Wake from a Ted Airbus

[Ralph Cramden]

Good 'ole ORD. Greatest controllers in the world who really know how to push the tin out of town. When I was flying there (Shorts, F27, Dash8 & CRJ) I got thumped almost daily. Most of the time it was crossing runway takeoffs which will get your attention but not too serious. Climbout following in trail wake was much more prevelant in the CRJ due to similar performance but the controllers have always accomodated me when I asked to parallel upwind on climb to get out of the rough. Just ask.

Now I'm in the A319. Don't think this is just a "little plane following big plane" problem. A 757 or 777 can give a wild ride when you are in their wake no matter what you fly. The bus is fly by wire joystick flown and will return to your set pitch & bank even when being hand flown. However fifi's response to the upset is quite slow and by the time she starts the recovery you have put in your own correction input and the fun begins. We call it "stirring the pot".

Just visualise the other guy's wake and try to stay above and/or upwind. The really fun stuff is on calm days with high humidity when you can actually see the vorticies bounce off the runway and back up at you when on short final following a big guy.

 

[chperplt]

No, they fly the glideslope in imc, so I will ask them why the difference is between vfr and imc

The difference is in the stabilized approach criteria your company has set up. You're probably violating that policy if you fly 1 dot high in IMC.

 

[OPECJet]

I've been hit with a bus wake on an arrival. Pretty big jolt.

I can't remember which RJ, but I got a hard 20 deg roll following one on an arrival as well. Apparently size doesn't matter.

Nice job with the recovery. Dam glad you're here telling the story.

 

[Cardinal]

This is just great. Guys in CRJ700s and A319s all flying "a dot high." What about the guy behind you (me) that weighs in at 1/5 of your MTOW?

So the 757 is flying a dot high for the 747 he's following. The A319 is flying two dots high for the 75's wake. The CRJ is three dots high to avoid the Airbii vortices, and the Beech behind 'em all will simply pitch twenty degrees nose up, point the thermal tiles at the earth, and reenter, space shuttle style, in a glowing cloud of plasma.

 

[low-key]

DFW was always a good time when they would launch you just as a Mad Dog was rotating, good wake ride from the 80. Hit by a 320 on T/O outta IAD a while back, another good wake ride. giddy up!

 

[248to2.8]

Flying in a Beech the other day I flew right through a NWA airbus wake. BAM! Kick it up a notch. As the passenger were getting off a couple asked what that was. Told them I think I hit a racoon.

 

[FlyChicaga]

This is just great. Guys in CRJ700s and A319s all flying "a dot high." What about the guy behind you (me) that weighs in at 1/5 of your MTOW?

So the 757 is flying a dot high for the 747 he's following. The A319 is flying two dots high for the 75's wake. The CRJ is three dots high to avoid the Airbii vortices, and the Beech behind 'em all will simply pitch twenty degrees nose up, point the thermal tiles at the earth, and reenter, space shuttle style, in a glowing cloud of plasma.

Hilarious, yet true. I've jumpseated on B737s where the crew flew 1/2 to 1 dot high behind a B777. That made me wonder what was going on behind if an RJ or turboprop was flying ON the glideslope.

I think training and knowledge in the physics of wake turbulence, as well as recovery techniques, is much more important than destabilizing an approach to try and avoid it. Unless you know for a fact the flightpath of the heavy in front of you, wake turbulence if often a mystery. It's invisible, dangerous, and it's location can't always be accurately predicted. I've been in the Saab at times when a B757 landed at MDW a little passed the touchdown zone. Should we have landed even farther past the touchdown zone on that 4925 ft rollout to avoid possible wake turbulence?

I'm usually more worried about it on departure. After all, "heavy, clean, and slow."

 

[MJG]

Funny thing is that the geniouses at NASA are now advising that we all "fly the glideslope like normal" instead of a dot high. Apparently their latest research indicates that there is no advantage to flying up a dot to avoid a previous aircraft's wake. Sorry I'm still not buying it. While I agree that it is difficult to predict where/when you might encounter someone's wake, I still feel better sitting a dot high.

Worst encounters I've had are behind the big 73's -800's and -900's. Those things should be given the same seperation as 757.