3 ms·

Siemens Electric Airplane Flies Us Toward the Future

37 points by Osiris30 10y ago

coldcode 10y ago
How does the engine compare to a piston engine in terms of equivalent HP?
- Intermernet 10y ago
  According to this[1] it's a 350HP electric motor. [1]: https://youtu.be/T_9-V73nT1k https://youtu.be/T_9-V73nT1k
tgb 10y ago
I'm surprised it's "nearly silent". I would have thought that the rotors, not the engine, were the bulk of an plane's noise.
- Noseshine 10y ago
  Try standing next to one even at low rpm. Rotor noise becomes a factor at high rpm, but then the engine still is noisy itself. As a private pilot, small-aircraft engines are noisy as f... Among the reasons: No development at all for about two decades when the small-aircraft market was down (which is why you see so many built decades ago, then a big gap, and only in the late 1990s new developments started to come to market). Other reason, but it's part of the first one (due to the costs involved): being conservative. If you only have one engine and you have a very reliable one, that's what you keep using. Especially when the costs of developing something new and getting it approved - and you have to repeat that in different regions with different government agencies - are very high. It is true though, when a propeller airplane flies overhead you get significantly more noise when it is directly perpendicular, when you get the most noise from the propellers. Jet engines had a significant positive development in this area. On the small Livermore (CA) airport I had the chance to compare two small jets, an old one and a new one. The old one made me cover my ears. The new one - less noise than a Cessna, quite amazing. In this context, an anecdote, but about noise on the inside: I always thought sitting in a glider would be quiet. It is - if you keep the little window shut. But then the cabin heats up too much (at least flying in California). I was very disappointed about my 1 hour in a glider. On the other hand, sitting inside a small airplane the noise from the engine is significant and a big reason why you really want that active noise-cancelling headset. I can relate to this pilot (except that if he had used a good headset he could have had it much easier): http://www.askthepilot.com/small-plane-misery/ http://www.askthepilot.com/small-plane-misery/ Tip: When flying in a small piston-powered airplane, always bring a good isolating headset, or ear plugs (or even both!). The movies are lying, those cockpits are as noisy as... I can't think of an equivalent, but it's on an "industrial level". Noise is a major stress factor in small aircraft aviation, as you could see from that pilot's article.
  - tgb 10y ago
    Interesting, thanks.
ZeroGravitas 10y ago
The most recent episode if "fully charged" was also about a prototype electric acrobatic plane: https://m.youtube.com/watch?v=Xe1g1JrRRkY https://m.youtube.com/watch?v=Xe1g1JrRRkY It reminded me of Tesla's evolution, where they found a niche where they can apply the benefits of electrics and rethink some basic elements of the platform most notably in the double propellers.
- dghughes 10y ago
  Fully Charged is an interesting show but the more I watched it I found it draining how Robert Llewellyn would put down all non-electric vehicles on every episode; almost every breath. I agree electric vehicles are great but even jokingly complaining about gas engines all the time gets annoying pretty quick.
- rebootthesystem 10y ago
  I've been flying electric powered high performance model airplanes (mostly F5B class) for decades. I'd like to think the electric r/c flight industry has been trenching this territory for quite some time. With the next 2x improvement in battery energy density cars and possibly full scale planes are going to make a huge leap forward. Here's a video of F5B class R/C planes. It's hard to convey just how insanely fast these things are. Huge power to weight ratio and very aerodynamically efficient. You can hear the crowd gasping at the performance they see. Also note that the motor is only turned on for a second or less at at time. If the motor were on longer these planes would reach 1,500 feet in 5 to 10 seconds tops. https://www.youtube.com/watch?v=T0z9iy2SJA0 https://www.youtube.com/watch?v=T0z9iy2SJA0
savrajsingh 10y ago
They never said anything about batteries and efficiency, the primary constraint holding back electric aircraft.
- msandford 10y ago
  Exactly, sure the motor is super light. Great. What happens when you put enough batteries in the airplane for a ~2 hour flight? Just assume that at cruise it's only using 1/2 of the rated power. OK, now where do we find a 260kWh battery pack light and small enough to fit in the plane? That's a full 3x of Tesla Model S battery packs.
- jopython 10y ago
  Unless we have high density super batteries electric vehicles will become a fad.

37 points by Osiris30 10y ago

coldcode 10y ago

How does the engine compare to a piston engine in terms of equivalent HP?

Intermernet 10y ago
According to this[1] it's a 350HP electric motor. [1]: https://youtu.be/T_9-V73nT1k https://youtu.be/T_9-V73nT1k

tgb 10y ago

I'm surprised it's "nearly silent". I would have thought that the rotors, not the engine, were the bulk of an plane's noise.

Noseshine 10y ago
Try standing next to one even at low rpm. Rotor noise becomes a factor at high rpm, but then the engine still is noisy itself. As a private pilot, small-aircraft engines are noisy as f... Among the reasons: No development at all for about two decades when the small-aircraft market was down (which is why you see so many built decades ago, then a big gap, and only in the late 1990s new developments started to come to market). Other reason, but it's part of the first one (due to the costs involved): being conservative. If you only have one engine and you have a very reliable one, that's what you keep using. Especially when the costs of developing something new and getting it approved - and you have to repeat that in different regions with different government agencies - are very high. It is true though, when a propeller airplane flies overhead you get significantly more noise when it is directly perpendicular, when you get the most noise from the propellers. Jet engines had a significant positive development in this area. On the small Livermore (CA) airport I had the chance to compare two small jets, an old one and a new one. The old one made me cover my ears. The new one - less noise than a Cessna, quite amazing. In this context, an anecdote, but about noise on the inside: I always thought sitting in a glider would be quiet. It is - if you keep the little window shut. But then the cabin heats up too much (at least flying in California). I was very disappointed about my 1 hour in a glider. On the other hand, sitting inside a small airplane the noise from the engine is significant and a big reason why you really want that active noise-cancelling headset. I can relate to this pilot (except that if he had used a good headset he could have had it much easier): http://www.askthepilot.com/small-plane-misery/ http://www.askthepilot.com/small-plane-misery/ Tip: When flying in a small piston-powered airplane, always bring a good isolating headset, or ear plugs (or even both!). The movies are lying, those cockpits are as noisy as... I can't think of an equivalent, but it's on an "industrial level". Noise is a major stress factor in small aircraft aviation, as you could see from that pilot's article.
- tgb 10y ago
  Interesting, thanks.

ZeroGravitas 10y ago

The most recent episode if "fully charged" was also about a prototype electric acrobatic plane: https://m.youtube.com/watch?v=Xe1g1JrRRkY https://m.youtube.com/watch?v=Xe1g1JrRRkY It reminded me of Tesla's evolution, where they found a niche where they can apply the benefits of electrics and rethink some basic elements of the platform most notably in the double propellers.

dghughes 10y ago
Fully Charged is an interesting show but the more I watched it I found it draining how Robert Llewellyn would put down all non-electric vehicles on every episode; almost every breath. I agree electric vehicles are great but even jokingly complaining about gas engines all the time gets annoying pretty quick.
rebootthesystem 10y ago
I've been flying electric powered high performance model airplanes (mostly F5B class) for decades. I'd like to think the electric r/c flight industry has been trenching this territory for quite some time. With the next 2x improvement in battery energy density cars and possibly full scale planes are going to make a huge leap forward. Here's a video of F5B class R/C planes. It's hard to convey just how insanely fast these things are. Huge power to weight ratio and very aerodynamically efficient. You can hear the crowd gasping at the performance they see. Also note that the motor is only turned on for a second or less at at time. If the motor were on longer these planes would reach 1,500 feet in 5 to 10 seconds tops. https://www.youtube.com/watch?v=T0z9iy2SJA0 https://www.youtube.com/watch?v=T0z9iy2SJA0

savrajsingh 10y ago

They never said anything about batteries and efficiency, the primary constraint holding back electric aircraft.

msandford 10y ago
Exactly, sure the motor is super light. Great. What happens when you put enough batteries in the airplane for a ~2 hour flight? Just assume that at cruise it's only using 1/2 of the rated power. OK, now where do we find a 260kWh battery pack light and small enough to fit in the plane? That's a full 3x of Tesla Model S battery packs.
jopython 10y ago
Unless we have high density super batteries electric vehicles will become a fad.