The Red Bull Flugtag is returning to Austin on August 25, 2007. Exciting times. I really like the idea of this competition. It gets the creative juices flowing and gets most of my friends talking in excited tones about all the great stuff that we could do if only we had enough time, money, patience, etc. Here is a video of one of the 2004 events
Video Provided by Red Bull Flugtag USA
If you visit the page linked at the top you will find a tab which contains the rules for the competition.
- Human Powered. Specifically direct human muscle power. No external power sources or “stored” energy.
- Less than 30′ wide.
- Less than 450 lbs. The rules are a little unclear on whether this weight includes the pilot or not.
The last time the Flugtag came through town was in 2003. I planned and schemed for several months but ultimately never did anything about it other than make a spreadsheet full of calculations. The key to the nefarious plan was the brainchild of Ralph. If you were ever a child you are probably familiar with the idea of a water rocket. Take a plastic soda bottle and fill a quarter to a third full of water. Plug the mouth of the bottle with a cork which has had a bicycle pump inflation needle stuck through it. Turn the bottle up so that the water is between the air in the bottle and the cork. Pressurize the bottle with the pump until the cork is forced out. At this point the compressed air forces all the water out the bottom and the bottle shoots up into the air. Now imagine one of these except with a 50 gallon capacity, 20 gallons of water, an internal diaphragm that will allow it to work laying on its side and a quarter-turn ball valve instead of a cork so you can control when it goes off. Unfortunately this thing has to push ~150 lbs of pilot and another 100 lbs of airplane. Once you add all that in and do the math you only get going about 25 mph while staying inside the rules.
In the intervening four years the rule set has been modified slightly to prohibit the use of “stored” energy (flywheels, pressurized air, twisted up inner tube) in addition to the historic external energy (catapult, internal combustion engine, solid rocket booster) so the idea of dumping 5 minutes of pedaling into 5 seconds of launch has fallen by the wayside which is sad but probably for the best. Though creativity abounds I fear that sustained flight, even for as short as a few seconds, is not really in the cards for the competition now. Showmanship and a big splash are the order of the day and I am short on the former and uninterested in the latter.
Some interesting things I’ve seen in the videos of previous events are that vehicles that have a stand which holds them an additional 6′ or so above the runway seem to have a better shot a gliding. Also if you want to win everyone pushing needs to be willing to push right past the end of the ramp. If they pull up short to avoid going in it’s pretty much guaranteed failure. Flights that go well tend to end with the plane rolling and dipping a wing in the water. Keeping the thing level can get you extra distance and will make your landing less exciting.
I still think the thing needs to be powered. Probably a lightweight prop similar to the one used in the Gossamer Albatross. That design actually holds a lot of useful features. Aluminum and kevlar frame members, mylar wing coverings. The wings were about three times longer than what the Flugtag allows and the power source was a professional cyclist who could provide more than the minimum 200 watts necessary for the sustained flight. The launch is also important. The plane with its propeller alone will not be able to get to speed in time to fly on the length of runway provided. The people helping the plane get started need to get it up to a reasonable speed before it reaches the end of the platform. Hopefully that initial boost plus the prop and the drop off will get it in a gliding/lift mode before it gets wet. There are probably ways to get some mechanical advantage but the best launch catapult is probably still just tying ropes between the launch crew and the plane and throwing the crew off the deck. May as well use the whole gravity thing to your advantage. I don’t know how that counts towards your recorded distance. The rules are dissatifyingly vague in places but I guess that’s to encourage creativity. They can just say no thanks to anything that they think is unsporting but I think it would be better to know ahead of time to be able to design around the restrictions.
Now taking applications for test pilot for imaginary aircraft. Must like cycling at town lake, have strong immune system.
[audio:Fly_Me_to_the_Moon.mp3]
Fly me to the moon
So, there you go. Now I’m part of the problem. All blogging and embedding movies and musics up in and plugging up the intertubes with my junk. At least it’s not political.
– Eric