Re: United ad

From:         yyammine@aal2.iar.nrc.ca (Mattijs Janssens)
Organization: National Research Council of Canada
Date:         31 Aug 94 14:59:36 
References:   1
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> I recently noticed an ad for United Airlines (a propos of their employees'
> buyout) that depicted several hundred United workers standing around and
> atop a 747.
> ...

If my memory serves me correct FAR25 specifies load factors of +3.3 to -1.0,
meaning that the aircraft should be able to do inversed flight (n = -1.0)
without any (structural) damage.

For an estim. max mass of 400 tons the wings should thus be able to carry 
1.0*400 = 400,000 kg

With an avg. weight of 80 kg per person:

 400,000/80 = 5000 persons.

If the people are distributed acoording to normal lift distribution, i.e.
same number of people per chord length, there should be no problem with
bending moment as well.

However, forementioned estimation only goes for distributed forces. In case
of the wing the localized (footsize) weights of the people will be no 
problem (skinthickness is a few centimeters at the root of the wing, decreases
gradually). The fuselage however is a complete different story. Here the
skinthickness is something like 0.6 to 1.0 mm and this cannot support
a human being without (permanently) bending.

Mattijs Janssens