The release can be activated in three ways: via a pull of a certain force for a length of
time, for example, 2kg for four seconds; via a 3.3V signal from the drone triggered
manually on the drone’s handheld controller; or via a 3.3V signal from the drone
triggered by the drone control software. The drone software can be programmed to
look for errors in flight behaviour, such as the payload swinging too much. The
operator that is watching the drone, meanwhile, can look out for problems the
software does not see. In all instances, the drone can return safely and the
waterproof sonar picked up later utilising a tracking signal.