Since we're talking electronic sensors...

"M" == Michael writes:

M The question was asked in another forum: why doesn't the
M aircraft have sensors in the landing gear so that it knows it's
M exact weight? It would also be able to calculate it's centre of
M gravity if such sensors were installed.

M Yes, I realise the genesis of this question has nothing to do
M with homebuilt aircraft BUT to my mind (having no electronic
M skills or experience whatsoever) this should be a trivial
M problem and if such a system were developed all aircraft,
M homebuilt and otherwise, would benefit. Besides, the people
M with the skills to tackle this problem reside in this newsgroup

Hmm, quite interesting and it should indeed be very feasible,
especially a trike. Glue some strain gages on each landing gear and
connect to the appropriate measurement device and A2D converter. Have
a cheap microprocessor convert the digital signal to weight on each
gear leg and display; calibrate once with a scale at a few different
weights (empty, gross, nose heavy, tail heavy). Quite the fun and
practical project.

--
It is a government of the people by the people for the people no
longer; it is a government of corporations by corporations for
corporations.
~ Rutherford B. Hayes