Swiss helicopter pioneer-Stierlin

[Cita]

Nice video of the Swiss helicopter pioneer Robert Stierlin,a mechanic who succeeded in designing/building several helicopters.

http://www.youtube.com/watch?v=3aX1W7iWwuo&feature=related

enjoy !!

[Arnie Madsen]

Some very good historical video Cita. I enjoyed it very much. For a self taught home builder in 1954 this guy accomplished a lot. I came across another link on the helicopter history site with 2 pictures. http://www.helis.com/UpTo50s/f_stie.php

Great video. Thanks.

[rhoadsrunner]

Britta and I were at the Tucson International Airport today for the first US solo flight of the Dragonfly DF1. It did hover at about 2 feet, but due to varying rotor rpm's, and nervousness due to wind (unknown handling characteristics) and the number of spectators (including the Channel 4 news), test pilot Jerry Hains made the correct piloting decision to hold off for another day.

Avimech CEO and developer of the DF1, Ricardo Cavalcanti, purchased the rights to the hydrogen peroxide powered craft and is working with SwissCopter in getting ready for the unveiling at Osh Kosh this year. He is nearly ready to start production. At this time, it will only be available as a factory built craft and will not be sold as a kit.

In the video, you will see the Swiss pilot hand pumping the fuel delivery pump to start the flow of hydrogen peroxide to the tip jets. Once the combustion process starts, the energy of the rotor then turns a fuel pump which continues to supply fuel to the tip jets. According to the designer, the tip jets develop 102 HP each. I held them - they seem to weigh about 2 lbs. A new more efficient jet is being developed and will put out 200 HP. The current jets run on 80-84% solution. It is too expensive ($44.00 per gallon), therefore, the new more efficient jets will run on 70%, which is a bit cheaper at $2.57 per gallon.

The best way to describe the noise it makes is "a very intense hissing sound". It was uncomfortable enough that I had to plug my ears. There was some vapor coming from the exhaust, but nothing like the video where (as I understand) it was 2 degrees for the flight made in Switzerland.

The overhead cyclic is also the collective and torque control. Although there is no torque from the rotor, there is a tail rotor to aid in turning capability. Moving the cyclic left, right, forward and back allows the craft to move laterally, up and down movement controls the collective, and a twist grip changes the pitch of the tail rotor. The left hand controls the throttle which is on the end of the collective lever. One of the things Jerry complained about today was the sensitivity of the throttle in maintaining a stable rotor RPM. The craft seems to develop good lift (18 foot rotor) and only weighs 220 lb., so that may have something to do with it.

The rotor is extruded and uses the NACA 9-H-12 airfoil, which looks to be very similar to Dragon Wings. All parts are very well designed and constructed - overall very impressive.

Ricardo had planned to bring the craft to the Chapter 15 SW Regional Fly-In, but plans went awry at the last minute for him. We are trying to convince him to demonstrate it at Mentone this year on the way home from Osh Kosh. He is not sure about that timing, since his helper needs to get back for work.

If anyone is interested, we will try to keep you posted on what is happening with the DF1

Mark

Check out the following links:


http://www.tipjetusa.com/

http://www.marketwire.com/press-release/Innosuisse-Corp-Launches-Modern-Test-Site-SwissCopter-Huge-Demand-SwissCopters-DragonFly-891101.htm

YouTube - H2O2 helicopter demo test tip-jet Dragonfly DF1 2009 (http://www.youtube.com/watch?v=CGcRgEuCocQ)

[Timchick]

Sounds complicated to fly.

[C. Beaty]

Here’s another H2O2 powered helicopter:

http://www.aviastar.org/helicopters_eng/kellett_xr-15.php

[hillberg]

The cost of H202 and the noise ,put this idea to bed ,Didn't like the handeling looked unstable on landing and take off.....

[brett s]

The current jets run on 80-84% solution. It is too expensive ($44.00 per gallon), therefore, the new more efficient jets will run on 70%, which is a bit cheaper at $2.57 per gallon.

That second price can't be right - even adding a zero still sounds low, the end price comes down to how much H2O2 it contains & you're just diluting it further.

[C. Beaty]

Brett, I expect the price of H2O2 is a reflection of handling costs. At high concentrations, it is a dangerously explosive material; a drop on dry grass catalyzes the stuff and results in a mini fireball.

A pint of 3% solution at Wal-Mart is cheaper than a pint of water.

Hydrogen peroxide is used in vast quantities for bleaching wood pulp. Without it, your newspaper would be a dingy gray.

The trick is to buy industrial H2O2 and concentrate it yourself.

[hillberg]

Had a friend wanted to do a tyler rocket belt,the h202 had to come from Germany and was 50% solution and needed further processing,he figured it would cost $1500 for each 35 second flight,,,,,no need how the cost changed his mind....

[BEN S]

sells the equipment to distill whatever hydrogen peroxide strngth you need. its expensive but you would quickly pay for itself if you were using the fuel.
Ben S

[brett s]

$16,000 for that distillation machine would sure buy a lot of gas!