Aircraft noise at high altitude

Monty Burnz

Hi guys, just a quick question:

Can you hear a plane travelling at high altitude (35,000 feet say) from the ground against normal background noise? I'm assuming that the planes that you can hear (having lived within 10 miles of airports in different locations) are usually much lower down?

Perhaps someone even knows what the decibel level might be at ground level from a plane travelling at that kind of altitude?

Cheers

Blue Punto

I can here them very well at highlevel no problem here in Portlaoise.In the middle of a busy city maybe different though

Infact just as I was typing this I heard AA57 @F/L350 go over the house

cocoshovel

I hear them all the time. I thought this was common knowledge?

Monty Burnz

cocoshovel wrote: »

I hear them all the time. I thought this was common knowledge?

I'm talking about planes at high altitude. I recall seeing planes at high altitude in the distance in a rural setting (particularly on sunny days) and there wasn't a sound to be heard from them. I was hoping that there might be some expert knowledge here on the decibel level that you might expect to hear from such planes.

highlydebased

Monty Burnz wrote: »

I'm talking about planes at high altitude. I recall seeing planes at high altitude in the distance in a rural setting (particularly on sunny days) and there wasn't a sound to be heard from them. I was hoping that there might be some expert knowledge here on the decibel level that you might expect to hear from such planes.

Depends on the wind/weather conditions generally

iPlop

highlydebased wrote: »

Depends on the wind/weather conditions generally

There was a luftansa 744 flying over my house a few weeks back @37,000ft and I could hear it quite loudly.Then the other day the same thing but silence.I can usually hear them if it's quite calm, but if it's windy, forget it.

bkehoe

Out the country here in Co Wexford there's no problem hearing high altitude aircraft. Sometimes in the calm of night they can be very loud.

The sonic boom from Concorde used to be quite audible at times too (so much so that birds would fly from the trees) even though it was only going supersonic many tens of miles out to sea.

el tel

When I was a kid you could always hear the milk plane fly over :P

280special

Didnt realise it before i found those online tracking sites but what i often thought , on those cloudy days, was a locally bound a/c was actually something heading across at 35K !

But having said that they do appear to be louder than before even on the brighter days.

cocoshovel

Yeah, even at high altitude. As a kid I grew up in Waterford city so planes were always flying up at like 30k feet over head and you would hear them. Of course the sound would be a bit behind the location of the plane because it takes a while for it to travel down to ground level. Now I live in Kilkenny and the flight path goes directly over my house from USA to London so I hear them even more.

I suppose if you didn't live in an area with regular high altitude fights above you, you wouldn't know really.

owenc

Yes of course you can don't be silly. I live in an area were most of the flights are transatlantic flights.. in a normal day i'd say about 40 transatlantic flights fly over my house so they are quite frequent, if its quiet you can definitely hear them (you can even hear them over cars) but if its stormy you can only hear them slightly. Its funny aswell because when the flights are out over the atlantic ocean if i have binoculars i can still see them! (like 50 miles out too) :eek: They have to be high though like 35000ft.

amen

Its funny aswell because when the flights are out over the atlantic ocean if i have binoculars i can still see them! (like 50 miles out too) They have to be high though like 35000ft.

basic trigonometry. nothing funny about it.

owenc

amen wrote: »

basic trigonometry. nothing funny about it.

I was just stating that it was interesting no need to be smart.:rolleyes:

amen

sorry couldn't resist.

280special

amen wrote: »

sorry couldn't resist.

Yes of course you can don't be silly.

owenc

amen wrote: »

sorry couldn't resist.

Really well that's good for me now I will know who to ignore.