Streaking noise?

[Mungous]

I'm fairly sure this would have something to do with passing aircraft, but just wanted to confirm it or see if anyone else has experienced it and/or can explain why it happens.

Sometimes when I'm out shooting approach, theres often this 'streaking' noise after an aircraft has flown over, usually happens 20-30 seconds after the plane has passed. (it's happened with jets and props). It seems like there's lightning ripping across the sky right above your head. Its only happened on cloudy days so far. Can anyone explain why it occurs? :-)

[Myriad]

Its the wing tip vortices...

http://www.centennialofflight.gov/essay/Theories_of_Flight/Vortex/TH15G1.jpg

[photoid=5623246]

If you look in that photo, from the winglets, those white lines... the theory behind them can be found here (http://www.centennialofflight.gov/essay/Theories_of_Flight/Vortex/TH15.htm)

You might hear it more on cloudy days due to the moisture in the air, however you will hear them all the time if in the right spot and listen carefully enough

[Colin Parker]

It is amazing what you can hear from different aircraft types as well. 757s and DC10s/MD11s always seem to leave a lot of noise.

Something which is also interesting to watch is when an aircraft approaches over the sea, like in Hong Kong. Often you can see streaks in the water where the vortices are blowing the surface of the sea, and sometimes you can even get small water spouts which can linger for up to a minute. It is amazing when you can visualise the disruption to the air which is normally invisible to us.

[screaming_emu]

Originally I was looking for a video (though it may have been an animated GIF of a 747 flying over some smoke stacks going into Kai Tak, but here's what wake turbulence looks like for a dirty (flaps down, gear down, has nothing to do with how shiney the plane is), slow flying, 747 looks like if you add a little smoke to the mix. If I can find the video I'm looking for I'll come back and post it.

http://www.carneyaviation.com/gallery/images/smoke2.jpg

[Irfan]

Image above looks almost like a hurricane!

[Mungous]

Originally I was looking for a video (though it may have been an animated GIF of a 747 flying over some smoke stacks going into Kai Tak, but here's what wake turbulence looks like for a dirty (flaps down, gear down, has nothing to do with how shiney the plane is), slow flying, 747 looks like if you add a little smoke to the mix. If I can find the video I'm looking for I'll come back and post it.

http://www.carneyaviation.com/gallery/images/smoke2.jpg
Is that for real? That 'one big swirl' doesn't seem to happen with fog or low clouds. :skeptic:

[screaming_emu]

sure it does

http://www.carneyaviation.com/gallery/images/c500turb.jpg

[Mungous]

sure it does

http://www.carneyaviation.com/gallery/images/c500turb.jpg
:shock: Ok, I beleive you now ;-)

[ASpilot2be]

I have a friend in Juneau whos house is a couple hundred feet below the glide slope. When those wing tip vortices hit the trees they make an insane snapping and cracking. Even seen a crow get flipped upside down:). I want to hear a 757s wing tip vortices in the trees:).

[screaming_emu]

Yo Alec, when you were flying last summer (I think that's when it was) did you get to doing any steep turns? If you do them just right, you can actually hit your own wake turbulence. Its nothin too bad, just a nice little bump on the plane that lets you know you did it right. That still shows that even in a light aircraft such as a cessna or a piper how strong the turbulence can be if it sticks around long enough for you to do a 360 and then hit it again.

[ASpilot2be]

Yo Alec, when you were flying last summer (I think that's when it was) did you get to doing any steep turns? If you do them just right, you can actually hit your own wake turbulence. Its nothin too bad, just a nice little bump on the plane that lets you know you did it right. That still shows that even in a light aircraft such as a cessna or a piper how strong the turbulence can be if it sticks around long enough for you to do a 360 and then hit it again.
Yeah, that was last summer. We did do steep turns, but I dont remember hitting my wake turbulence. I remember lots of thermals on the return trip after practicing over the water.

[wannabepilot777]

I frequently run in a park under the northbound approach to SEA and I have always loved that sound. To me, it sounds almost like tin foil being crinkled and ripped at the same time.


edit: MY 700th POST! I RULE.....well, nobody else was going to say it!

[MaxPower]

Unforgetable sound. I have it recorded on my phone. Will download it soon !

[andrew_c]

Yesterday we were getting them from all sorts of aircraft... but mainly the 757s and the CRJ200s. I found the CRJs made the loudest and longest lasting ones out of them all... Pretty cool and it scares the kids :twisted:

[MaxPower]

Yesterday we were getting them from all sorts of aircraft... but mainly the 757s and the CRJ200s. I found the CRJs made the loudest and longest lasting ones out of them all... Pretty cool and it scares the kids :twisted: I think the 737's make the loudest noise. but yeah, the CRJ's is in that league too !

[ACman]

edit: MY 700th POST! I RULE.....well, nobody else was going to say it!

w0oT! My 2,358 Post. Excellent, lets all have a party.

The sound of the engines are also a contributing factor to the streaking sound.

[MaxPower]

The sound of the engines are also a contributing factor to the streaking sound. Hmm Excatly how is it contributing to the noise again .. ???

[ACman]

Hmm Excatly how is it contributing to the noise again .. ???

Engines make noise John.

http://flightlevel350.com/video_streaming.php?id=4488 A320 with IAE's
http://flightlevel350.com/video_streaming.php?id=4490 A320 with CFM's

http://flightlevel350.com/video_streaming.php?id=1974 767 with PW's
http://flightlevel350.com/video_streaming.php?id=2641 767 with GE's

[MaxPower]

Engines make noise John.

http://flightlevel350.com/video_streaming.php?id=4488 A320 with IAE's
http://flightlevel350.com/video_streaming.php?id=4490 A320 with CFM's

http://flightlevel350.com/video_streaming.php?id=1974 767 with PW's
http://flightlevel350.com/video_streaming.php?id=2641 767 with GE's

Well, That was actually not what I was hoping to hear.

More like the roar of the engines cant be a direct contributor to the squeky/streaking sound during the pass-over. Well just a little bit, I guess !

[ACman]

Well, That was actually not what I was hoping to hear.

More like the roar of the engines cant be a direct contributor to the squeky/streaking sound during the pass-over. Well just a little bit, I guess !

Yeah, well its more so on the older screamers like the Russin gigs or the older ones with the PW JT8D's or JT3D's. Or even RR Conways.