This is especially important for helicopters, according to Chretien. He observed that most helicopter crashes result from pilot error, followed by mechanical failure. Though the mechanisms behind helicopter flight are complex, the mechanical underpinnings are old and haven't changed much since helicopters were first developed, despite the preponderance of modern electronic instruments.
"It didn't make sense to me that the most advanced platform would be running on medieval technologies," he said. "It's an issue when it comes to reliability."
That's not to say electrics are without their troubles. As a new technology, electric propulsion is not necessarily more dangerous, but the field is less mature than conventional flight. After breaking the speed record, Yates' plane was forced to make a dead-stick landing when a malfunctioning cell knocked out power to the motor.
Storing the electrons needed to power an airplane also carries its own unique risks, as poorly cooled high-technology batteries can catch fire or explode.
Rotary aircraft are particularly challenging because their flight characteristics depend so much on weight and relative power. Even Sikorsky Aircraft Corp., one of the world's largest helicopter manufacturers, struggled with developing an electric aircraft and scrapped plans to test a prototype last year, citing safety concerns.
Chretien's prototype electric helicopter is scarcely more than steel tubing and a chair. Powered by up to 600 amps from 128 pounds of lithium-ion polymer batteries, the contraption can fly using two pairs of counter-rotating coaxial blades for up to 12 minutes.
Though it is just a proof concept, he said the industry is due for another technological leap now that manufacturers are getting diminishing returns from developments in turbines and piston engines. "If we can succeed in helicopters, the fixed-wing market will be a breeze," he said.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
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8 Comments
Add CommentNagnostic,
Reply | Report Abuse | Link to thisI'm sure we can all agree you need to improve your online searching and navigation skills. It's quite telling.
Nagnostic, it's all a bit esoteric, but try this:
Reply | Report Abuse | Link to thisType "curiosity mars" in the search box.
You'll get about 80 articles.
carbon frames, solar skin, non-flammable batteries, low BMI passengers--definite terrafugue implications--but how do we prevent duct-fans from scattering gravel at velocity thru nabors' windows.
Reply | Report Abuse | Link to this'nabors'? (people who nab?)
Reply | Report Abuse | Link to thisThe article states:
Reply | Report Abuse | Link to this"Storing the electrons needed to power an airplane also carries its own unique risks, as poorly cooled high-technology batteries can catch fire or explode."
While cooling components in an airplane would not likely be a problem in most cases, extended departure delays can occur. It also seems that there have been many cases where (very difficult to cool) laptops have caught fire or exploded apparently due to battery defects. Perhaps 'aviation grade batteries' (analogous to aviation grade gasoline) could be specified to meet more rigorous operational requirements...
The prototype plane here appears to be similar to a lightweight glider design, which would not likely meet durability requirements for general use aircraft. Significant increases in structural weight would have to be offset by significant increases in power and battery capacity - also incurring additional weight... Production feasibility has not been demonstrated by the prototypes I've seen.
what about some kind of Hybrid. say something that uses electric for takeoff and landing. and some kind of Ramjet that kick in when certain speeds are reached
Reply | Report Abuse | Link to thismjacks2,
Reply | Report Abuse | Link to thisUm, you're thinking a propeller driven craft could get a plane up to Ramjet speed? They don't even work below 300MPH, don't even begin to be efficient below 600MPH, and work best a mach 2-4. Ramjets are only efficient when working within fixed pressure and speed conditions, so don't think it could be used to accelerate from 300 to whatever MPH either.
Hybrid automobiles gain much of their efficiency from being able to shut the gasoline engine off during stops at red lights etc. and by using breaking to recharge batteries. As a pilot with many hours in light planes, 300,000 lb jets and mach 2 fighter airplanes, I can see many advantages to using some of the same principles for aircraft. The takeoff and climb phase of flight eat large amounts of energy but also stores it as potential energy as altitude. Many large aircraft have a better glide ratio than light planes and can convert altitude to distance very efficiently without engines running, and stopping an airplane after touchdown that weighs more than several deseil train engines generates a trmendous amount of energy as wasted braking heat. Not much we can do about getting an airplane to altitude but cruise is fairly efficient and descent and landing are energy producers. Hybrid aircraft can capitalize on this in much the same way automobiles do.
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