When is it permitted to transfer a high power rocket motor to an uncertified person?

Transferring a high power rocket motor to an uncertified person is permitted when that individual is preparing to certify as a high power user. This situation implies that the individual is actively engaged in the certification process and is therefore deemed responsible enough to handle high power rocket motors. The certification process generally involves extensive training and understanding of safety protocols, which are crucial when dealing with high power rocketry that can pose significant risks if not handled correctly.

While completing a training course (the first option) might provide the necessary knowledge and skills, it does not necessarily indicate that the individual is actively pursuing certification. Witnessing a launch (the third option) may enhance understanding but does not provide the practical experience or authority needed to handle high power motors. The age requirement (the fourth option) also does not directly relate to the responsible handling of rocket motors; simply being over 21 does not assure the individual's knowledge or capability in managing high power rocketry equipment.