wake turbulence - from small GA planes?

[briansommers 38]

I have ASE setup to give wake turbulence the problem though it gives it from any plane, not just big jets. is this realistic? I thought little planes can't give much off?

[NoahBryant 26]

Definitely not realistic, but I've experienced the same thing. I have even gotten it from a plane that was on a taxiway.

[briansommers 38]

ahh ok, that makes me feel better... it was really jerking me around. I guess I should take it down a good notch.

[Chock 12,449]

Small aircraft do kick off a fair bit of wake turbulence, although it depends on how fast they are going. I once had my glider flipped inverted by two Harrier jet fighters which passed either side of me in a combat spread when they did not see me, but they were doing about 450 knots by my reckoning. In fact, if you ever do a training course on aerotowing in a glider, one of the things you will be asked to do when in the glider, is to 'box the tow', which is where you go up on the tow, then slide out to the side, then down, then slide the other way, then back up, so you will have gone completely around the wake turbulence. When you are under it, you will probably be asked to stop and move up into the wake turbulence in order to experience where it is (which is quite a way below the tow aircraft), and you will feel it battering the tail fin and elevator and making the rudder pedals jitter around and the stick shake like a pre-stall buffet. That exercise is really about getting you to be able to stay in the right place on an aerotow without over-controlling as well as making you aware of how you have a responsibility to the tow pilot, but it does also show you how much turbulence there is 200 feet behind even a not very powerful glider tug. When I had to do it, it was behind a DeHavilland Chipmunk, which is not exactly the most powerful aircraft in the world LOL. Incidentally, if you want a flight sim which does a good job of it, this one has wake turbulence simulated in it. It's a bit old these days, but it's not a bad sim actually: http://uk.pc.ign.com...573/573218.html Al

[LAdamson 240]

We've made jokes about our real life RVs as being mini 757s. The 757 is famous for wake turbulence, and our RVs will easily want to start rolling a following plane, if you get in the wake. We're only talking 23 to 27' wing spans here. L.Adamson

[ZachLW 36]

Slow and "dirty" airfoils create the most wake turbulence, Al. You of all people know that!

[briansommers 38]

well its a bit frustrating what do you all have ASE wake turb. strength set at - I have mine at 100% - what would be more realistic setting. I wish you could set it for one setting for big jets and another for ga type planes.

[LAdamson 240]

Slow and "dirty" airfoils create the most wake turbulence, Al. You of all people know that!

I don't think the Boeing 757 would be classified as a slow and dirty airfoil. Van's RV airfoils are "turbulent" as opposed to laminar, yet the plane is fast for it's size and weight. L.Adamson

[Deaf Pilot 1]

Actually I have taken off as a flight of two in two Piper Arrows, and I was the wing man. On takeoff, I got behind the lead for a moment, and really got beat around - so small GA planes do create wake turbulence.

[ZachLW 36]

I don't think the Boeing 757 would be classified as a slow and dirty airfoil. Van's RV airfoils are "turbulent" as opposed to laminar, yet the plane is fast for it's size and weight. L.Adamson

I mean when the aircraft is *SLOW and DIRTY*. That's a frequently used term in aviation, so it's good to learn it. It means *Slow airspeed, lift devices/flaps deployed*. Takeoff, for instance, is a phase of flight when an aircraft is "slow and dirty". Landing too. I'm very familiar with the RV! I have a bit of time in an RV8.

Actually I have taken off as a flight of two in two Piper Arrows, and I was the wing man. On takeoff, I got behind the lead for a moment, and really got beat around - so small GA planes do create wake turbulence.

Of course they do! But ASE doesn't know the difference in right behind a GA aircraft and 2 minutes behind them.

[Cessnaflyer 56]

I don't think the Boeing 757 would be classified as a slow and dirty airfoil. Van's RV airfoils are "turbulent" as opposed to laminar, yet the plane is fast for it's size and weight. L.Adamson

He is saying when the aircraft is slow and the wing is dirty.

[briansommers 38]

Of course they do! But ASE doesn't know the difference in right behind a GA aircraft and 2 minutes behind them.

ahhh! that is what I was looking for... I didn't think it should have been as strong as it was.. I'm not sure what the best setting should be.. maybe just deal with it.. realistic or not..

[Great Ozzie 101]

Slow and "dirty" airfoils create the most wake turbulence

Slight correction... (aircraft) Heavy, Slow & Clean create the strongest vortex(es)

[ZachLW 36]

Slight correction... (aircraft) Heavy, Slow & Clean create the strongest vortex(es)

Yeah, you're right! Interesting point you bring up. But think about it. With the lift devices out, induced drag is higher. That's a key to wake turbulence. What makes the no flaps configuration more conducive to wake turbulence is the fact that the vortices roll more off of the wing tips. With flaps deployed, lift is created closer to the root. Therefore vortices will be less on the tips. Etc Etc. How often are 757s making slow approaches with no flaps?!

[Great Ozzie 101]

How often are 757s making slow approaches with no flaps?!

Personally I have a couple "incidents" with wake turbulence... not with the 757s. One involved a VC-25 flying a Low Approach into Purdue. Quite impressive as it floated what must have been about 50' above Rwy 28. The wake turbulence I witnessed it kick up was quite impressive too. Another with a 737 (I think... I was too busy flying the plane to worry about his "type") flying a missed on "old" 5L @ KIND while I was departing Rwy 32. This was back when 5L-23R & 14-32 intersected near the midpoints (old 5L-23R can still be seen on current diagrams X'd out). So not too many making flapless approaches... but missed's happen. Back to the OPs "Q"... no, I do not think the ASE is modeled precisely... mine is set quite low mainly for "convenience". That said, you will never get me to test "real world" wake turbulence as I have a healthy respect for what I have seen and what I have read regarding wake turbulence. I fly the profile recommended in the AIM (e.g. landing beyond the spot a heavier aircraft lands, departing from a point before the point they depart and avoiding flying below their climb profile). And as I just saw written in the AIM: "A wake encounter can be catastrophic. In 1972 at Fort Worth, Texas, a DC-9 got too close to a DC-10 (two miles back), rolled, caught a wingtip, and cartwheeled coming to rest in an inverted position on the runway. All aboard were killed." "The wake of larger aircraft requires the respect of all pilots."