Wake turbulance question

[ScottK]

Watching this video got me to wondering. In some cases, the wake will curl around itself, yet on others, it will trail straight back from the aircraft. Is this the wing type/wind/? that causes this to be different?

I fly out of an airport that has Spirit A319s going in and out. I've run into some wake turb on approach a couple times, but never near the ground.

https://www.youtube.com/watch?v=dfY5ZQDzC5s&feature=youtu.be

 

[MAKG1]

Did you notice that the "straight back" ones come off the outboard end of the flaps (and they do curl over, but very tightly), and the "curling" ones come off the wingtips?

The landing at 2:40 shows both.

It's all about upward momentum at the outer edge.

 

[ScottK]

Thanks. I'll take another look.

 

[Rex Kramer]

BHX really needs to level that runway.

 

[Stewartb]

I've had lots of wake crossings at 90* from military traffic. C130s to C5 Galaxies and everything in between. 737 and 747 crossings at 45*, too. I'd characterize them as rolling turbulence. I had an F15 do a high performance turn in front of me once. That hit was hard and sharp. The decision to dive is balanced by maintaining some altitude for safety. Every situation is different. My own worst wake experience was in a C180 in trail of a C206 float plane. I got stuck in his wake. No control, just being sucked along in tow until I had presence of mind to go full throttle and climb a little, even though we were at the 1200' AGL airspace ceiling. That one got my attention. I never follow directly behind another airplane now.

 

[petrolero]

Those streamers are not the wake turbulence that you should be worried about (although I would avoid it like the plague too).

The clip that starts at about 1:35 shows both the streamers (caused by air bleeding & condensing around the sharp edge of the flap) and the actual wake vortices in the same frame.

The wake vortex is much larger than the little streamers and creates a very large swirl in the clouds at about 1:45. That is the serious stuff.

 

[woodchucker]

While still doing my PPL training we got hit by the wake turbulence from a pair of F-16s that passed overhead.... maybe a 1000 or so feet above us. My CFI mentioned that a buddy of his got hit by wake turbulence on final.... nearly put the plane 90* sideways.