Wake turbulence separation
 

Dear people,

I was looking for an official document stating the wake turbulence separation applied to a medium a/c behind a Boeing 757 on T/O and LDG. (official doc if possible)
I would like to know as well the official rule for the start of timing regarding wake turbulence separation on T/O, as some start timing at brake release and others at rotation of preceeding.

Many thanks for your inputs.
Regards

Elcapo

For the approach:

http://www.caa.co.uk/docs/33/CAP493PART1.PDF

Page 84, table at the bottom

Elcapo,

Be aware, the above is a UK publication. We treat the 757 as an 'upper medium', and not as a 'heavy' as many European states do.

Wrt the timing question:

Wake vortex on departure doesn't start until the aircraft rotates and the wings start to produce lift. Therefore the 2 minutes or whatever should start at that point. Many tower controllers will tell you that they are experienced in judging the issuing of take-off clearance so that the next aircraft will rotate as close as possible to 2 or 3 minutes (but not less) after the preceding one rotated.

Then there is the "Heathrow two minutes"...;)

Thanks for your replies so far. For the LDG it is pretty clear, as for the T/O not at all. I am F/O in a european company, during my ATPL I have been told to consider it as a heavy, but it changed since. Officially it is a medium type, so for LDG I found official docs, as for T/O not yet. Personally I am timing once the preceeding is starting to roll,as it will take me +- the same time to reach the rotation point. But it would be nice to find something written regarding that.

I think it's not that difficult, just hit your your timer when you see the preceding aircraft start moving and commence your take off 2 minutes later. I'm sure that's what the tower guys do, no? Granted the time from brakes off to rotation may vary but I'd say it would be negligable - maybe in the order of 10secs max?

Yes huckleberry, but I need an official statement, logically it is like that, but I am sure that it should be written somewhere. Thanks anyway.

Still waiting for some replies.

Thanks

in aussie
B757 is a heavy if it's the leading aircraft, and a medium if following an official heavy,
i think here it's 6nm/3min separation on radar and for arrival...
in AIP ENR section i can find the exact page if your question is inregard to aussie rules and regs

Wake Vortex
 

For a more in depth explanation of the UK situation,try http://www.chirp.co.uk/new/Downloads/pdfs/AIC17_99.pdf

B757 Vortex Separation
 

This also applies in Spain on Approach Control. Likewise, the vortex separation we provide between two B757' s is five miles on the localiser.