Super loud noise, was it a jet?

[Domzh]

Today at 14:13 local time in the area of 8180 Bülach, Switzerland I heard a massive noise that I have never heard before. My wife recorded the noise by sheer accident. All windows were closed, we live in a rather high end apartment with good isolation so maybe this altered / filtered the distinct rumbling from a passing jet. I only ever heard jets when i was hiking somewhere, so i could very much lack a reference for how it sounds from the inside.

Also we usually never have military jet training at our location, or at least i never realized it.

It sounded like a super loud EV, like the sound an electric drive makes, just way way louder. Where we live is usually no military air traffic, and it lacked the usual rumble i personally connect with military jets. There is a street appx 500m away but its mostly used by cyclists.

Do you guys have any idea what this could have been? Does this sound like a jet to you?

The swiss airforce mentions low altitude flight trainings starting today but taking place in the UK (German, Link to the official Swiss Airforce Website)

Maybe they were flying to the UK and just had fun doing a low passing by for preparation even though this is usually not a training area?

 

[Jack Mallory]

It sounds to me like the de-acceleration of a low-flying military jet (or a very low-flying commercial jet), but if that were a one-off occurrence in your area, it would be strange. It does sound similar to what one might typically hear around a military airfield.

 

[jplaza]

It sounds to me like the de-acceleration of a low-flying military jet (or a very low-flying commercial jet), but if that were a one-off occurrence in your area, it would be strange. It does sound similar to what one might typically hear around a military airfield.

The "de-acceleration" sound is only the Doppler effect of the moving object. The sound goes from high pitch (it is approaching) to a lower pitch (when it goes away).

Anyway, it doesn't sound like a military plane to me, at least not a fighter jet. I live in a place where planes fly rather low and not too fast, as they start approaching for landing to the airport. To me it sounds like that: a low altitude / low speed plane.

 

[jarlrmai]

At that time there was a private jet (NJE337B) and a A320 (SWR817) over Bulach on descent into Zurich Airport which is only a few ks south of Bulach.

https://www.planespotters.net/photo/1548168/cs-ltp-netjets-europe-cessna-680a-citation-latitude

 

[Duke]

The "de-acceleration" sound is only the Doppler effect of the moving object. The sound goes from high pitch (it is approaching) to a lower pitch (when it goes away).
Anyway, it doesn't sound like a military plane to me, at least not a fighter jet. I live in a place where planes fly rather low and not too fast, as they start approaching for landing to the airport. To me it sounds like that: a low altitude / low speed plane.

And it appears (see map) the OP lives less than 10 km from Zurich (International) Airport, so a low & slow aircraft being in his immediate vicinity would not be a surprise.

For what it's worth, the first aircraft that popped into my mind when I saw/heard the video was the Airbus A400M, called "Atlas" in RAF service. They have a very distinctive sound. I'm pretty sure the Swiss do not operate this aircraft, but several European nations do.

If it was an Atlas, maybe the RAF sent it to Switzerland to airlift Swiss support/maintenance personnel, support equipment, spares, etc., to the site of their low level training in the UK. I don't think the Swiss operate any transport aircraft of any size, so they would have had to rely on someone else to provide the airlift capability they lack.

 

[john.phil]

A400M fly-by for comparison - Mach Loop (00:18 - 00:25)


Source: https://www.youtube.com/watch?v=URSit14R9OE&t=19s

 

[John J.]

The A400M in the video posted by @john.phil does sound very similar to the noise recorded by @Domzh to my untutored ear,
and @Duke's mention of the A400M before john.phil posted his clip adds credence to that theory.

I won't pretend to be able to tell aircraft types by their sound, so I can't rule out @jarlrmai's identified aircraft as possible contenders.

But to me, what @Domzh recorded sounds very much like an aeroplane of some sort.
(Incidentally, D., why the numbered bags on the walls? What quirk of continental life am I missing out on? )

 

[jarlrmai]

I made a mistake at 13:13 UTC was 14:13 Zurich time.

AUA569 an A321 was landing at 13:13 UTC

 

[Trailspotter]

I think this military trainer (PC21 A-108) is a possible culprit.

This video is a good example of how it sounds outside. From my personal experience, from the inside different passing aircraft sound alike and are heard the best when they fly right over the house. A small plane or helicopter can sound much louder than a biz jet taking off in our local airport just a mile away. @Domzh , could you please check how close was the PC21 track to your place.

 

[jarlrmai]

Yeah I saw that one as well, I think if we had a more exact timestamp (from the video metadata) and location we'd be able to say which plane it was.

 

[Trailspotter]

Yeah I saw that one as well, I think if we had a more exact timestamp (from the video metadata) and location we'd be able to say which plane it was.

A plane on the approach to ZRH would be a regular occurrence, whereas the military trainer flight could be a one-off.

 

[john.phil]

I think this military trainer (PC21 A-108) is a possible culprit.

Sound of the trainer during multiple passes (00:43 - 00:46):

Source: https://www.youtube.com/watch?v=tQAaRpGTSL8&t=43s


PC21 trainer sound (muffled):

Audio from OP (boosted):

 

[flarkey]

I think this military trainer (PC21 A-108) is a possible culprit.
View attachment 73000
This video is a good example of how it sounds outside. From my personal experience, from the inside different passing aircraft sound alike and are heard the best when they fly right over the house. A small plane or helicopter can sound much louder than a biz jet taking off in our local airport just a mile away. @Domzh , could you please check how close was the PC21 track to your place.

This looks 100% like it to me.

 

[Ridcully]

It sounded like a super loud EV, like the sound an electric drive makes, just way way louder. Where we live is usually no military air traffic, and it lacked the usual rumble i personally connect with military jets. There is a street appx 500m away but its mostly used by cyclists.

Do you guys have any idea what this could have been? Does this sound like a jet to you?

Yes this sounds familiar.

I live around 20km from a small airport and above our village all planes coming from the east turn and enter the landing approach. Normally you barely notice them even when they are flying relatively low. But under certain conditions, once every few month or so, a jet makes such a noise. A very low-frequency hum that is partly already in the infrasound range.

Due to the rare occurrence I am suspecting it has something to do with the weather conditions, maybe an inversion.

Article:

When an inversion layer is present, if a sound or explosion occurs at ground level, the sound wave is refracted by the temperature gradient (which affects sound speed) and returns to the ground. The sound, therefore, travels much better than normal. This is noticeable in areas around airports, where the sound of aircraft taking off and landing often can be heard at greater distances around dawn than at other times of day, and inversion thunder which is significantly louder and travels further than when it is produced by lightning strikes under normal conditions.

Source: https://en.wikipedia.org/wiki/Inversion_(meteorology)

However I never verified that assumption until now.

 

[Domzh]

I think this military trainer (PC21 A-108) is a possible culprit.
View attachment 73000
This video is a good example of how it sounds outside. From my personal experience, from the inside different passing aircraft sound alike and are heard the best when they fly right over the house. A small plane or helicopter can sound much louder than a biz jet taking off in our local airport just a mile away. @Domzh , could you please check how close was the PC21 track to your place.

i live slightly off (east side) to buelach, and the track goes directly over my location. does the time match?

 

[Domzh]

Yeah I saw that one as well, I think if we had a more exact timestamp (from the video metadata) and location we'd be able to say which plane it was.

its 14:13 local time (gmt +1 / utc +1 / CET) as mentioned in the initial post

 

[jarlrmai]

Planes can travel a fair bit in a minute, ideally the second when the noise occurs and a region of the city would help narrow it down.

 

[Domzh]

you guys rock! the sound comparison and flight track are spot on.

this thing sounds insane

thanks everyone!

 

[captancourgette]

I hear a very similar sound quite often always when landing never take off (barcelona in flightpath) just from a normal passenger jets i.e. non military.
Yes they're flying low but the thing is 5 minutes later you can have another plane pretty much flying the same path/height but those will sound like the normal jet noise. I've been curious about this for a while some sound so different.
Next few times I'll check https://radar.planespotters.net/ to see what make of plane it was to satisfy my curiousity

 

[Alexandria Nick]

I've lived almost my whole life within a few miles of an airport of one kind or another. As soon as I watched that video, I thought "single engine turboprop." They have a really unique sound. You can tell a turboprop from another prop driven aircraft because it doesn't have the same kind of chattering sounds. Almost sounds more like an F1 car or something. Single engine ones seem to have a bit of a buzz-y sound to them that twin engine ones lack.

Fortunately, there aren't a lot of single engine turboprops in the area to choose from, so that really narrows it down.

 

[Trailspotter]

i live slightly off (east side) to buelach, and the track goes directly over my location. does the time match?

It does (to a minute).

 

[Duke]

I think this military trainer (PC21 A-108) is a possible culprit.
View attachment 73000
This video is a good example of how it sounds outside. From my personal experience, from the inside different passing aircraft sound alike and are heard the best when they fly right over the house. A small plane or helicopter can sound much louder than a biz jet taking off in our local airport just a mile away. @Domzh , could you please check how close was the PC21 track to your place.

319 kts @ 1775 feet is hauling ass, especially near a major airport. If I remember correctly, the FARs restrict aircraft in the US from flying faster than 200 kts below 2500 ft near bigger airports. I don't recall specifics any more, and yes there are exceptions. There are probably similar restrictions through ICAO, EASA, and Swiss regulations.

Looks like he flew a direct approach, maybe he needed to be on the ground in a hurry. Is there anyway on AB Exchange to determine if the pilot(s) of the Pilatus declared an IFE?

 

[Trailspotter]

Looks like he flew a direct approach, maybe he needed to be on the ground in a hurry. Is there anyway on AB Exchange to determine if the pilot(s) of the Pilatus declared an IFE?

No, the Pilatus did not land at ZRH, but eventually returned to its origin, Emmen Military Air Base (EML).

 

[Duke]

No, the Pilatus did not land at ZRH, but eventually returned to its origin, Emmen Military Air Base (EML).
View attachment 73015

Ok, I thought your initial graphic (post #9 above) showed the a/c landing at ZRH, but you were just showing how close it came to @Domzh, and therefore ZRH. Still have a relatively high speed/low level pass near a major airport.

 

[john.phil]

319 kts @ 1775 feet is hauling ass, especially near a major airport. If I remember correctly, the FARs restrict aircraft in the US from flying faster than 200 kts below 2500 ft near bigger airports. I don't recall specifics any more, and yes there are exceptions. There are probably similar restrictions through ICAO, EASA, and Swiss regulations.

In Switzerland and Europe in general (EASA), the speed limit below 10,000ft (FL100) is 250kts indicated airspeed (KIAS). The map in post #9 is displaying ground speed (GS), not KIAS; thus, the aircraft was doing 319kts GS. So, for the pilot to be respecting the 250KIAS limit, which corresponds to approximately 256kts true airspeed (KTAS) for 1775ft altitude, there should have been a tail wind component of at least 63kts (319kts GS - 256KTAS).

Skyguide is the company that provides air traffic control in Switzerland and neighbouring airspaces -> https://www.skyguide.ch/

Skyguide VFR manual:
https://www.skybriefing.com/evfr-manual-gen
https://skybriefing.com/documents/10156/645440/eVFR_eGEN_en_10_2024.pdf

From the VFR manual, pages 147, 148 and 150 read:

 

[captancourgette]

I hear a very similar sound quite often always when landing never take off (barcelona in flightpath) just from a normal passenger jets i.e. non military.
Yes they're flying low but the thing is 5 minutes later you can have another plane pretty much flying the same path/height but those will sound like the normal jet noise. I've been curious about this for a while some sound so different.
Next few times I'll check https://radar.planespotters.net/ to see what make of plane it was to satisfy my curiousity

I can't seem to edit my previous post
OK this plane just made the same noise
https://radar.planespotters.net/?icao=3444ca

 

[Mendel]

I can't seem to edit my previous post
OK this plane just made the same noise
https://radar.planespotters.net/?icao=3444ca

EC-MAI Vueling Airbus A320-214(WL)

Not a single engine turboprop by any means.