Skip to main content

Questions tagged [noise]

Questions related to aviation sound noise or regulations thereof.

Filter by
Sorted by
Tagged with
70 votes
4 answers
76k views

Why does the Boeing 787 engine nacelle exhaust have such an unusual shape?

Why does the Boeing 787 nacelle have this unique shape at the exhaust: I haven't seen it on any other airplanes, does it serve an aerodynamic purpose or help engine efficiency or is it just to look ...
Lnafziger's user avatar
  • 59k
15 votes
3 answers
3k views

Do nacelles around aircraft engines help in reducing the engine sound?

I know that the nacelles around the aircraft engines are actually a housing and are generally lightweight and have may components like inlet cowl, fan cowl, etc., but do they help in reducing the ...
NitinG's user avatar
  • 6,889
20 votes
2 answers
3k views

How do turbofan nacelle lengths compare?

For example, compare the JT9D and the PW4000 below (both from Pratt & Whitney, both on a 747): (Left, Right) The PW4000 has a longer forward nacelle, and a covered exhaust cone. On the inside—...
user avatar
21 votes
5 answers
50k views

What causes descending aircraft to make a noise like a giant blown bottle?

I've lived for years about eight miles NW of Boston's Logan Airport. Although I can't say we get a lot of aircraft noise, once in a while, due to winds or air traffic, there will be a long line of ...
Daniel Griscom's user avatar
5 votes
3 answers
7k views

Why do most A320s make that distinct scream on takeoff?

I've noticed that the engines on the A320 make a very a distinct sound on takeoff. Is there something about the CFM-56 series that causes this? This noise can be heard in this video.
Madhav Sudarshan's user avatar
55 votes
4 answers
30k views

Can I stop crop dusters repeatedly flying over my home?

I have a crop-duster spraying the fields around me often. He flies over my house no matter what field he is spraying every few minutes. I think he uses my house as a pivot point. The old pilot rarely ...
denise lynn's user avatar
38 votes
1 answer
11k views

Why was there a rattling noise coming from the left engine of A319?

I recently flew on an Airbus A319. When boarding the aircraft from the front entrance we passed in front of the left engine. The fan blades were spinning and there was a rattling noise (like when a ...
Fabrizio Mazzoni's user avatar
11 votes
5 answers
4k views

Is landing without engine power routinely feasible?

Considering that airplanes are very noisy, could one routinely land them with the engines turned off, gliding onto the runway? Could the engines be started fast enough for an emergency situation?
yippy_yay's user avatar
  • 7,375
12 votes
1 answer
9k views

What is the buzzing noise generated by the engines in this 777 takeoff video?

I've flown a few times in my life, both in economy and executive class. Every time I fly in executive, during takeoff, there is a different noise from the engines. In economy class (behind the engines)...
Délisson Junio's user avatar
23 votes
2 answers
6k views

Why aren't modern helicopters quieter?

Living closer to a Sikorsky factory, I can attest that modern civilian (and military) helicopters are quite noisy. In any case, they are considerably louder than light aircraft, turboprops, and even ...
RoboKaren's user avatar
  • 8,071
22 votes
2 answers
29k views

Do helicopter rotor tips regularly go supersonic?

In my question about helicopter noise, I made the assumption that one reason they are so darn noisy is that the main rotor tips go faster than the speed of sound. @FreeMan questioned whether that was ...
RoboKaren's user avatar
  • 8,071
15 votes
3 answers
7k views

Why does a jet engine acquire a metallic whine when in full power? [duplicate]

I had a flight yesterday on an AA Embraer ERJ-190. As the plane idled at the end of the runway there was the familiar high-pitched jet whistle, which increased in pitch as the engine started spinning ...
Daniel Griscom's user avatar
13 votes
2 answers
7k views

Can pilots hear their passengers clapping on touchdown?

Something that just popped into my head: I've been on a few easyJet and Ryanair flights where a lot of passengers clap and cheer on touchdown. Would the pilots be able to hear this? Here's an example ...
Danny Beckett's user avatar
6 votes
2 answers
3k views

What causes the "growl" of some large turbofans at takeoff thrust?

There are some (all?) large turbofans which emit a distinct "growl" (some people call it a "buzzsaw" sound) at takeoff thrust. What causes it? I've seen it explained (as in this question) as the fan ...
Anthony X's user avatar
  • 3,400
5 votes
2 answers
1k views

What noise reduction measures were taken in the time between hush kits and chevrons?

In older jets such as 727 hush kits are used in the engines to reduce noise. In very modern jets such as 787 or 747-8F, chevrons are used for the same purpose. What happened in between? The switch to ...
Moobie's user avatar
  • 173
20 votes
4 answers
8k views

Are seaplanes allowed to taxi in residential areas?

There's a small pond/lake behind my house. A sea plane was just going around it. It was very loud and got like 10 feet from the shore. It's just going in circles and won't take off and leave. This is ...
Kelly 's user avatar
  • 227
13 votes
6 answers
3k views

Can an experienced airplane spotter identify planes only by sound?

I come from a background in railroad watching, and often times one can identify the maker of a railroad locomotive purely by sound. Maybe not the exact model of locomotive, but at least what type of ...
Milwrdfan's user avatar
  • 1,789
13 votes
1 answer
6k views

What causes the distinct sounds of a jet engine?

I live a few miles from a major airport (BOS), under the path that a lot of airplanes use to depart. The planes are somewhat low over my house -- high enough that it's not deafening, but low enough ...
yshavit's user avatar
  • 1,163
12 votes
1 answer
2k views

What causes the sudden spool-up sound from an F-16 when enabling afterburner?

What causes the sudden spool-up sound from an F-16 when enabling afterburner? I've included a video to make it clear what sound I'm referring to: at 1:16, I assume ...
AlphaCentauri's user avatar
11 votes
1 answer
6k views

Will you be able to hear a supersonic aircraft flying away from you?

I'm wondering if you could be able to hear the sound emitted by an aircraft say traveling at Mach 2 away from you. I wondered if it might shift the emitted frequencies beyond the audible range. Would ...
monkey's user avatar
  • 111
11 votes
2 answers
3k views

Why is a Lockheed MC-130J Commando II creating such a loud droning sound?

Today I heard a loud droning sound which is really unusual in the area of west London I live in; so I went on ADS-B exchange and it showed a USAF Lockheed MC-130J Commando II flying literally right ...
Daniel K's user avatar
  • 331
10 votes
3 answers
11k views

Why are light aircraft engines so noisy?

I live near an airport where students spend a lot of time flying circuits. During the base leg, pilots can be heard reducing engine revs prior to the final left/right turn to line up with the runway. ...
IanT8's user avatar
  • 326
9 votes
1 answer
1k views

Why does the chevron-shaped engine suffer losses in thrust performance?

From here I found out a lot about chevrons on the Boeing 787, but not enough to satisfy why it results in performance loss. My thinking was originally, if they are "cutting triangular holes" in the "...
DrZ214's user avatar
  • 17.8k
8 votes
1 answer
1k views

What does aerodynamic noise of an airliner sound like in landing configuration?

I want to know what aerodynamic noise an airliner makes when flying with both engines shut down. Specifically, it is the sound made by air passing a plane which is in landing configuration, with gear ...
wael rokbani's user avatar
8 votes
1 answer
1k views

What is the major source of engine noise for non-propeller aircraft?

Sparked by this question: Take any non-propeller powered aircraft, when idle, the sound produced by the engines are fairly low pitched, and as the engine spins up, increasing in pitch before becoming ...
JamesENL's user avatar
  • 437
7 votes
3 answers
12k views

Which light aircraft are known to have a quiet cockpit?

Are some light aircraft known as being significantly quieter in the cockpit than others ? How quiet might the quietest light aircraft be from the inside ? At least ten years ago I was reading an ...
glaucon's user avatar
  • 1,655
5 votes
1 answer
1k views

What are the relative internal noise levels in various aircraft?

What are the relative noise levels in various aviation scenarios for observers seated inside an aircraft? I'm sure the specifics depend on model but I'm curious if any general trends can be drawn that ...
curious_cat's user avatar
  • 8,456
3 votes
0 answers
235 views

F-16: MAIN PWR ticking sound, what is it?

What is that sound that starts when MAIN PWR switch is turned on in the F-16? Its sorta like a fast ticking sound. Why is it there, what makes it, when does it stop? And is it also there when only ...
Invariant's user avatar
  • 1,731
3 votes
1 answer
2k views

What do we hear, on the ground, from a helicopter in flight?

Last week I heard a helicopter approaching from a distance. The sound it made was a very distinct and deep wop wop wop at a remarkably slow two beats per second, more or less. As it came closer, the ...
Daniele Procida's user avatar
2 votes
2 answers
626 views

Are aircraft sounds publicly available in a repository?

Referring to the automated callouts and sounds made by the fwc, tcas, gpws, pws, etc. — are these available to download in one repository at all? For any aircraft, Airbus or Boeing. ...
Danny Beckett's user avatar
1 vote
1 answer
2k views

How does altitude affect sound? [closed]

So I know that altitude affects the speed of sound because of temperature differentials in the atmosphere, but I am curious what else affects how we hear planes overhead? When a plane flies overhead, ...
cosmikwolf's user avatar