Beware the Heavy. And any other aircraft for that matter. W.T.M.

[Farmboy]

WTM. Wake turbulence matters.

Few of you Supercub pilots will be operational at FL34 on an IFR vector, but I know a number of you fly something a mite bit heavier, or simply in the same airspace as those that do.

For this fellow, 1000 ft vertical separation wasn't enough for the Challenger 604 to handle the A380 wake turbulence. The passengers did not enjoy the 3 rolls or loss of 10k feet before bending the airplane.

http://avherald.com/h?article=4a5e80f3


Cautionary note from the report :
Considering the high operating air speeds in cruise, wake can be encountered up to 25 nautical miles (NM) behind the generating aeroplane, with the most significant encounters reported within a distance of 15 NM. This is larger than in approach or departure phases of flight.

 

[skywagon8a]

It sounds as though these people were extremely lucky in that the airplane was rendered not repairable.

 

[DavePA11]

Interesting article. surprised there was so much damage in the cabin. Photos at end of article...

 

[Farmboy]

Interesting article. surprised there was so much damage in the cabin. Photos at end of article...

At FL 34 in cruise everybody's relaxing and comfortable - don't have many seat belts on, six or something in the cabin? Sounds like they got thrown around pretty hard with the serious injuries.

A corporate flying friend of mine educated me a little bit about SLOP;

SLOP is strategic lateral offset procedure. It is one of the reasons that airways are 4 miles wide-if I physically saw an airplane like that flying over I would offset one or more miles to the upwind side to avoid its wake turbulence. Many people flying on the NAT tracks do that anyway because of RVSM airspace.


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[texmex]

A few questions.

What does W.T.M. stand for?

Is it normal to leave the zero off FL34? Took me a while to figure out what that was, particularly with vectors. I rarely get vectors at that altitude.

Thanks for the info on SLOP. There's a new prompt on the 78 FMC that I fly with SLOP. I've wondered what it stood for and as I'm leaving the A/C soon I haven't had the motivation to find an English manual on the subject.

Cheers. Texmex.

 

[Farmboy]

Texmex, most of your questions revolve around me just being sloppy in my post.

~ WTM was a play on a phrase for largely the american audience that has seen similar verbiage lately in the news. I used it to get the readers attention that Wake Turbulence Matters. As in, don't disregard it from any aircraft. (There's a very good video online showing tip vortices from an Anotov 2 that took out a Robin DR400)

~ No, it should be FL340 - I was being lazy.

~ SLOP I just learned about in discussion of this incident. But, another viewpoint on using SLOP at the time of "seeing the other aircraft" is that it would be too late at that point. You would have needed to anticipate the separation and remap your course miles ahead of it. I have no experience with any part of it.

Hope that clears it up for you.
Peter

 

[texmex]

Thanks for clarifying Peter. Why does it always seem obvious when someone tells you the answer?
I was genuinely scratching my head and not being cheeky.

Cheers. :smile:

 

[skywagon8a]

When you see the other aircraft it is a simple maneuver to just move a little to one side up wind or 100 feet above the other's wake to remain in smooth air. If there is a vapor trail behind the other plane, just stay out of it. SLOP

 

[SpainCub]

Thanks for the input!

You don't need to run into a A380 to have a serious problem...

On the cub, experienced something similar getting passed on from above and up wind from a C172, I lost 200ft. at we were at 8000ft, the pass was highly 100ft above my flight level... I lost several screws on the roo fairing and the metal gap seal of the aileron. :???: Apparently at 100h of PIC flying was not enough to learn my lesson, same airplane, got too close flying lower than the C172, and whoosh, here we go again. This time my input was ruder only and not aileron input to correct for the dropping wing, instinct was to get out of line of flight.

 

[mam90]

Good info on SLOP.

http://code7700.com/slop.htm

 

[skywagon8a]

Good info on SLOP.

http://code7700.com/slop.htm

Interesting that there has been something actually placed in print and under some circumstances authorized for use, a procedure which I have followed for decades without making it public. Starting during the days of visible exhaust smoke where it was easier to actually see the turbulent air behind the other aircraft I always moved a little bit in order to stay away from the wake turbulence. A little bit gives a smooth ride, doesn't violate any airspace parameters and is undetectable to controllers.

I recall one flight years ago headed west over the Rocky mountains at high altitude on a clear day. The airplane ahead of me on the same route, a Lockheed 1011, was continually complaining over the radio of the turbulent air. I never felt a bump in the same airspace and altitude. At the time I wondered what he was talking about. In fact he made so much talk of it on the radio, I made the comment that it was smooth where I was. He never said another word. Now this discussion reminds me of the incident. Perhaps he was riding in another's wake and did not SLOP?

 

[Eddie Foy]

We did the SLOP at AA flying non radar over the Amazon at night all the time.

Not for wake turbulence but for the guy coming at you at the same altitude.

Wasnt unusual to see an aircraft go by the other way with no TCAS target.

 

[mam90]

Yep. Notice that the procedure only allows specific offsets to the right of centerline due to the reduced separation standards which are now being used in remote airspace.

 

[skywagon8a]

The procedure calls for a 1 or 2 mile lateral offset. It's been a while for me, will the current on board equipment allow a few tenths of a mile offset or only whole miles? My "little bit" includes a 100 foot climb deviation while maintaining track. This would be virtually undetectable and within altimeter tolerances.

 

[Eddie Foy]

Wasnt any "procedure" when we did it. We would offset 1 mile right.

 

[mam90]

The new FMC's do allow tenth of a mile offsets, and there are some recent changes in certain areas of the world that are utilizing that. Now that ADS-C is so prevelant, you have to be aware that the aircraft is constantly transmitting position, altitude etc. to ATC. In RVSM airspace, a 100 ft altitude offset is probably not a viable option anymore.

 

[skywagon8a]

Wasnt any "procedure" when we did it. We would offset 1 mile right.

Makes sense as long as the opposing airline wasn't BOAC. They drive on the left side of the road. :roll:

 

[yellowbird69]

The smoke is a good depiction of wake turbulence---even with a "Hershey Bar" RV-8 wing---just "playing" with friends on a Fri night at Spruce Creek FL.----we even fly with "pinwheels"----don`t need any stinkin` SLOP----LOL---Capt Cub

 

[Farmboy]

John that looks like perfect strategic lateral offset to me.


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