TimePilot
Topic Author
Posts: 290
Joined: Sat Sep 03, 2005 10:40 pm

Sound Of Wind After Landing?

Tue Mar 17, 2009 1:23 am

Hello,

I went to the old Nagoya airport yesterday and hung around the park at the end of the runway. It was good timing because a C-130 of the Self-Defense Force was doing repeated touch-and-goes. I took this video of it flying overhead:

http://www.youtube.com/watch?v=poq3zOsmUcs&feature=channel_page

About 1 minute after I took this video, there was the sound of wind all around. It sounded like when you drive really fast and open the car window up a little bit. It lasted for about 10 seconds then stopped. I've also noticed the sounds after JAir CRJs come in, too.

What is that noise? Vortex winds?

Thanks in advance.
 
vikkyvik
Posts: 11857
Joined: Thu Jul 31, 2003 1:58 pm

RE: Sound Of Wind After Landing?

Tue Mar 17, 2009 2:30 am



Quoting TimePilot (Thread starter):
What is that noise? Vortex winds?

Probably.

Wingtip vortices (and flap tip vortices, really anywhere that there are symmetrical vortices on either side of the airplane) sink slowly aft of an aircraft, as each vortex pushes down on the other.

As the vortices near the ground, they start spreading out from each other as well.

I've never heard/felt vortices after an airplane has passed, but I'd imagine that's what it was, if there wasn't much wind or other possible sources of moving air. From the video, looks like you'd be in pretty good position to get the tip vortices from the left wing.
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".
 
Fly2HMO
Posts: 7207
Joined: Sat Jan 24, 2004 12:14 pm

RE: Sound Of Wind After Landing?

Tue Mar 17, 2009 2:46 am



Quoting TimePilot (Thread starter):
What is that noise? Vortex winds?

Definitely. If you're close enough to the approach end of the runway you can definitely feel, and hear them.

A few nights ago I was taking night pictures at my local airport. The wind was dead calm. Then a a Horizon Q400 came in and just about 30 seconds later I heard the vortices and then about a minute later I felt the breeze, then everything went quiet again. I've found that bigger non-wingleted planes, and large prop-planes, tend to make interesting noises, sometimes you'll here clapping or whooshing sounds.

Quoting Vikkyvik (Reply 1):
I've never heard/felt vortices after an airplane has passed,

Really? And you call yourself an aviation enthusiast?  Yeah sure  Wink
 
vikkyvik
Posts: 11857
Joined: Thu Jul 31, 2003 1:58 pm

RE: Sound Of Wind After Landing?

Tue Mar 17, 2009 2:55 am



Quoting FLY2HMO (Reply 2):

Really? And you call yourself an aviation enthusiast?

 grumpy 

I call myself an aerospace engineer. I sit in a cube in a dull room with flourescent lights and stare at my computer with my horn-rimmed glasses and pocket protector. The sun scares me.

 Wink
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".
 
Fly2HMO
Posts: 7207
Joined: Sat Jan 24, 2004 12:14 pm

RE: Sound Of Wind After Landing?

Tue Mar 17, 2009 3:08 am



Quoting Vikkyvik (Reply 3):
I call myself an aerospace engineer.

Ooohh well that explains a lot Big grin  duck   Wink
 
ANITIX87
Posts: 2958
Joined: Mon Mar 07, 2005 4:52 am

RE: Sound Of Wind After Landing?

Tue Mar 17, 2009 3:20 am

When I went to Billy Joel's concert at Shea Stadium last summer there was NO wind that night, and they were using runway 31, with the expressway visual at LGA. The planes were flying above the stadium before beginning their turn, and about two minutes later, an enormous breeze would sweep through the stadium. You could almost hear 50,000 people sigh in unison because it was so hot and muggy that evening.

TIS
www.stellaryear.com: Canon EOS 50D, Canon EOS 5DMkII, Sigma 50mm 1.4, Canon 24-70 2.8L II, Canon 100mm 2.8L, Canon 100-4
 
TimePilot
Topic Author
Posts: 290
Joined: Sat Sep 03, 2005 10:40 pm

RE: Sound Of Wind After Landing?

Tue Mar 17, 2009 11:09 pm

Thanks for the replies!  Smile
 
GST
Posts: 808
Joined: Wed Jun 11, 2008 10:27 am

RE: Sound Of Wind After Landing?

Wed Mar 18, 2009 1:26 am

Just to chuck another possibility in the pot, a thermal could have gone through. You can get quite strong breezes inside a thermal, and often if they are narrow ones they may get strong enough to get quite loud, not to mention pass over about as fast as you said on many days.

Just putting it out there, but i would agree the most likely answer is still trailing vortecies.
 
2H4
Posts: 7960
Joined: Tue Oct 19, 2004 11:11 pm

RE: Sound Of Wind After Landing?

Wed Mar 18, 2009 4:36 am

Sounds like this is what happened, albeit on a smaller scale:

http://i41.tinypic.com/5lp2jr.jpg


I've heard the vorticies from an Avro RJ once. The jet passed overhead on short final, and about 15-30 seconds later, I could hear them. It almost sounded like two large lengths of wire being pulled taut against each other along the approach path. It was an echoing/tearing sound that seemed to travel very quickly back and forth along the approach path

2H4
Intentionally Left Blank
 
OldAeroGuy
Posts: 3208
Joined: Sun Dec 05, 2004 6:50 am

RE: Sound Of Wind After Landing?

Wed Mar 18, 2009 10:56 pm



Quoting Vikkyvik (Reply 1):
I've never heard/felt vortices after an airplane has passed, but I'd imagine that's what it was,

If you play golf, play a round on a course near the end of a runway at a large airplane airport. There's one at the south end of SeaTac.

You'll hear and feel a lot of vortices.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
soon7x7
Posts: 2267
Joined: Thu May 04, 2006 10:51 am

RE: Sound Of Wind After Landing?

Wed Mar 18, 2009 11:22 pm

If you can get to JFK 13 left....they come right over...the plane will already be on the ground yet the air above you is tearing with nasty sounds...Always gives me visions of some poor sucker in a J-3 getting ripped apart by one of these...  spin 
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: Sound Of Wind After Landing?

Thu Mar 19, 2009 12:18 am



Quoting 2H4 (Reply 8):
It almost sounded like two large lengths of wire being pulled taut against each other along the approach path. It was an echoing/tearing sound that seemed to travel very quickly back and forth along the approach path

Great description! That's exactly what they sound like.

Quoting OldAeroGuy (Reply 9):

If you play golf, play a round on a course near the end of a runway at a large airplane airport. There's one at the south end of SeaTac.

There's also a park at the north end of Boeing field that's fantastic for this (if they're on 13R)...the park is only a few hundred yards from the threshold.

Tom.
 
ba97
Posts: 348
Joined: Sat Apr 10, 2004 9:42 am

RE: Sound Of Wind After Landing?

Thu Mar 19, 2009 12:40 am

Woodbine golf course in Toronto is a great place to have fun hearing them when planes are landing to the west on the south runway-although you do cause a delay in play because it is too much fun hearing them. The description of a wire being pulled/whipped is exactly the sound you hear. You sometimes hear a crack. You can hang out on the street next to the course and hear them but there is something about being on a golf course with the trees walking and hearing them in the silence of the course that makes them better.
there is economy class, business class, first class...then Concorde..pure class
 
vikkyvik
Posts: 11857
Joined: Thu Jul 31, 2003 1:58 pm

RE: Sound Of Wind After Landing?

Thu Mar 19, 2009 4:07 am



Quoting OldAeroGuy (Reply 9):

If you play golf, play a round on a course near the end of a runway at a large airplane airport. There's one at the south end of SeaTac.

Ugh, trust me, I would love to! I do play golf, but sadly I don't know of any golf courses in the LA area that are near runway ends.

I have been to the In'n'Out by the 24R threshold plenty of times, but it might be a bit too far offset from the flight path to feel them. Plus it's pretty noisy over there.
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".
 
buckfifty
Posts: 1278
Joined: Tue Oct 16, 2001 4:05 pm

RE: Sound Of Wind After Landing?

Thu Mar 19, 2009 10:31 am



Quoting Ba97 (Reply 12):
Woodbine golf course in Toronto is a great place to have fun hearing them when planes are landing to the west on the south runway-although you do cause a delay in play because it is too much fun hearing them. The description of a wire being pulled/whipped is exactly the sound you hear. You sometimes hear a crack. You can hang out on the street next to the course and hear them but there is something about being on a golf course with the trees walking and hearing them in the silence of the course that makes them better.

If you're in the Wendy's parking lot while 23 is in use, you will definitely hear the shearing effects caused by the vorticies. In fact, if you look at the trees in the said parking lot, you will see that they grow a certain way...
 
ba97
Posts: 348
Joined: Sat Apr 10, 2004 9:42 am

RE: Sound Of Wind After Landing?

Fri Mar 20, 2009 12:09 am

I will have to look at those trees at Wendys, never occurred to me- thanks. You get a multi set of thrills there in the afternoon with the Europe flights coming in and you see them approach over the light stands slowly growing in size, the low pass over, then the vortice sounds.
there is economy class, business class, first class...then Concorde..pure class
 
wntex
Posts: 66
Joined: Sat Jun 21, 2008 10:54 pm

RE: Sound Of Wind After Landing?

Wed Mar 25, 2009 10:11 pm

In addition to all of the other airports mentioned, at DCA you can certainly hear the vortices (at Gravelly Point park). It kind of threw me off the first time I heard it, but it's really a pretty cool sensation when you realize what's going on.
"The chief cause of failure and unhappiness is trading what you want most for what you want now." -Zig Ziglar

Who is online

Users browsing this forum: No registered users and 11 guests