Re: Wake of SuperJumbo

Date:         21 Jan 97 01:32:26 
From:         "L.M.N. Peiris" <lmnp1@eng.cam.ac.uk>
Organization: Cambridge University Engineering Department
References:   1
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Filip De Vos wrote:
>
> Would the wake of the next generation lage-scale civil transports be much
> worse to deal with than that of the actual large planes like the 747,
> A340?
> Recently a whole bunch of planes were reclassified to help determine
> minimum safe separation.
> Perhaps naively, I assume that a bigger A/C with a bigger wing, carrying
> more weight and having bigger engines will disturb more air?
>
> If that is indeed the case, then the airports visited by 747-600/700 or
> Airbus A3XX may see a capacity _reduction in the number of movements!

Obviously the larger planes would generate a stronger wake vortex due to
its larger wing dimensions and the downwash would be greater on approach
and landing compared to todays 747s.

However, a study conducted at Heathrow Airport in London has shown that
how long a wake vortex would last in the air depends on the weather
conditions, such as wind velocity, temperature gradients etc. Sometimes
they disappear very rapidly especially on windy days and sometimes they
remain for a long time particulary if the atmosphere is neutral. A 747
super jumbo may create a larger wake vortex than the existing 747s but
it would not significantly influence the movement capacity of the
airport.

Navin Peiris.
Cambridge University.

lmnp1@eng.cam.ac.uk