Originally Posted by
Intercepted
I also managed to convince a CFI once that we didn't need to have 50 liter of water in the back seat of a PA28 to stay within CG limit during a test.
I have to ask when was the last time the aircraft was accurately weighed ? I bring this up because small errors do accumulate during and after the weighing process. I still think fussing over seat position is ultimately as meaningless as those elaborate PLOGs which result in fuel burns calulated to the tenth of of a gallon.
if you want to put seat position into your W & B calculations there is no reason not to, just understand that for all but the most unusual loading situations it will not have any practical effect. To imply that it is negligent not to use seat position in every calculation is an idea which I think you will find is not supported by very many people.
In any case for the same reason one should assume greater than book fuel flows and slower than book cruise speeds for cross country planning, loading to the exact limit (especially the aft limit) is to place an unwarrented faith in the absolute accuracy of the aircraft data ( in this case the aircraft empty weight and moment), and should IMO therefore be avoided.