paul Moller keep crowing about...

It's rather ironic, actually, that this testing is happening on Boeing's home turf. The attitudes of Boeing vs. Airbus with regard to computer control used to be 180 apart: Boeing's computer systems would default to what the human pilot believed was necessary, while Airbus had a system that limited what the pilot was able to do. In effect, Airbus' computer design had final authority. I believe this changed after the A3xx airshow crash (when the pilot tried to apply power and ended up in the trees anyway), but I haven't heard anything about this for several years.

I hope more enlightened attitudes have prevailed.

Re:A 16 MHz Proc?

[Detritus]

One of the advantages of older processors is their lack of cache. This is important if deterministic timing is a requirement. The main engine controllers on the Space Shuttle use redundant pairs of 8 MHz Motorola 68000 processors.

First you get some feathers...

[thumbtack]

then some wax, but just don't fly to close to the sun....

Seriously, Paper? seems a little over the top. You're totally screwed if it gets wet, your insurance will be outragous, and there's alway the wife or girlfriend might clean out the hanger and through away all of that "old cardboard" setting around. And lets not forget, that turbulence that springs up at the worst possible moment..

Multiple pilots?

[Jeremi]

Hey guys,

I'm totally naive about human-powered airplanes, so flame me if necessary, but: has anyone tried to make human-powered aircraft that uses multiple "human engines"? i.e. would a "twin" with two people pedalling, or even a "slave galley" plane with 10 or 20 people pedalling have more or less trouble staying aloft?

Or, to put it another way, are there any economies of scale to be exploited by adding people to the engine?

Re:Multiple pilots?

[steveha]

has anyone tried to make human-powered aircraft that uses multiple "human engines"?

No. Here is the problem: the airplane needs to hold itself together, hold itself in the sky, and hold its pilot in the sky. Two pilots mean more weight must be held in the sky. That means the plane must be stronger, which means it must be heavier. And, check out the wing span of the Raven: 115 feet wide! Add another pilot and you need more lift, i.e. even bigger wings! Finally, there are drive train issues: transferring power from both pilots into the propeller means more mechanical gears and stuff, which is bad; you want that stuff simple, and thus light.

On a bicycle, you do get economies of scale when you add extra people. The main thing that slows a bicycle down is air resistance, and two people on one bicycle are aerodynamically very efficient. Also, a quality two-person bike weighs a little less than two quality one-person bikes, which is another economy of scale.

steveha

Not Lance

[steveha]

Maybe they could upgrade to a Pentium and convinced Lance Armstrong to give it a try...

I know this is a joke, but just for your information, their pilot Mike Eddy is an excellent choice. He is shorter than average, and built of muscle, and a world-class cyclist. I don't think Lance Armstrong is shorter than average, so I don't think he would work as well as Mike Eddy!

steveha

Raven news

[macpeep]

After surfing the site a little more, I ran across this news item, which was the most recent one on the site and seems to me to be of some significance to this story:

Wednesday, December 12, 2001
RAVEN Project closing - Paul
Raven team members,

It is with great regret that I must announce that the RAVEN Project is
shutting down. The numbers have caught up to the project. There just
aren't anymore resources available to for us to continue. At the end of the
year our lease expires and there is just enough money to cover that debt.
My financial position does not allow me the option of continuing any
further.

Powered by?

[A nonymous Coward]

This is getting ridiculous. It's bad enough saying a server is "powered by Apache", or "powered by Linux." Now we have a paper airplane "powered by a cpu".

Goodness gracious, is everyone afraid to say "controlled by"?

Re:A 16 MHz Proc?

[Alsee]

Re:A 16 MHz Proc?
they made it to the moon on far, far less.

Yeah, but the pilots weren't busy peddling.
Now there's an amusing image!

"Huston ... (huff, puff) ... the Eagle ... (huff, puff, huff, puff) has ... (huff, puff) ... landed.
Whew! (huff, puff)
Taking nap. (huff, puff)
Eagle out. Click "

-

Rockets must obviously be nonsense

[leonbrooks]

Given two equally equipped airplanes, it's kinda common sense that the one that isn't on fire will fly longer and farther.

In the case of jet-powered or rocket-powered airplanes (think Nebelwurfer) it's the one not on fire which falls out of the sky.

Elastic bands are the only safe way. (-: