Why is it that the roar of planes flying overhead at night is barely audible, but so loud during the

The actual reason is thisInternational Civil Aviation Organization(ICAO) and the Civil Aviation Administration of China (CAAC) for civil aircraft flying at nightFlight altitudeThere are clear regulations and restrictions, low air flow temperature at night, unstable air flow, and greater flight resistance than during the day! And the interference of ground lights and searchlights is relatively strong! Therefore, the planes that fly at night are flying high.

Therefore, the sound of the aircraft cannot be transmitted to the ground (the distance is too long, and the sound energy is attenuated), in fact, the aircraft flies relatively high during the day, but some military aircraft.

Flying relatively low, we often hear military aircraft, especially transport aircraft.

The sound of the countryside before 1980 in the last centuryThere was no machinery, except for the crowing of chickens and dogs, there was no noise in the space, and in the dead of night, I could faintly hear the hoofs of horses walking on the road two kilometers away from my houseAt that time, the sound of airplanes in the sky was very shocking! Even *** can hear a loud sound. Later, with the increase of machinery and the progress of science and technology, there was too much noise in space, and the sound attenuation system of the aircraft was perfected.

The noise of the aircraft is relatively low. If the airflow velocity is greater thanSpeed of sound, where the velocity of the gas downstream is greater than the propagation speed of the weak disturbance wave relative to the gasNot only can the disturbance not propagate against the current, but it is also restricted to propagate within a certain area. The propagation of weak perturbations in supersonic air currents is confined to a series of spherical tangent cones with point O as the apex, called the Mach cone, and the area outside the Mach cone is the "silent zone".

So sometimes we can't hear the plane until it flies over our heads. The aircraft is supposed to be flying at supersonic speed, in which case the speed of sound propagation is less than the speed of the aircraft, and the perturbation of the sound waves is confined to a Mach cone, the aircraft is located on top of the cone. By the time the sound reached the ground, the plane was already far away, so it was no longer visible when I looked up.

A few days ago on the fifth floor, I was watching TV when suddenly I heard a loud noise from the plane. I walked to the window and looked at it. I thought the plane would fall when it was noisy.

I think the weather was bad that day and the plane landed very low. Usually closing the windows still doesn't affect other people. The noise of the aircraft mainly comes from the take-off and landing phases of the aircraft, because in these two stages the altitude of the aircraft is low and the power of the engine is high, so the noise is also high.

However, once the aircraft flies to the cruising phase, its altitude is usually relatively high, at which point we can barely hear any noise. Therefore, I would like to talk about flying overhead during the take-off phase, or military aircraft, especially ***. Large airliners need to turn on their internal landing lights when flying below 10,000 feet (to prevent birds), and they need to turn on navigation lights, support points, and crash lights when flying in normal times.

It's hard to see these lights during the day. But at night when visibility is good, it's easy to find planes with lights in the sky.

Secondly, many airports now have noise cancellation procedures at night. Pilots can reduce aircraft noise through specific methods. In order to keep the people around the airport restful, there are many flights departing during the day, but not many flights departing at night.

Many of these are long-haul flights. Civil aircraft make a lot of noise only when they take off, because the engines need to run at maximum power.

When landing, the engine speed is very low, the plane is basically taxiing, and naturally there is not much noise. There is also a supersonic aircraft, which is very fast, but it also makes very little noise. Supersonic flight is inaudible from behind, and sounds above 10,000 Hz in front are inaudible, as redshift is similar to 10,000 Hz to 20,000 Hz, so it is inaudible.

Instead, some infrasound waves can be heard.

Why is it that flights flying at night are barely audible, but the roar during the day is so loud.

The main reason is that the temperature of the low air flow at night is low, the air flow is unstable, the flight resistance is greater than that during the day, and the interference of ground lights and searchlights is relatively strong, so it is difficult to hear the sound at night.

This is because the decibel lowering device is used at night so as not to disturb people's rest.

The loud sound of the aircraft is generally when the aircraft is rising or sprinting sharply, or when flying at supersonic speeds, there will be a loud sound.

Because the plane at night needs to reduce the speed of its flight, it is impossible to hear the roar.

That's because when an airplane flies at night, it pays attention to its noise, frequency, and decibels.

It should be that the plane has noise reduction measures during the night flight, and the work of people during the day has little impact.

In fact, the sound of the plane is the same, but there are many people during the day, and the small sound of the plane is automatically ignored.

It's not the difference between day and night, it's the difference between how close you are.

Because the plane is more dragged at night, it is almost impossible to hear the sound.

Maybe it's because the planes fly relatively low during the day.

There could be several reasons why there is the roar of planes outside in the middle of the night:

1.It is surrounded by a high-incidence area of lightning, and when the positive and negative charges in the clouds collide, a loud sound will occur, commonly known as thunder. This natural phenomenon has nothing to do with airplanes, but it can be caused by thunderstorms that produce the roar of airplanes when flying.

2.The quality of the sky is better at night, and the aircraft chooses to conduct training flights at night, when the sound is clearer because of the open space and low signal interference.

3.Night flight training is carried out in formation, and at this time, the number of fighters is large and the noise generated by the engines is louder.

In short, the roar of planes outside in the middle of the night is likely to be caused by weather factors or flight training, as long as it is not too frequent and continuous, it generally does not affect people's rest and sleep.

Low altitude and high noise for a short time after takeoff. After the plane takes off, it is necessary to leave the site according to certain procedures and routes, and the route will generally be far away from the city and will try to go around.

It should be military aircraft that produce this effect.

Night flight training, general formation flight, fighter jets sometimes hit afterburner, and the noise generated by the engine is very loud.

Whether the plane you see is a passenger or cargo plane or a helicopter.

There is a sound during the day and at night, is it unusually loud at close range? Or is it just a slight high-altitude roar from very high up?!

If it is a passenger plane, it may be due to the seasonality of the recent spring, often the weather is clear and cloudless, and the sight effect is naturally better than in winter, and the visibility.

It's higher. You can always see planes at high altitude.

In fact, it used to be common, but it was not easy to see, and the visibility was low.

If it's a helicopter, or a jet.

Could it be that the local spring needs spring rain in the near future, but there may be a change in the climate, and the local authorities, in order to keep this year's agriculture from being affected, have taken artificial interference to help apply rain, rainfall, and help local crops or plants to bloom or sprout and grow.

Probably, recently a new airport in some province or some city near your Hubei Province has been repaired and is being prepared for use, and recently it is testing each other's flight routes.

Conducting tests or rehearsals for passenger aircraft flights.

Maybe you've been more idle and free lately, and the living environment around you has suddenly become less noisy and you're not so busy lately, so you have the time and mind to notice the difference above the sky.

Maybe it's the plane on the mission, or you add the new route that the sky has recently planned, and now it is commonplace to see planes in the sky, after all, there are too many planes, and there are many planes traveling by plane every day, so there are many planes flying in the sky.

It could be that the state is conducting air exercises. It could be nearby. It is possible that the local ** is collecting the data.

I think it's normal. The sky over our house is day and night, and after a while, a number of planes come over, and the noise is very loud, and we are used to it.

Hello friends, look at the situation you described, don't associate anything with something in this situation.

It is also from Hubei, there are a lot of planes on a recent route from morning to night, there are others before, but the sound is very small and very high and invisible, on this route is flying very low, you can see it very clearly, the sound is very loud.

It's the same on our side, no one can solve my problem, I'm really helping you look forward to it,

I'm here too, it's a little close, and it's loud.

Summary. This sound is usually caused by an airplane flying overhead. Aircraft often produce engine noise and aerodynamic noise, which can be more noticeable when flying at low altitudes or landing and taking off at nearby airports.

This sound is usually caused by an airplane flying overhead. Aircraft often produce engine noise and aerodynamic bucket force noise, especially when flying at low altitude or when the burning finger is landing and taking off near an airport in the attached airspace.

You've done a great job! Can you elaborate on that?

A: This situation may be due to the sound produced by the aircraft flying at low altitudes. The engines and aerodynamics of an aircraft produce a lot of noise.

Airplanes often reduce their flight altitude when taking off, landing, or approaching an airport, which causes the noise to be further amplified. In addition, the airflow and wing vibrations generated by the aircraft during flight can also produce a certain amount of noise. These airplane sounds are more pronounced in cities, which usually have more buildings and hard surfaces that reflect and play loud sounds.

In addition, weather conditions can also affect the propagation of sounds, such as wind direction and humidity. It is important to note that the flight trajectory and operating rules of the aircraft are usually adjusted according to the regulations of the Civil Aviation Authority to minimize noise disturbance to residents and the urban environment. However, due to the impact of flight volumes and urban development, these noises may still be unavoidable.

In order to reduce the impact of aircraft noise on residents, a number of measures have been taken. For example, building soundproof walls near airports, providing aircraft trajectory adjustment, using engine technology with lower noise balances, etc. At the same time, residents can use measures such as soundproofing equipment or closing windows to reduce the noise of aircraft.

In general, the roar of an airplane in the sky is a noise produced by the engines and aerodynamics of the aircraft. This noise is more pronounced in cities, but various measures can be taken to reduce the disturbance to residents.

If you encounter similar behavior, you should report it to the crew in time so that they can deal with it. Crew members are responsible for maintaining flight order and the safety and rights of passengers, and they can take the following measures:

Persuade. The crew may first persuade the occupants to be aware of the impact of their misconduct on other passengers and ask them to cooperate with the crew's instructions.

2.Swap seats. If persuasion fails, the crew may consider finding an alternative seat for the occupant to avoid inconvenience and disruption to other passengers.

3.Negotiate a settlement. If the occupant insists on occupying the seat unreasonably, the cabin crew can consult with him to understand his needs and reasons, and find a solution so that all passengers can be reasonably accommodated.

4.Please instruct the commander of the collapsed base. If the crew is unable to solve the problem, they can consult the ground commander, and the ground commander will make decisions and deal with it.

In short, if you encounter similar problems, you should report them to the crew in time so that they can deal with them, and at the same time avoid disputes and conflicts with seat occupants, so as to protect the safety and rights of yourself and other passengers.

I am located at the junction of Henan, Hubei and Shaanxi provinces, probably from Xi'an Xianyang International Airport.

Or Zhengzhou Xinzheng International Airport is relatively close, or there are multiple routes passing by, you can always hear the roar of planes flying overhead every day, and you can see it with the naked eye when the weather is fine. Over time, I found that I could always hear the roar of the plane during the day, but at night I could only see the plane flashing and flying, but I could not hear the roar. I believe that many people have the same question, so I checked the relevant information to answer it for you.

First, it is well known that there are more flights during the day than at night, and most of the flights at night are concentrated in the first half of the night, and there are basically no flights in the second half of the night (if any, most of them are international flights). There are more flights during the day than at night, so there is a higher chance of hearing a roar during the day.

Second, the Civil Aviation Administration of China.

The flight altitude of a civil aircraft flying at night.

There are clear limitations, and the low air currents at night are unstable and the flight resistance is large, so the flight altitude of the aircraft at night is generally higher than during the day. The plane flies high, that is, at a distance from us, the sound we hear becomes smaller, or cannot be heard.

Third, it is affected by air temperature, humidity, and density. At night, the air temperature is low, the humidity is high, the cold air sinks, the air at high altitude is thin, and the air at low altitude is dense. Whereas, sound attenuates less in air with high temperature and attenuates more in air with low temperature; Attenuation in air with low humidity and large attenuation in air with high humidity; decays less in thin air and more in dense air; So at night, the sound attenuation is greater, and the sound we hear is smaller.

Fourth, it may be that you fell asleep at night and then you couldn't hear.

<> most civil aircraft actually have horns, but its function is completely different from that of car horns, which is not used to warn other aircraft, but is used by the cockpit to remind ground personnel.

That's why I can always hear the roar of airplanes during the day, but not at night. If there is any error, please feel free to correct it.