"Chris" wrote in message
...
How do aircraft manufactures determine the maximum gross weight for a
given plane? I know I've come across articles that mention on a cool day
you can go over the max. gross weight by a percentage, I think 20% was
thrown out there but not sure. Then again, on a hot day you might not get
any where near that. Is it determined by a standard temp?

The manufacturers consider a number of factors. What can the structure
handle (don't forget the landing gear)? What weight gives decent takeoff
and climb performance on a hot day at a high altitude airport? What weight
gives the FAA mandated stall speed? Any of these issues (and more) can be
the limiting factor.

KB