it says "no person shall" innumerable times-in the relevant FARS on
WAT limits...
Of course it does -- in the
operating regulations.
However FAR 25 is not an
operating regulation -- rather it defines certification standards to Boeing, Embraer, Airbus, etc. Describes minimum flight paths for flight test engineers who are compiling data for AFM.
The
operating rules such as 121.189 tell "persons" how the AFM data must be applied to determine maximum takeoff weight for that aircraft for the specified runway and obstacle environment.
AC 120-91 provides guidance for compliance with 121.189 et al.
Isn't that what j_t and FpOBN were saying -- that there's a difference between
Design standards and
Operating Rules?