Many (not all) training flights are booked as 1 hour slots - of which at least 10 minutes will be taken up by taxying and at the hold. So 50 minutes airborne is not ridiculously short - assuming that that includes a reasonable reserve so that the pilot can actually fly for 50 minutes rather than having to subtract a safety margin.
However if the aircraft is out of action for an hour after every flight to recharge, a flight school will need to have twice as many aircraft. Unless it can be fitted with a quick-change battery arrangement so that one set of batteries can be charging on the ground while the other set is flying.
Biting the hand that feeds IT
