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lughnasadh OP t1_j5gmdtm wrote

Reply to comment by angrathias in Seattle-based Jetoptera is developing a vertical takeoff aircraft that can travel at almost 1,000 km/h with a radically simplified new type of engine. With almost no moving parts, it uses super-compressed air to create vortexes for thrust. by lughnasadh

>>Don’t normal aeroplanes already cruise at like 900kmh? What’s the big difference ?

Jet airliners (Boeing, Airbus, etc) are about the same speed, but this engine isn't competing with those.

This design only works on smaller planes. So this is faster than most of those, and it seems quieter, more fuel efficient and cheaper to maintain.

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gerkletoss t1_j5i5yxt wrote

How small are we talking here? Also, can that thing glide?

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caspy7 t1_j5iaqxi wrote

Most things can glide given the right conditions. 😁

More seriously, I'm no aviation guy but gliders tend to have longer wings and are light particularly because of their lack of engines. So while traditional planes can glide some, the compactness of this design makes me think it would be especially poor at gliding.

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polar_pilot t1_j5id2p3 wrote

Yeah the glide range of this thing would be abysmal, and the speed with which it would achieve best glide distance would probably make an emergency landing/ crash far less survivable. Perhaps it’ll come with a parachute system?

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caspy7 t1_j5ieffe wrote

Traditional planes can glide some and hit the ground at a more gentle angle and do I recall that helicopters do some slow rotator spin to make landings more survivable?

That was something that came to mind, if these are an improvement on helicopters that'd be great, but if they became known as deathtraps when the engine fails it could tank the tech forthwith.

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theBytemeister t1_j5ifvau wrote

Autorotation. If you really want a better understanding of what is happening, read up on autogyros. They are essentially a helicopter in auto-rotation that is pushed around with a propeller.

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gerkletoss t1_j5ifcyc wrote

>and do I recall that helicopters do some slow rotator spin to make landings more survivable?

Aurorotation. The airflow through the rotor reverses and the spinning creates a ton of drag.

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polar_pilot t1_j5ifmvd wrote

Yeah the more wing you have the better you can glide- more or less. An airliner can glide a LOT better than an f-16. Helicopters can do what’s called an auto-rotation, the airflow over the blades creates lift and spins them- same principle as a gyrocopter- thus slowing descent. A parachute would be the only way this thing makes sense. I imagine it would be installed considering they’re not hard at all to put on a composite frame aircraft

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gerkletoss t1_j5if6wl wrote

I was wondering about emergency landings, not gliding as plan A

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NotShey t1_j5k3lys wrote

>So while traditional planes can glide some,

Glide ratio of a typical airliner is around 17-20:1 (17 miles horizontal for every 1 mile vertical). Highly maneuverable aircraft are where you tend to see abysmal glide ratios. I don't believe it's publicized anywhere, but I suspect your typical F-35 glides about as well as a brick.

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im_thatoneguy t1_j5krfc9 wrote

Their first RC plane scale prototype was on a glider.

It's just an alternative to turboprops or turbofans, so sure you could attach it to anything. You could attach a turbofan to a "glider".

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Renovateandremodel t1_j5i8n9x wrote

I’m curious as to the sound of it, and wondering if the sound can be dampened down to a point of 80 db?

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