F3j - Thermal duration

Flying rules for F3J are quite straight-forward and require as much flight time as possible in a ten minute “slot” period ending with a precision landing.  The gliders are flown in groups (usually of between six and ten models at a time) so as to neutralise the effect of any one slot having nothing but “poor air” so resulting in nothing but low flight times for that slot.  The model should be landed close to a marked target spot to get landing bonus points.  In competitions, launching is generally accomplished in Australian events with a power winch but hand towing (150 metre line) is a requirement for international status events and two persons are allowed to tow. 

These two tow men generally use a pulley and stake and, by so doing, even more power can be injected into the model than from a power winch giving rise to quite spectacular launches.  Because the flyers believe that some of the group who will find thermal air to allow for a ten minute flight (and they can re-launch if they choose anyway), flyers will launch simultaneously at the start of the slot time; this gives a quite spectacular start to the slot and the landings, if multiple models fly out the ten minutes can be equally exciting.