School aircraft are sometimes overloaded during training, since they were never designed to take two large people and lots of fuel.
Whirly, you and quite a few others here seem to confuse W&B with MTOW. Two average sized adults and full fuel will put you slightly out of CofG (forward) on a PA28, however it will
NOT put you over MTOW.
In any case, relevant to this accident there are three distinct issues, which keep being conflated:
1) W&B
2) MTOW
3) TO performance
While all three are of course related, it would really help to keep them apart for the sake of this discussion.
On a different note, I am always flabbergasted by this idiotic
don't touch the mixture attitude. How many people in the UK are being taught how to lean for best power ???