4 ms·

I'm interested to see how quiet it's going to be over the skies of downtown Vancouver and Victoria if they manage to get the whole fleet to electric

acwan93 6y ago
Do electric planes make any difference in terms of noise? When an electric vehicle is in motion most of the noise I can tell are from the tires. A electric powered propeller plane would most likely still have most of its noise generated by the propeller, not the internal combustion engine. I presume the same is with jets.
- bdamm 6y ago
  High torque at lower RPMs is still an untapped potential of electrification for aviation. Having more options for placement of propeller (behind the rudder, for example, where a larger and slower propeller could be placed) is huge. NASA is also experimenting with many small propellers placed ahead of the wings which can result in higher efficiency at cruise, but unfortunately doing their most work when the plane is flying slowest (just before landing). We'll see! But many exciting possibilities.
- jillesvangurp 6y ago
  Yes in several ways: - No noise when idling and more fine grained control over power. You can't tell apart a plane that is idling from one that is completely off with electric. Some turbo props on the other hand provide so much thrust when idling that you need to be on the brakes or it will start moving to quickly during taxiing. So, that amounts to a lot less noise for electrical planes while the plane is on the airport (i.e. where noise matters the most). - Not all propellers are made the same. They are generally matched to torque and rpm that can be provided by the engine. With an electric engine you'd have a wider range of both as the engine torque and rpm are more easily controlled. That means you can optimize for performance, noise, or both more easily. - Generally propellers get noisy when their tips break the speed of sound. Bigger propellers mean this happens at lower RPM. Smaller propellers can spin faster without having their tips breaking the sound barrier. Electrical engines can be small and light; meaning that you can choose to have a lot of smaller, less noisy ones instead of the big noisy ones. Also, because they can deliver more torque, you can increase the number of blades on the propeller to deliver more thrust and power at lower rpm (at the cost of more drag). - The frequency of the noise matters too. High pitched noise doesn't carry very far. Low pitched noise can be heard miles away. Like the noise of tonnes of kerosine being burned when a big jet takes off. Not a thing with electric. Big combustion engines can be similarly noisy. It's part of what makes them sound so exciting. You are right they won't be whisper silent but they will be a lot more silent overall, and noisy far less often (only when they need to; basically during take off).
SkyPuncher 6y ago
There's a video in the article. Sounds a little bit quieter, but still a lot of prop noise.
- alex_duf 6y ago
  I think there's a helicopter around so it's really hard to judge
baybal2 6y ago
I only see benefits given that electric powertrain is much more reliable, and quieter than piston engines, and that engines have much higher chance to stall on takeoff.
- bdamm 6y ago
  Aero engines are exceptionally reliable and don't "stall". However, electric does have advantages; less costly to maintain (theoretically; this still needs to be actually proven) and the pilots will like the high torque available at lower RPMs. This can allow designs with slower propellers that in turn will lower prop noise.
  - baybal2 6y ago
    Big jet engines, and turboprops are. Small jet engines, turboprops, and piston engines stall many times more frequently.
    - steffan 6y ago
      I think you're misinterpreting reports of stall-related incidents as being an engine stall, but the most common accidents are related to 'aerodynamic stall'. Engine stalls are virtually unheard-of.
      - baybal2 6y ago
        > Engine stalls are virtually unheard-of. They do, and quite often https://airfactsjournal.com/2018/10/the-bad-news-and-good-news-about-engine-failures/ https://airfactsjournal.com/2018/10/the-bad-news-and-good-ne...
        steffan 6y ago
        The article does point out this: “And by far the most common reason piston engines quit is because they don’t receive fuel, either due to fuel starvation (the airplane has fuel but it doesn’t make it to the engine) or fuel exhaustion (the airplane truly ran out of it). These two causes account for over one-third of engine failure accidents”
notatoad 6y ago
It's been a few years since I was out on the coast, but I don't remember float plane noise being that significant of a factor in the city. The people who live near the harbours they land at in the gulf islands, or on that lake in Whistler are going to be pretty happy though.
TheRealPomax 6y ago
It's still going to be a propeller punching its way through air. The explosions may be gone, but prop noise isn't going anywhere.
- dan_quixote 6y ago
  As a Seattle resident in a common float plane flight path, the piston engines can be quite loud. You can hear them inside with windows/doors closed and moderate household noises (like a shower or washing machine).

acwan93 6y ago

Do electric planes make any difference in terms of noise? When an electric vehicle is in motion most of the noise I can tell are from the tires. A electric powered propeller plane would most likely still have most of its noise generated by the propeller, not the internal combustion engine. I presume the same is with jets.

bdamm 6y ago
High torque at lower RPMs is still an untapped potential of electrification for aviation. Having more options for placement of propeller (behind the rudder, for example, where a larger and slower propeller could be placed) is huge. NASA is also experimenting with many small propellers placed ahead of the wings which can result in higher efficiency at cruise, but unfortunately doing their most work when the plane is flying slowest (just before landing). We'll see! But many exciting possibilities.
jillesvangurp 6y ago
Yes in several ways: - No noise when idling and more fine grained control over power. You can't tell apart a plane that is idling from one that is completely off with electric. Some turbo props on the other hand provide so much thrust when idling that you need to be on the brakes or it will start moving to quickly during taxiing. So, that amounts to a lot less noise for electrical planes while the plane is on the airport (i.e. where noise matters the most). - Not all propellers are made the same. They are generally matched to torque and rpm that can be provided by the engine. With an electric engine you'd have a wider range of both as the engine torque and rpm are more easily controlled. That means you can optimize for performance, noise, or both more easily. - Generally propellers get noisy when their tips break the speed of sound. Bigger propellers mean this happens at lower RPM. Smaller propellers can spin faster without having their tips breaking the sound barrier. Electrical engines can be small and light; meaning that you can choose to have a lot of smaller, less noisy ones instead of the big noisy ones. Also, because they can deliver more torque, you can increase the number of blades on the propeller to deliver more thrust and power at lower rpm (at the cost of more drag). - The frequency of the noise matters too. High pitched noise doesn't carry very far. Low pitched noise can be heard miles away. Like the noise of tonnes of kerosine being burned when a big jet takes off. Not a thing with electric. Big combustion engines can be similarly noisy. It's part of what makes them sound so exciting. You are right they won't be whisper silent but they will be a lot more silent overall, and noisy far less often (only when they need to; basically during take off).

SkyPuncher 6y ago

There's a video in the article. Sounds a little bit quieter, but still a lot of prop noise.

alex_duf 6y ago
I think there's a helicopter around so it's really hard to judge

baybal2 6y ago

I only see benefits given that electric powertrain is much more reliable, and quieter than piston engines, and that engines have much higher chance to stall on takeoff.

bdamm 6y ago
Aero engines are exceptionally reliable and don't "stall". However, electric does have advantages; less costly to maintain (theoretically; this still needs to be actually proven) and the pilots will like the high torque available at lower RPMs. This can allow designs with slower propellers that in turn will lower prop noise.
- baybal2 6y ago
  Big jet engines, and turboprops are. Small jet engines, turboprops, and piston engines stall many times more frequently.
  - steffan 6y ago
    I think you're misinterpreting reports of stall-related incidents as being an engine stall, but the most common accidents are related to 'aerodynamic stall'. Engine stalls are virtually unheard-of.
    - baybal2 6y ago
      > Engine stalls are virtually unheard-of. They do, and quite often https://airfactsjournal.com/2018/10/the-bad-news-and-good-news-about-engine-failures/ https://airfactsjournal.com/2018/10/the-bad-news-and-good-ne...
      - steffan 6y ago
        The article does point out this: “And by far the most common reason piston engines quit is because they don’t receive fuel, either due to fuel starvation (the airplane has fuel but it doesn’t make it to the engine) or fuel exhaustion (the airplane truly ran out of it). These two causes account for over one-third of engine failure accidents”

notatoad 6y ago

It's been a few years since I was out on the coast, but I don't remember float plane noise being that significant of a factor in the city. The people who live near the harbours they land at in the gulf islands, or on that lake in Whistler are going to be pretty happy though.

TheRealPomax 6y ago

It's still going to be a propeller punching its way through air. The explosions may be gone, but prop noise isn't going anywhere.

dan_quixote 6y ago
As a Seattle resident in a common float plane flight path, the piston engines can be quite loud. You can hear them inside with windows/doors closed and moderate household noises (like a shower or washing machine).