8 ms·

Amazing that the only thing you hear is the wind rustling by. Silent planes would be welcomed by many people living in densely populated cities with high air t

Amazing that the only thing you hear is the wind rustling by. Silent planes would be welcomed by many people living in densely populated cities with high air traffic. They're almost giving away apartments near Pearson Airport in Toronto, for example. The price per square foot in that area is ~10x lower than the rest of the city and for good reason. (You are constantly bombarded by the sound of jet engines passing by).

dmitrygr 6y ago
I love the sound of airplanes and all things airplane related. I think you may have just given me a great tip as to where to buy real estate. Thanks!
- deleted 6y ago
  [deleted]
- perl4ever 6y ago
  For all that you read about people complaining about airplane noise, I grew up only a mile or two from an airport and never thought about it nor do I remember anyone else complaining. But one of my recurring dreams/nightmares for most of my life is of watching a plane overhead and realizing at first something is wrong and then that it's going to crash in the back yard.
jeffbee 6y ago
Considering the rate at which the general aviation fleet turns over (~none in ~forever), and that the typical Cessna is flying around with a World War 2 engine or its closely related descendant, I predict that it will be roughly infinity years before people who live at the ends of airports stop cursing the noises. Of course, if they just outlaw 100LL avgas and pass some noise regulations the problem will solve itself.
- perl4ever 6y ago
  I was never clear on why leaded avgas wasn't banned long ago. I know I've run across information on the internet about aircraft engines that can run on unleaded.
  - NikolaeVarius 6y ago
    They're working on it. Can't ban it since many airplanes still require it.
    - amluto 6y ago
      I’m not entirely sure I buy this argument. Ban it effective on a fixed date in a few years and introduce a favorable regulatory regime to help with replacements. If some planes won’t be able to fly, so be it. Alternatively, introduce a Pigouvian tax: charge an obscene and increasing amount to burn leaded fuel. This is kind of like the regulations that permit grossly polluting old collectible cars to operate. Sure, they have history, but that’s not a sufficient excuse to allow them to operate unmodified near other people.
      - dpe82 6y ago
        Most piston engine aircraft in the country require, by regulation, 100LL. Oil companies and the FAA have been working for years to develop a replacement and came very close a couple years ago, but since the FAA strongly favors safety and reliability over almost any other consideration it takes a very long time to collect enough data to have confidence a potential replacement is truly equivalent. We have ~80 years of safety data for 100LL. Generally speaking, airports are reluctant to spend money on a second set of tanks, pumps, etc. required during a transition period; though some have - particularly in the midwest where there are a lot of less regulated homebuilt aircraft that can burn alternative fuels. A lot of pilots would love to burn something else. 100LL is relatively nasty and builds up in engines, shortening their life. It's even actively discouraged to burn 100LL in some more modern small aircraft engines like the Rotax 912 and pilots like myself who run that engine look for non-leaded fuel whenever practical because it's healthier for the engine. But well maintained aircraft last just about forever and the legacy fleet is absolutely enormous.
- unchocked 6y ago
  Those people can curse all they want, but the airports predate their homeownership.
  - throwaway0a5e 6y ago
    As much of a dick move as it is, it's not uncommon for homeowners to band together and work through local government to take down sources of noise that long predate them. When the source is a small airport or a local racetrack they often win.
    - jeffbee 6y ago
      The date the airport was built is nor always important. People in my area are upset because FAA nextgen approaches always fly precisely over the same guy's house every time, where they used to be a bit more scattered. Now the Oakland airport was built in 1927 and most of these houses date from the 1940s, but air travel has increased a lot on the intervening decades.
      - redis_mlc 6y ago
        You should not be able to hear a small plane at idle on landing approach, and VFR final approaches are not charted (can substantially vary in ground track.) So talk to a local FBO owner and work out an alternate landing for that "same guy's house." Source: commercially-rated airplane pilot.
        jeffbee 6y ago
        The angry neighbor club isn't upset about GA on approach, they're mad because the new WNDSR TWO arrival into OAK flies a tight corridor right along the ridgeline where people live in the Oakland hills. Here's the flight that most recently flew it: https://flightaware.com/live/flight/SWA743/history/20200531/0135Z/KPDX/KOAK https://flightaware.com/live/flight/SWA743/history/20200531/... That's all got nothing to do with why GA is irritating. GA is irritating because their little mosquitoes are low and slow and have piston engine sounds and their pilots have a tendency to loiter.
- briandear 6y ago
  Or maybe people could stop buying houses next to an airport that has been around for 80 years and arriving surprised that people fly airplanes around airports.
- catalogia 6y ago
  The typical non-electric Cessna Grand Caravan doesn't use avgas (they have turboprop engines), so outlawing leaded wouldn't ground them.
- dehrmann 6y ago
  Is the slow turnover because you don't have the same fatigue because the cabin isn't pressurized, older Cessnas are already decent, airframes haven't gotten that much better, and it's pretty easy to add modern Garmin avionics to an old plane?
sokoloff 6y ago
Props still make significant noise, especially at takeoff RPM. A friend of mine owned a house under the approach path to a medium-volume reliever airport (KBED). All of the piston airplanes that flew overhead were perfectly pleasant (at least to me), but the jets were notably more annoying. Carrying more power/noise, more speed, and more disturbance to stay flying while dirtied up, the difference was night and day. I suspect the PT-6 powered C208 would already fall on the “not so annoying” side of that spectrum (closer to the piston props than the turbojets’ noise profile), so changing fuel might not provide that much relief to those who bought houses near airports.
- inamberclad 6y ago
  I have a theory that we'll be able to reduce the RPM and increase the torque of these engines, versus conventional gas turbines and piston engines, thereby reducing the tip speed of the blades
  - sokoloff 6y ago
    Maybe. The PT6A already has a gearbox, so the engineers are presumably able to choose a reduction ratio and prop RPM quite independently of the gas and power generator rotational speeds. (There are still torque limits in the gearbox output, though it seems the same constraints would face an electric motor.)
    - dpe82 6y ago
      In most planes, pilots are already able to chose their propeller RPM somewhat independently of torque by varying the pitch of the propeller. However, pilots typically optimize for rate of climb and not noise in order to get out of the low altitude / low airspeed danger zone as quickly as possible.
      - sokoloff 6y ago
        Yes. What GP is talking about though is changing the range of speeds available for pilot selection by changing the prop length, airfoil, maybe number of blades, and other design parameters. IOW, the design elements, not so much the operational element. Similar to how the C421 cruises at 1800-1900 prop RPM to give a(n eerily) quieter cabin.
AdrianB1 6y ago
Not true; the only aircraft that does what you describe is a glider. Any propeller will generate a lot of noise, the tips of the blades get close to the sound barrier. Disclaimer: pilot here, I did fly gliders and I fly propeller planes regularly.
- m4rtink 6y ago
  Well, even in a glider all the air moving by does quite some hissing, so its not completely silent (judging from the two flights I took as a passenger in a Blanik and Super Blanik respectively). Still much quieter than a small prop aircraft & you can talk with the pilot just fine. On the other hand from the ground - yeah, a glider is pretty much silent. You might sometimes hear some rather earie whistling from some types when they are directly above, but thats it.
  - AdrianB1 6y ago
    He said the wind is the only thing you hear. Yes, in a glider you hear the air moving, but adding a propeller adds a huge amount of noise over that base sound.
WalterBright 6y ago
That price differential can make a lot of soundproofing worthwhile.

dmitrygr 6y ago

I love the sound of airplanes and all things airplane related. I think you may have just given me a great tip as to where to buy real estate. Thanks!

deleted 6y ago
[deleted]
perl4ever 6y ago
For all that you read about people complaining about airplane noise, I grew up only a mile or two from an airport and never thought about it nor do I remember anyone else complaining. But one of my recurring dreams/nightmares for most of my life is of watching a plane overhead and realizing at first something is wrong and then that it's going to crash in the back yard.

jeffbee 6y ago

Considering the rate at which the general aviation fleet turns over (~none in ~forever), and that the typical Cessna is flying around with a World War 2 engine or its closely related descendant, I predict that it will be roughly infinity years before people who live at the ends of airports stop cursing the noises. Of course, if they just outlaw 100LL avgas and pass some noise regulations the problem will solve itself.

perl4ever 6y ago
I was never clear on why leaded avgas wasn't banned long ago. I know I've run across information on the internet about aircraft engines that can run on unleaded.
- NikolaeVarius 6y ago
  They're working on it. Can't ban it since many airplanes still require it.
  - amluto 6y ago
    I’m not entirely sure I buy this argument. Ban it effective on a fixed date in a few years and introduce a favorable regulatory regime to help with replacements. If some planes won’t be able to fly, so be it. Alternatively, introduce a Pigouvian tax: charge an obscene and increasing amount to burn leaded fuel. This is kind of like the regulations that permit grossly polluting old collectible cars to operate. Sure, they have history, but that’s not a sufficient excuse to allow them to operate unmodified near other people.
    - dpe82 6y ago
      Most piston engine aircraft in the country require, by regulation, 100LL. Oil companies and the FAA have been working for years to develop a replacement and came very close a couple years ago, but since the FAA strongly favors safety and reliability over almost any other consideration it takes a very long time to collect enough data to have confidence a potential replacement is truly equivalent. We have ~80 years of safety data for 100LL. Generally speaking, airports are reluctant to spend money on a second set of tanks, pumps, etc. required during a transition period; though some have - particularly in the midwest where there are a lot of less regulated homebuilt aircraft that can burn alternative fuels. A lot of pilots would love to burn something else. 100LL is relatively nasty and builds up in engines, shortening their life. It's even actively discouraged to burn 100LL in some more modern small aircraft engines like the Rotax 912 and pilots like myself who run that engine look for non-leaded fuel whenever practical because it's healthier for the engine. But well maintained aircraft last just about forever and the legacy fleet is absolutely enormous.
unchocked 6y ago
Those people can curse all they want, but the airports predate their homeownership.
- throwaway0a5e 6y ago
  As much of a dick move as it is, it's not uncommon for homeowners to band together and work through local government to take down sources of noise that long predate them. When the source is a small airport or a local racetrack they often win.
  - jeffbee 6y ago
    The date the airport was built is nor always important. People in my area are upset because FAA nextgen approaches always fly precisely over the same guy's house every time, where they used to be a bit more scattered. Now the Oakland airport was built in 1927 and most of these houses date from the 1940s, but air travel has increased a lot on the intervening decades.
    - redis_mlc 6y ago
      You should not be able to hear a small plane at idle on landing approach, and VFR final approaches are not charted (can substantially vary in ground track.) So talk to a local FBO owner and work out an alternate landing for that "same guy's house." Source: commercially-rated airplane pilot.
      - jeffbee 6y ago
        The angry neighbor club isn't upset about GA on approach, they're mad because the new WNDSR TWO arrival into OAK flies a tight corridor right along the ridgeline where people live in the Oakland hills. Here's the flight that most recently flew it: https://flightaware.com/live/flight/SWA743/history/20200531/0135Z/KPDX/KOAK https://flightaware.com/live/flight/SWA743/history/20200531/... That's all got nothing to do with why GA is irritating. GA is irritating because their little mosquitoes are low and slow and have piston engine sounds and their pilots have a tendency to loiter.
briandear 6y ago
Or maybe people could stop buying houses next to an airport that has been around for 80 years and arriving surprised that people fly airplanes around airports.
catalogia 6y ago
The typical non-electric Cessna Grand Caravan doesn't use avgas (they have turboprop engines), so outlawing leaded wouldn't ground them.
dehrmann 6y ago
Is the slow turnover because you don't have the same fatigue because the cabin isn't pressurized, older Cessnas are already decent, airframes haven't gotten that much better, and it's pretty easy to add modern Garmin avionics to an old plane?

sokoloff 6y ago

Props still make significant noise, especially at takeoff RPM. A friend of mine owned a house under the approach path to a medium-volume reliever airport (KBED). All of the piston airplanes that flew overhead were perfectly pleasant (at least to me), but the jets were notably more annoying. Carrying more power/noise, more speed, and more disturbance to stay flying while dirtied up, the difference was night and day. I suspect the PT-6 powered C208 would already fall on the “not so annoying” side of that spectrum (closer to the piston props than the turbojets’ noise profile), so changing fuel might not provide that much relief to those who bought houses near airports.

inamberclad 6y ago
I have a theory that we'll be able to reduce the RPM and increase the torque of these engines, versus conventional gas turbines and piston engines, thereby reducing the tip speed of the blades
- sokoloff 6y ago
  Maybe. The PT6A already has a gearbox, so the engineers are presumably able to choose a reduction ratio and prop RPM quite independently of the gas and power generator rotational speeds. (There are still torque limits in the gearbox output, though it seems the same constraints would face an electric motor.)
  - dpe82 6y ago
    In most planes, pilots are already able to chose their propeller RPM somewhat independently of torque by varying the pitch of the propeller. However, pilots typically optimize for rate of climb and not noise in order to get out of the low altitude / low airspeed danger zone as quickly as possible.
    - sokoloff 6y ago
      Yes. What GP is talking about though is changing the range of speeds available for pilot selection by changing the prop length, airfoil, maybe number of blades, and other design parameters. IOW, the design elements, not so much the operational element. Similar to how the C421 cruises at 1800-1900 prop RPM to give a(n eerily) quieter cabin.

AdrianB1 6y ago

Not true; the only aircraft that does what you describe is a glider. Any propeller will generate a lot of noise, the tips of the blades get close to the sound barrier. Disclaimer: pilot here, I did fly gliders and I fly propeller planes regularly.

m4rtink 6y ago
Well, even in a glider all the air moving by does quite some hissing, so its not completely silent (judging from the two flights I took as a passenger in a Blanik and Super Blanik respectively). Still much quieter than a small prop aircraft & you can talk with the pilot just fine. On the other hand from the ground - yeah, a glider is pretty much silent. You might sometimes hear some rather earie whistling from some types when they are directly above, but thats it.
- AdrianB1 6y ago
  He said the wind is the only thing you hear. Yes, in a glider you hear the air moving, but adding a propeller adds a huge amount of noise over that base sound.

WalterBright 6y ago

That price differential can make a lot of soundproofing worthwhile.