Rocket powered Dragonfly DF1 helicopter cleared for take-off

Rocket powered Dragonfly DF1 helicopter cleared for take-off
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The DF1 prepares for take off
The DF1 prepares for take off
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The Dragonfly DF1 is a helicopter that uses rockets attached to the tips of its blades to power it instead of a conventional fixed motor attached to the body. The rockets produce no pollution and are fueled by 70 percent hydrogen peroxide (H202) supplied by a pair if fuel tanks surrounding the pilot’s seat. They are capable of propelling the DF1 to a top speed of 185 km/h (115 mph) and can send the craft climbing to a ceiling of 4,000m (2.485 miles) at a rate of 700 m (2,300 ft) a minute.

The rocket chopper is apparently simpler and safer to fly than conventional helicopters as there are less flight controls and moving parts. It also offers improved stability as propelling the rotors directly results in less vibration. Plus, because there is no motor torque, the tail rotor is only required to rotate the helicopter and not for stability.

The DF1 prepares for take off
The DF1 prepares for take off

Tip-jet powered helicopters are nothing new. The Percival P.74 was a British experimental helicopter designed in the 1950s that employed tip-jet powered rotors but was unable to get off the ground due to its inadequate power source. The Hiller YH-32 Hornet built for the US Army and Navy also in the early 1950s exhibited powerful lifting capacity providing some hope for military uses, but the high noise, poor range, and high night-time visibility of the ramjet flames from the ramjet engines mounted on the blade tips also doomed this craft.

Tucson-based company, Swisscopter America’s Inc. has been able to overcome these shortcomings by using a pair of H2O2 rocket motors made by Tecaeromex that use a penta-metal catalyst in the motors to instantly dissociate the peroxide into 600 degree Celsius high pressure steam and drive the blades. The DF1 retains the traditional collective/throttle lever but steers via a motorbike-like control bar for tilting the rotor head. The DF1 also does away with any foot controls.

Although probably still not suitable for military uses the DF1 does boast some impressive specs. Its tanks hold 70 liters (18.5 gal) of fuel to provide up to 50 minutes of flight time at a cruising speed of 65 km/h (40 mph). This can be extended to 100 minutes with an optional extra 60-liter (16 gal) fuel tank. Empty the helicopter weighs a mere 106 kg (234 lbs) and can carry up to 227 kg (500 lbs) including pilot and fuel.

Other options include a windshield canopy, crop spray system, rescue hammock, cargo compartment, fire extinguisher, autopilot, winch, more powerful engines and navigation and landing lights.

Swisscopter has conducted test flights of the DF1 and obtained airworthy certificates ahead of an expected commercial launch of the DF1 this year. Interested parties can reserve their place in line for the DF1 on the Swisscopter website now. The company is also testing an experimental two-seater prototype using the same technology.

Via Red Ferret.

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This is a beautiful concept!!! I tried to see what the cost of H2O2 was per gallon at 70%!!! And the extra precautions you have to go through just to transport this fuel at a concentration over 8%!!!
Unless you can make Hydrogen Peroxide at a 70% level somehow safer and cheaper, this will never be anything but a rich man\'s toy.
25 gallons for 100 minutes of flight??? You have to either fly from one place and come back there or fly from one filling station to the next.
I love the vehicle but I need more info on the cost of running it.
Facebook User
Great idea...they need to keep working on the noise aspect if it needs to gain wide popularity, although in niche areas like crop spraying this should not be a problem. Another headache is the fuel of course. My best wishes with the team.
An amazing concept. The noise is a bit scary, and the main drawback would appear to be the fuel, which I believe is quite nasty to handle. The Germans used it in the ME-163 rocket plane, which combined it with another chemical which I can\'t remember. There were some bad accidents. This system is safer, obviously. Another idea would be a paraffin heated steam generator, using water. If noise was no problem, how about small V1 type pulse jets on the tips?
Facebook User
The Sud-Quest (later Aerospatiale, now Eurocopter) Djinn used a cold-flow tip-jet rotor. It bled air from the compressor section of a small gas turbine out to angled nozzles at the rotor tips.
That\'s the only tip-jet helicopter to be commercially produced, about 180 were made in the 1950\'s and 1960\'s. A modern version would use a more efficient axial flow engine instead of the centrifugal flow turbine common in the early years of the jet turbine.
Craig Jennings
Oooh, imagine the savings on maintenance!!!!!! Ok, force x length = torque. Which is what you need for start up etc etc. I wonder if they couldn\'t have a second set of jets mounted further towards the axis/hub to be used once things are up to speed? Moveable jets would be cool but complicated and more dangerous... so a second set of jets perhaps? Could someone with a large brain and a pocket protector comment on this? Cheers ;)
Jan Klok
These jets probabaly do better propelling a small air ship. Faster, more economical, more payload. Is there a les efficient way to use rockets than on the tips of a heli? :-)
Totally love the no-torque part, though.
Will, the tink
Hey windykites1, A pulse-jet propelled helicopter was advertised in the back of Pop-sci and Pop-mx for years! It too was probably a pretty good noise maker!
I would rather douse myself in jet fuel and light a cigarette than sit in a helicopter next to a tank of 70% H2O2.
Joe Wesson
one way to lower the noise output would be to flatten out the exhaust nozzle to a thin ribbon and tune it to a frequency above that of the range of hearing. i don't know how to calculate the required output volume and how much of the rotor's trailing edge it would take. i guess i could figure it out if i had to. but it's worth a shot at r&d if you have the rest of the thing built already.
:) .