Aviation: Environmental Impact

[EconomyClass]

Most types of technology for travel and freight are going through a metamorphosis in the interests of lowering the impact on the environment. I wonder about aviation, especially about general aviation. The virtue of commercial aviation is that costs have forced the companies to up the load factor to the point where someone actually broached the subject of vertical tickets (so far, not a serious possibility, but who knows?) My city has hybrid buses. There's lots of discussion about which freight option is the best in terms of minimal combusted materials.

But general aviation? Is it stuck in the 50's where "cruising" was another popular form of recreation? I mean, the population of owners probably tilts toward the rich, anyway. John Travolta owns and flies some Boeing airliner (Hefner envy?) So its doubtful that costs are gonna take private planes out of the sky. What will suffice to push these owners toward technology that is good for the earth?

[rohank4284]

Most types of technology for travel and freight are going through a metamorphosis in the interests of lowering the impact on the environment. I wonder about aviation, especially about general aviation. The virtue of commercial aviation is that costs have forced the companies to up the load factor to the point where someone actually broached the subject of vertical tickets (so far, not a serious possibility, but who knows?) My city has hybrid buses. There's lots of discussion about which freight option is the best in terms of minimal combusted materials.

But general aviation? Is it stuck in the 50's where "cruising" was another popular form of recreation? I mean, the population of owners probably tilts toward the rich, anyway. John Travolta owns and flies some Boeing airliner (Hefner envy?) So its doubtful that costs are gonna take private planes out of the sky. What will suffice to push these owners toward technology that is good for the earth?

Aviation is obviously not the best thing for the enviornment. Commercial aircraft do put a scignificant amount of C02 into the air and create noise disturbances. However, in the past decade newer generation commercial aircraft like the Boeing 777, Airbus A340-500/600, 737NG, and the Airbus A320 series have dramatically lower emission and noise levels than the previous generation of aircraft. The Boeing 787, Airbus A380, and A350 will be significantly quieter and more efficient than today's planes and many airlines are starting to use bio-diesel for airport equipment. http://www.latimes.com/business/la-f...,1161291.story

Boeing 777: (environmental data) http://www.boeing.com/commercial/777...ron/index.html

Boeing 787: is expected to be about 20% than a comparable Boeing 767-300/400 aircraft and the engines are at least 8% more efficient than the current gen engines being used on similarly sized aircraft.

Airbus A380: http://www.airbus.com/en/aircraftfam.../index2.html#3 Fuel burn is 12% less than the Boeing 747-400 and is significantly quieter.

In addition, many airlines now are more efficiently using their fleets (you will rarely see a Boeing 747-400 doing a routine domestic hop), partially due to the economic climate, which yields higher load factors and less CO2 and nitrate emission per mile. Unofficially, some studies claim that one passenger flying on a commercial jet puts out around 1.25 to 2x more emissions than the per passenger totals of a dual-occupant car per mile. I'm looking for more concrete data on that right now.

http://www.geocities.com/dtmcbride/t...plane-car.html (plane vs. car vs. train in emissions)

a more recent study: http://www.sightline.org/research/en...r_travel_aug04

As for noise, the best study of airline noise I found was this one: http://www.faa.gov/about/office_org/.../noise_levels/

The Boeing 707 is a very rare aircraft in today's skies, thus much of the fuel-inefficiency and the environmental impact of the few 707s flying around is easily mitigated by the vast technical efficiency improvements of today's current gen aircraft. Aircraft aren't the best thing for the environment, their purpose is to get people from point A to point B as quickly as possible, but current generation aircraft are much more efficient and do a lot less damage to the environment than previous generations of aircraft.

Regards,

Rohan

[brianw999]

Rohan said..

Commercial aircraft do put a scignificant amount of C02 into the air

Aviation is reckoned to account for around 2% of so-called global warming gases and is one of the most looked at and criticised commercial enterprises when global warming and pollution is being discussed.

Compare that to the major worldwide land based industrial empires ( reminder..the ones that politicians have a vested interest in $$$$$$$$ŁŁŁŁŁŁŁŁŁ !!!!!) that pump out millions of tons of CO2 daily, but which remain largely unreported, and by far exceed the "global poisoning" that is attributed to aviation.

Such industries far exceed aviations' 2% input but little is done about them.

As an aside......
At the moment it's 27degC in my part of the UK. Someone said to me yesterday..."Shit it's hot...it's all down to global warming"

Is it (expletive deleted) hell as like...it's called "Summertime" !!

[brianw999]

On the subject of noise....

I recall some time ago a group of NIMBY's ( Not In My BackYard ! ) moaning about a neighbour who occasionally flew his helicopter in and out of his large back garden and the "unbearable noise" that it caused.

Chief NIMBY spokesman was being interviewed by a TV news reporter for a slot on the evening news and was standing in his back garden with his back to the neighbours' landing pad. He chundered on about disrespect for neighbours need for quiet, disturbing a peaceful countryside, unbearable noise where he was standing, television sound being drowned out etc. etc.

The reporter was doing his best not to laugh aloud because......

....the neighbour took off, landed, took off and landed again behind chief NIMBY who never heard a thing.

The application by the NIMBY's to suppress the aviation use of the helicopter owning neighbour was rightfully canned by the courts when they saw the video footage.

[C-FMWQ]

Aviation is obviously not the best thing for the enviornment. Commercial aircraft do put a scignificant amount of C02 into the air and create noise disturbances.

This is a common thought of many people that Airplanes create huge problems for C02 emissions.

Only about 2% of all emissions C02 emissions are from Airplanes. It really annoys me when people say that planes cause all of this global warming then they drive Hummers or other cars that create huge emissions.

Though you are right Rohan, airplanes have gotten a whole lot more efficient in the past decades. Look at an airline like Air Canada, they had a fleet of 747-400M's, 767-200's and 767-300's, A32X's, and A340's.

They then realized that it would probably be more economical for them to have 777's so they bought those to get rid of the 747-400's and A340's as they are better on fuel and they also bought new A330's which are better on fuel. To get rid of the older A32X's Air Canada bought some Embraer 175's and 190's that are quite efficient. They now have a fairly new fleet of planes that are quite efficient compared to some airlines that still operate planes like the older variants of the 747 and some other planes.

The main problem I see is that most people have a certain perception that airplanes are the worst thing to have on the entire earth for pollution, without knowing the actual emissions.

Nehal

[rohank4284]

Rohan said..


Aviation is reckoned to account for around 2% of so-called global warming gases and is one of the most looked at and criticized commercial enterprises when global warming and pollution is being discussed.

Compare that to the major worldwide land based industrial empires ( reminder..the ones that politicians have a vested interest in $$$$$$$$ŁŁŁŁŁŁŁŁŁ !!!!!) that pump out millions of tons of CO2 daily, but which remain largely unreported, and by far exceed the "global poisoning" that is attributed to aviation.

Such industries far exceed aviations' 2% input but little is done about them.

As an aside......
At the moment it's 27degC in my part of the UK. Someone said to me yesterday..."Shit it's hot...it's all down to global warming"

Is it (expletive deleted) hell as like...it's called "Summertime" !!

Very true Brian, however, I never meant that airplanes are an extreme or major source of pollutants. I viewed a couple of studies and the percentage of global warming gasses released by planes was around 3-5%. Compare this to cars, which account for over 50% of typical global warming gasses! I think scignificant was a strong word for what I was trying to describe. Airplanes do contribute to global warming gasses, but not at nearly the rate or percentage people think they are and today's planes are a great deal more "environmentally friendly" than previous generation planes.

Your friend is being pretty ridiculous if he's claiming 27C is mind-numbingly hot. I can't imagine what he would say if we sent him to New Delhi in the middle of summer (37-45C days, with 28-34C lows and 100% humidity are common) or heck even send him to Denver (we average about 28-34C in summer) and we'll see if he doesn't change his mind!

As for noise, yep, today's planes are much, much quieter than even 10-15 years ago

On the subject of noise....

I recall some time ago a group of NIMBY's ( Not In My BackYard ! ) moaning about a neighbour who occasionally flew his helicopter in and out of his large back garden and the "unbearable noise" that it caused.

Chief NIMBY spokesman was being interviewed by a TV news reporter for a slot on the evening news and was standing in his back garden with his back to the neighbours' landing pad. He chundered on about disrespect for neighbours need for quiet, disturbing a peaceful countryside, unbearable noise where he was standing, television sound being drowned out etc. etc.

The reporter was doing his best not to laugh aloud because......

....the neighbour took off, landed, took off and landed again behind chief NIMBY who never heard a thing.

The application by the NIMBY's to suppress the aviation use of the helicopter owning neighbour was rightfully canned by the courts when they saw the video footage.

Wow, that's a very funny story Brian. I still think jet airplanes could be considerably quieter though. For instance, a Boeing 777 typically takes off with a noise level of 88-94 dB and approaches at about 97.2db, an A340-500/600 takes off at around 90-96 db and approaches at about 99db. The new Boeing 737NG takes off around 81db and approaches at about 91db. Anything above 80db is considered uncomfortable to human ears and prolonged exposure can cause mild to moderate hearing loss. Today's planes are similar in noise to trains. Modern day helicopters ,on the other hand, are extremely quiet, as you stated above.

The Airbus A380 is very quiet for a such a huge plane and I look forward to seeing how quiet the new Boeing 787 or Airbus A350 are.

here's a good study: http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/0c7e20b642c8f8fc86256e3700761828/$FILE/AC%2036-1H%20appendix%201.pdf

This is a common thought of many people that Airplanes create huge problems for C02 emissions.

Only about 2% of all emissions C02 emissions are from Airplanes. It really annoys me when people say that planes cause all of this global warming then they drive Hummers or other cars that create huge emissions.

Though you are right Rohan, airplanes have gotten a whole lot more efficient in the past decades. Look at an airline like Air Canada, they had a fleet of 747-400M's, 767-200's and 767-300's, A32X's, and A340's.

They then realized that it would probably be more economical for them to have 777's so they bought those to get rid of the 747-400's and A340's as they are better on fuel and they also bought new A330's which are better on fuel. To get rid of the older A32X's Air Canada bought some Embraer 175's and 190's that are quite efficient. They now have a fairly new fleet of planes that are quite efficient compared to some airlines that still operate planes like the older variants of the 747 and some other planes.

The main problem I see is that most people have a certain perception that airplanes are the worst thing to have on the entire earth for pollution, without knowing the actual emissions.

Nehal

Yep, I agree people's perceptions against airplanes are extremely strong, but in reality your nice little car or the CO2 generated from powering your house release multitudes more CO2 than an Airplane. I do think airplanes do have a slight effect on the environment because their nitrate % is a little bit higher (5-10%) than the CO2 percentage (2-5%). If airplanes follow the current trend of improved efficiency and better engines which produce cleaner emissions, we should concentrate far more of our efforts on getting rid of gas guzzling cars and making car emissions cleaner.

[SYDCBRWOD]

Wow, that's a very funny story Brian. I still think jet airplanes could be considerably quieter though. For instance, a Boeing 777 typically takes off with a noise level of 88-94 dB and approaches at about 97.2db, an A340-500/600 takes off at around 90-96 db and approaches at about 99db. The new Boeing 737NG takes off around 81db and approaches at about 91db. Anything above 80db is considered uncomfortable to human ears and prolonged exposure can cause mild to moderate hearing loss. Today's planes are similar in noise to trains. Modern day helicopters ,on the other hand, are extremely quiet, as you stated above.

The figures above are stating that most of the aircraft are several magnitudes quieter when they take off than when they land. Obviously, this depends very much on the flight profile, but I cannot see how a heavily loaded aircraft makes less noise using take off thrust settings than it does when throttled back for landing (is using reverse thrust massively noisier?).

One more point that has not been adressed is the matter of where the emissions are deposited. A Hummer in city traffic could be less polluting that an airliner in cruise due to the fact that the emissions from the jet are up much higher. I recall reading something about the Nitrous emissions (?) forming far nastier compounds because of the altitude and temperature.

Ah, here's two bits of info:

http://news.nationalgeographic.com/news/2006/06/060614-contrails.html

http://en.wikipedia.org/wiki/Aviation_and_the_environment

So its not all about relative emissions per passenger seat kilometer - cars versus planes, because aircraft operate in (obviously) a very different part of the atmosphere.

[rohank4284]

The figures above are stating that most of the aircraft are several magnitudes quieter when they take off than when they land. Obviously, this depends very much on the flight profile, but I cannot see how a heavily loaded aircraft makes less noise using take off thrust settings than it does when throttled back for landing (is using reverse thrust massively noisier?).

One more point that has not been addressed is the matter of where the emissions are deposited. A Hummer in city traffic could be less polluting that an airliner in cruise due to the fact that the emissions from the jet are up much higher. I recall reading something about the Nitrous emissions (?) forming far nastier compounds because of the altitude and temperature.

Ah, here's two bits of info:

http://news.nationalgeographic.com/news/2006/06/060614-contrails.html

http://en.wikipedia.org/wiki/Aviation_and_the_environment

So its not all about relative emissions per passenger seat kilometer - cars versus planes, because aircraft operate in (obviously) a very different part of the atmosphere.

Wow, you have some good points and interesting websites. I too was surprised when I read that most commercial jets are actually louder on approach than take-off, so the numbers aren't fake. They're actually taken from a study on aircraft noise conducted by the FAA on typical noise levels the study is found here: http://www.airweb.faa.gov/Regulatory...256E3700761828

and here http://www.faa.gov/about/office_org/.../noise_levels/

The study doesn't include the noise on landing it was only taking about noise on approach, so I highly doubt the thrust reversers on the engines played a role. You're correct in saying that flight routing and weather do play scignificant roles in determining perceived aircraft noise.

I looked through the study again and yes, you're correct when the aircraft is heavier the difference between the db levels on take-off and approach is much less. For instance, on one Boeing 777 with a GE90-94B (94,000 lbs. of thrust) with a take-off weight of 580,000 lbs. had a take-off noise level of 87.5db and an approach noise level of 97.9. A considerable heavier Boeing 777-200ER with a take-off weight of 656,000 lbs. with similar GE90-94B had a 91.1 db take-off noise rating and a 98.3 db approach noise rating.

From what I could find, aircraft noise is typically higher on approach than take-off because of the extra drag created by using a high or full flap setting and from the extra drag created by the landing gear, thus a higher thrust setting usually around 55-65% N1 is needed by many commercial jet airliners, compared to the thrust idle to 40%N1 descent thrust. In addition, the flaps and the landing gear disrupt airflow, so they themselves create more noise. In addition, the aircraft often approaches the airport at a slower speed and is decreasing in altitude, so pitch and frequency often increases steadily until the time of landing.

On take-off a much lower flap setting is used, so there less drag, and most of the time the landing gear is retracted as soon as a positive rate of climb is established, so the disruption of airflow is less. You're correct take-off thrust is much higher than approach thrust, as many planes take-off with about 82-99% N1. Unlike approach, the extra noise created from the flaps and landing gear isn't nearly as much because of the lower flap setting and quick retention of the landing gear. In addition, the plane is climbing rapidly at a high speed. Thus, the pitch and frequency of the noise quickly drop and this may be reflected in aircraft noise measurements.

In fact, when Boeing made several changes to a Boeing 777-300ER in their QTD2 test in August 2005, one of the major changes was to cover the landing gear with a shield to reduce drag and noise from air flowing over the landing gear.

Here's the link to a Seattle Post Intelligencer article on that test: http://www.seattlepi.com/business/23...uietjet11.html



You make good points about aircraft pollution being more direct and possibly more harmful because it's inserted directly into higher altitude air. I talked about higher nitrate emissions by aircraft in my above post.

However, I believe that people need to realize that there are far more harmful things than aircraft, which regularly pollute the environment. Heck even powering your home, could easily eclipse the amount of pollution produced by commercial jets. Cars, factories (though finally some stricter regulations have been passed), and the use of coal power plants all produce high levels of CO2 and should be looked at as carefully or more carefully than the environmental factors of airplanes. One thing that bothers me about aircraft, is their relatively higher nitrate emissions, today's current-gen. aircraft have cut down dramatically on nitrate emissions and hopefully they'll be able to further cut down on those in the future. Aircraft designers have made planes dramatically quieter and more efficient in the past 20 years and the next generation of aircraft will only continue that trend.

Rohan

[JordanD]

But general aviation? Is it stuck in the 50's where "cruising" was another popular form of recreation? I mean, the population of owners probably tilts toward the rich, anyway. John Travolta owns and flies some Boeing airliner (Hefner envy?) So its doubtful that costs are gonna take private planes out of the sky. What will suffice to push these owners toward technology that is good for the earth?

What I seem to be getting here is that since GA flying is something apparently only rich people do that we should put a stop to it? The fact is that GA doesn't have enough of an impact to really necessitate drastic measures. Why not worry about factories and ocean liners?

And yes, I often times "cruise" for fun. I think I'll enjoy the limited amount of times I have.

[brianw999]

=rohank4284;525682]......Your friend is being pretty ridiculous if he's claiming 27C is mind-numbingly hot......

You have to remember that this is the UK. We regard anything above 25C as hot and it also gets pretty humid as well.

I worked in Saudi Arabia regularly in temperatures exceeding 40C, but was more comfortable there than in the UK.

[ATFS_Crash]

Most types of technology for travel and freight are going through a metamorphosis in the interests of lowering the impact on the environment. I wonder about aviation, especially about general aviation…. But general aviation? Is it stuck in the 50's where "cruising" was another popular form of recreation?…What will suffice to push these owners toward technology that is good for the earth?

I think for a large part you’re looking at things backwards. Much of the advances that the automotive industry has made at making their vehicles more fuel-efficient and have less of an environmental impact is because they are copying (benefiting) from strides made largely from aviation technology. Fuel injection, electronic ignition, etc… largely got its start in aviation to gain more power, and to get more power from a smaller lighter power plant, and to be more fuel-efficient ( thusly saving weight and extending range). Composites largely got its start in the aviation industry; it’s now becoming more popular in the automobile industry.

When I was a kid back in the 60s my uncle used to make trips across the country in a light aircraft; he was often criticized for his extravagance. Yet the truth of the matter in many ways the truth was quite on the contrary of what shallow minded peoples first impressions were. He said though the costs of operating a light aircraft was rather high; it was cheaper for him in the long run for the type of travel he was doing. He said even though the aircraft consumed fuel at a higher rate it was offset because aircraft could travel faster and more directly. He said the fuel costs were less for his airplane, then it was for his car traveling to the same destinations. He said even though that the operating costs for his airplane was higher than his car; in the overall picture it was cheaper to do his type of travel by airplane; because the car required more fuel to get to the same destinations; the travel was slower by car so by car it cost more for food and lodging etc….

I also had a friend that jokingly called himself and we jokingly called him a “drug pusher“. He was a legitimate type of drug pusher; a pharmaceutical salesman. You know, the type of guy that you get mad at when you go to visit your doctor because you have to wait an hour before your name is about to be called, then the doctor stop seeing patients for a while to talk to a pharmaceutical salesman; so you can’t help but feel that the pharmaceutical salesman is partly to blame for your long wait.

My drug pusher friend found his niche by taking remote territories in his pharmaceutical company that other salesman refused to take because the costs and time made the territories low profit or a profit loss when traveling by car. What he would do is fly to remote regions; and pull a motorized bicycle out of the back of his airplane and ride his motorized bicycle to make his calls on the doctors. By using this method he was able to turn sales territory that were low profit or profit loss into territories that were profitable enough to subsidize his hobby “aviation” and he was able to clear enough profit to be middle class and support a small family and have a small house. He was able to cover the same amount of sales territory as about five salesmen. Another advantage of using an aircraft for his type of work is that he was able to be home with his family almost every night, whereas if he did it by car he would be spending a lot more time on the road.

Regrettably thanks to government regulation/bureaucracy and greedy over litigative lawyers; I think this type of aviation has become much more expensive; thusly doing business this this way is largely a thing of the past from what I understand. So from what I understand thanks to government regulation/bureaucracy and greedy over litigative lawyers it’s harder to make a living in this type of business and they use more fuel in this niche now.

I think the people that just “cruise” aircraft are in the vast minority. There are many pilots that like to have the mindset that they are just going on a “pleasure cruise” but that is often just an attitude to make a task more pleasurable/enjoyable. If you have to fly to get to a destination or to meet some requirements; I don’t see any problem with making it pleasurable and having the attitude that it is a “pleasure cruise”. I think as long as people don’t get carried away with that attitude and let it be a distraction it could actually be a benefit because it can keep a pilot’s mind positive and alert.

Of course another aspect of your criticism is that I think it is politically correct liberal fascism. Part of our Declaration of independence, is the “pursuit of happiness“. I feel that you and your type are trying to stifle (reasonable freedoms) reasonable pursuit of happiness; by advancing prejudice against the aviation industry and community. I feel that you are advocating prejudice/hatemongering/channelized thinking. I feel that in a free country; if a private pilot wants to go up for a pleasure cruise/joyride then they should be allowed the freedom; within reason.

I suppose if a pilot needed a flight to keep his currency or meet some other requirement or do some other task and he offered you a joy ride; that you would think of it only as a joy ride/cruising. For the passenger perhaps it’s entirely a joyride/cruise; but for the pilot there often is a bigger more serious purpose and he is probably just trying to make a required task to be more enjoyable. Regrettably there are people that want life to be devoid of joy; killjoys.


I vaguely seem to remember some statistics that someone posted here that riding on a commercial airliner to a far away destination used less fuel than traveling by car. I suspect in many cases traveling by commercial airline would have less of an environmental impact (including less pollution) then driving by car.

[brianw999]

ATFS Crash said....

I also had a friend that jokingly called himself and we jokingly called him a “drug pusher“. He was a legitimate type of drug pusher; a pharmaceutical salesman. You know, the type of guy that you get mad at when you go to visit your doctor because you have to wait an hour before your name is about to be called, then the doctor stop seeing patients for a while to talk to a pharmaceutical salesman; so you can’t help but feel that the pharmaceutical salesman is partly to blame for your long wait.

And why not ?
Where the hell am I supposed to get my free pens, tourniquets, stethoscope, pen torches, next years diary and a free lunch buffet from if it's not from "Drug Pushers" !!!

Next you'll be telling me that patients are important to the health service.

[ATFS_Crash]

And why not ?
Where the hell am I supposed to get my free pens, tourniquets, stethoscope, pen torches, next years diary and a free lunch buffet from if it's not from "Drug Pushers" !!!

Next you'll be telling me that patients are important to the health service.

He also told me at times he didn’t think people from the medical community were very bright. Often the doctors or staff would see him arrive to make his calls. He said often the doctors would expect the pharmaceutical salesman to treat lunch as part of a perk (have the salesman drive and pay for the lunch). My drug pusher ( pharmaceutical salesman) friend said the doctors would often ask him to drive to lunch; my drug pusher friend would often respond I will drive as long as you don’t mind riding on the back of my motorized bicycle. He said the doctors or medical staff would ask him where he lived or see the plates on his motorized bicycle and ask if he drove it here; he would always respond yes. This often baffled or amazed doctors and medical staff since his plates were often from hundreds of miles away from a different county or state. He said they almost always assumed he rode ALL the way. He said they hardly ever phrased their questions in the context of “did you ride ALL the way on the motorized bicycle”. So he often used it to yank their chain as a joke and as an icebreaker. He said a lot of them had a hard time understanding or believing that he flew most of the way in an airplane to only finish the final leg on a motorized bicycle he kept in the back of his airplane. He said sometimes he just let people believe that he rode all the way on his motorized bicycle. A pharmaceutical salesman with a briefcase full of samples and other perks strapped to his motorized bicycle…. He said it would crack him up because they would often ask him to drive them to lunch even after seeing him drive up on his motorized bicycle; evidently the doctors and medical staff became so involved in what they were doing and the conversation that they would forget that he was riding a motorized bicycle.

Sometimes the truth and the weird way people perceive things is the funniest thing.

[EconomyClass]

Regrettably there are people that want life to be devoid of joy; killjoys.

This is a giant leap of speculation. But its a familiar one. Anytime you mention that moderation might be wise, someone goes ballistic and accuses you of suggesting anhedonia. Some people like to drive 100 mph on the freeway.. If I say that's dubious, these people will say "Oh no, my god-given right to joy in life is being threatened". And I will suggest that those people who have self-discipline have occasional moments of pleasure, too. By the way, the Declaration of Independence is a political document for going to war in a country that had a majority against the war. The Constitution never mentions "pursuit of happiness" once. Check out the Bill of Rights. You won't find it.

As for "not worrying about factories or cars", of course we "fascists" worry about them. But that doesn't exclude attention for activities not needed to have economic survival. I'm part of a shade of opinion that says drug sales right now are eating UP the economy. They are about as helpful as casinoes. If all drug salesmen were chained to desks and had to use phones, the economy wouldn't suffer at all.

[P3_Super_Bee]

The figures above are stating that most of the aircraft are several magnitudes quieter when they take off than when they land. Obviously, this depends very much on the flight profile, but I cannot see how a heavily loaded aircraft makes less noise using take off thrust settings than it does when throttled back for landing (is using reverse thrust massively noisier?).

Quite a few places we travel to have no reverse rules in effect after dark.