There is growing interest in the use of drones by utility companies to patrol overhead lines and look for damage, hot spots and other problems.
Also to check railway lines in places liable to landslides, rockfalls, subsidence, and trees coming down.

If life was at risk such drones could be repurposed to help in searches.

Machine vision and artificial intelligence are progressing to the point where drones used for routine inspection purposes, could notice persons in trouble and report or investigate this.

Persons in trouble have been seen by pilots of aircraft on routine flights, not specifically engaged in searching. It wont be long until drones can recognise persons in trouble.

In Australia, (and presumably elsewhere) lives have been lost on remote roads due to mechanical breakdown and then running out of water before anyone realises.
To reduce the risks, police officers patrol some such roads once a week, and persons driving in such places are warned to carry drinking water for at least a week.
Most such patrols of course find nothing whatsoever, and the skilled and expensive time of two police officers and vehicle is thereby taken up.
Consider the benefits of patrolling by drone instead ! Much cheaper for a start. Despite the advances in machine vision/AI the images would probably have to monitored by a human, but this could be done at much lower cost than two policemen and a car.
Useful employment perhaps for someone physically disabled, but mentally alert.