Re: B757 "Heavy Jet"?

From: (JD Jacob)
Organization: UC Berkeley
Date:         24 Jun 96 00:42:05 
References:   1
Followups:    1
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In article <airliners.1996.946@ohare.Chicago.COM>,
 <> wrote:
>    Hello I was wondering if someone can help me understanding why the
>FAA decreed the 757 as a Heavy Jet.
>I know it fits the Cat. just by using its weight, but if I'm not
>mistaken that was not the reason behind the ruling.
>Thank you ...... Mooney1

Due to the strength of its vortex wake. Before the advent of the
jumbos (747 and the like) there were only two categories, small and
large, generally split into general aviation and airliners, respectively.
The 757 is a borderline plane, falling into the large category just
barely, IIRC. It has a high wing loading and strong wake, however, and
since the category sets the separation distance between leading and
following aircraft, it was bumped up after a few incidents.

J.D. Jacob                                    Post-Doctoral Fellow, UCB-FML
140 Hesse Hall, Dept. of Mechanical Eng., U.C. Berkeley, Berkeley, CA 94720                           "Nam et ipsa scienta                         potestas est."