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As a pilot I would never step foot in this thing. The thought of being in an aircraft with zero aerodynamic control, or ability to glide in a dead stick situati
by aphextron 10y ago
As a pilot I would never step foot in this thing. The thought of being in an aircraft with zero aerodynamic control, or ability to glide in a dead stick situation is a complete nightmare. It doesn't matter how redundant your systems are if you have a fundamentally unstable airframe with no yaw control. In a total power loss situation, you must have some type of glide profile. All other forms of aircraft have this. Such a design would be fine for drones, but this will never carry humans.
- dm_i386 10y agoHow is the glide profile any worse than a helicopter's?
- dingaling 10y agoHelicopters glide or 'autorotate' tolerably well after engine or driveshaft failure, at least enough to land controllably. In the R22 two-seater the best glide ratio is about 4:1 ( 4ft horizontal for 1ft drop ) and those at my local airfield practice autorotation to landing all day long. Apparently the worst helicopters for autorotation are those with Kamov's superimposed coaxial rotor system, which struggle to reach 2:1 for some aerodynamic reason I don't know.
- TylerE 10y agoIn a helo you can attempt auto-rotation, which while tricky at least gives you a fighting chance.
- aphextron 10y ago>How is the glide profile any worse than a helicopter's? This is a common misconception. Helicopters can glide to a landing just like airplanes.
- ominous_prime 10y agoHelicopters glide quite nicely. Learning to autorotate is something you learn early on when getting your license.
- tristanb 10y agoRockets, balloons, most military aircraft? Shove a ballistic parachute on it.
- tylorr 10y agoOn the technology page under the safety first section they talk about a parachute being installed as a last resort.
- aphextron 10y ago> "Rockets, balloons, most military aircraft? Shove a ballistic parachute on it." As far as I know, no rocket or military fighter jet has ever been certified to carry paying passengers for exactly this reason. We're talking about shuttling people around, not highly trained test pilots. Balloons are actually far safer than fixed wing aircraft for other reasons. It would take a complete loss of the canopy for a balloon to fall out of the sky. When they run out of fuel, they just drift slowly to the ground. Ballistic parachutes are a last resort option, and add a large amount of weight and complexity to the aircraft. Not to mention that they do not scale up to larger passenger aircraft. It's not even comparable to the safety afforded by a stable airframe.
- tristanb 10y agoYou cant dead stick a cessna in an urban environment, and current ballistic parachutes aren't that heavy. https://aviation.stackexchange.com/questions/24946/what-is-the-weight-of-ballistic-recovery-systems https://aviation.stackexchange.com/questions/24946/what-is-t...
- aphextron 10y ago>You cant dead stick a cessna in an urban environment, and current ballistic parachutes aren't that heavy. Except a ballistic parachute does absolutely nothing for you in the scenario where > 90% of accidents happen: take off and landing. Even the most advanced BRS systems on Cirrus planes require 1000 feet AGL. There's simply no getting around the basic physics of this problem.
- deleted 10y ago[deleted]
- gdudeman 10y agoIs this dissimilar to a helicopter though?
- snerbles 10y agoHelicopters can auto-rotate, "gliding" on the momentum of the main rotor. This allows for a controllable landing under loss of power. There have been rare cases where a mechanical failure seizes the main rotor, such as the crash of the WNBC news chopper (N8617B) in 1986. This particular incident was caused by poor maintenance, however. https://en.wikipedia.org/wiki/Autorotation https://en.wikipedia.org/wiki/Autorotation http://www.check-six.com/Crash_Sites/Dornacker-N8617B.htm http://www.check-six.com/Crash_Sites/Dornacker-N8617B.htm
- astrodust 10y agoA helicopter can auto-rotate, though that's really the least-bad option if you're in that sort of situation. It turns an assuredly fatal scenario into a hopefully, maybe, possibly survivable one: https://aviation.stackexchange.com/questions/14605/how-does-a-helicopter-pilot-execute-an-auto-rotation-landing https://aviation.stackexchange.com/questions/14605/how-does-... Here's a demonstration: https://www.youtube.com/watch?v=BTqu9iMiPIU https://www.youtube.com/watch?v=BTqu9iMiPIU
- jimbokun 10y agoHaha! That Neil DeGrasse Tyson, what a dummy. (Good sport, though. And I also thought a helicopter would drop like a rock without power.)
- astrodust 10y agoIt drops like a rock if the Jesus Nut (https://en.wikipedia.org/wiki/Jesus_nut https://en.wikipedia.org/wiki/Jesus_nut) fails, but that situation is freakishly rare.
- lookACamel 10y agoSo similar to how a maple seed glides?
- esemor 10y agoThis guy!
- walrus01 10y agoIf equipped with a parachute like a Cirrus I would not be so scared of it. In its current iteration it's about as scary as the eHang giant octocopter.
- bobsil1 10y agoParachutes generally need 1K feet to be effective, and VTOL cabs will operate at fairly low altitudes. Maybe there are special ops low-altitude parachute designs that can be adapted for airframes.
- ENGNR 10y agoAs a non-pilot, that's ultimately the reality every time we fly already. Sure there's redundancy, but ultimately if things go wrong all we can do is sit powerlessly in our chair as the ground roars up at us.
- manigandham 10y agoThe post is talking about unpowered glide profile - the vast majority of air travel is in commercial jetliners which can and do glide, providing a major advantage in case of problems.
- whazor 10y agoThe plane they are planning to build looks like it could glide by itself.