With coaxial rotors, the top and bottom rotors spin in opposite directions, thus counteracting the rotational pull, or torque effect of conventional helicopters. Coax rotor helicopters therefore don't need a tail rotor. The tail rotor of conventional helicopters consumes up to 25% of the energy to stabilize them and prevent them from spinning around. The coax rotor helicopter therefore has a much better power to weight ratio. Importantly, coax helicopters are also much quiter than conventional helicopters. Tail rotors add around 30-40% of the noise a helicopter makes, due to the main rotor wash impacting the tail rotor wash.
Back in August, WHT accelerated development of their electric aerial vehicle option, by selecting and securing electric motors, controllers and suitable batteries to make the electric helicopter a reality.
At the moment, the electric option will only allow up to 35 minutes flying time, but the range all depends on what batteries are selected. According to Sean, WHT are about to start testing a hydrogen option, in order to further extend the range.
Links:
http://www.wielandhelitech.com - WHT
Coaxial Helicopter Attributes - WHT
Twin Rotor Technology - WHT
Video:
Co-axial Rotor Helicopter - The New Inventors (abc.net.au)
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Comments: 16
I've seen small, battery operated toys like this coaxial rotor helicopter for years. Finally they've made it real.
35 minutes, though, keeps it experimental... but with nanotechnology and newer batteries, the sky ought to be the limit...
I've not flown in a helicopter, but my Dad did, and he said that, apart from heavy turbulence and vibration, it was very loud. I would think that the electric motor would be much quieter than a conventional engine. A green and kinder gentler helicopter, perhaps?
While the 35 minutes flying time of the current model may seem short, as I said, the range all depends on what batteries are selected, taking into account cost, capacity, lifetime, number of charging cycles, charging time, size, weight, availability, cooling required, etc.
Having said that, one can cover a lot of ground in half an hour with a helicopter. These helicopters can fly at speeds over 200 km, there is no need to line up and wait before traffic lights, there's little or no traffic congestion (there's more space in the 3-dimensional air than on the 2-dimensional ground) and one can fly directly from point A to point B, without having to follow winding roads and stay behind slow vehicles. So, one can reach one's destination much faster than when traveling by car, bus, or other type of transport.
So, not only can these kind of helicopters easily fly from one point to another, one doesn't need airstrips, traffic control guidence, etc. One doesn't even need a helipad. It's ideal for dropping someone off in their backyard. While there may be all kinds of regulations currently making it difficult to indeed hop between backyards, parks and rooftops to visit people, go shopping or go to work, I do expect that GPS-navigation, radar and other sensors and computer control can provide sufficient safety to make this legally acceptable in many cases. Given that this design promises easy and reliable flying, without much need for training, I believe that this way of transport can actually be safer than travel by car.
Furthermore, since traveling in such helicopters doesn't require roads, there should be substantial savings in the infrastructure required, compared to cars, buses, trains, etc.
Most importantly, this can be a zero-emission way of transport, if the electricity comes from clean sources, such as solar and wind energy.
So, I'm in, once the lottery check arrives (this is so much more appealing than a gas-guzzling corporate jet, and my backyard isn't big enough for a landing strip that would accommodate jets). Of course, the overhead electrical wires would be a problem for the helicopter, but maybe we can bury those along with the Republican party. That could be a community project. :) Thanks again for the nice article.
- they are a safety hazard, people get killed especially during storms
- the poles are a traffic hazard
- they make access difficult for high vehicles, such as removal trucks
- they prevent trees being planted underneath and building on access strips
- they are an eyesore
- they can cause interference with broadcasting and communications
- there are disputed claims that they cause cancer
- the burden of maintenance and inspections is high, for landowner, utility and community
Burying cables can be quite expensive, especially in rocky and uneven places where people live far apart. It requires digging up streets and gardens, which is inconvenient, but once it's done it often turns out to be cheaper in the long run.
The problem is that not everyone can afford the upfront cost. Local communities therefore often subsidize a transition to buried cables. The fact that overhead wires and electricity poles make it difficult for helicopters to land in and take off from backyards just adds another argument for buried cables.
The grid needs to be renovated anyway, to enable high speed battery recharging and discharging, and grid-connected facilities that produce clean energy, such as solar panels and wind turbines. Thus, why not take the transition to buried cables along board as well.
The same applies to telecommunications wiring and poles, noting that this can off course be resolved more easily by switching to wireless transmission. What's your take on wireless (microwave) transmission of electricity between buildings?
Electric helicopters will still be expensive, costing more than cars, but mass production should bring cost down. As I noted above, they also come with savings in infrastructure such as roads, highways, gasoline stations, bridges, tunnels, etc.
In conclusion, let's welcome the advent of the electric helicopter.
While this is not an electric helicopter, I can well see an electric version coming up in future. For those interested in the regulatory aspects, have a look at the US Ultralight Society for more on aircraft requirements, pilot certificates and flying restrictions.