Considering the plummeting cost of small drones, eventually a search aircraft could drop one in the search area for it to search various areas perhaps with a datalink to the aircraft and then to an operator back at the base.
another scenario
plane spots wreckage/raft/survivors. Drop conditions are not safe/doable. A small drone could be dropped that flies to the site, acts as a beacon and has two way communications. It could also send video data back to the aircraft to assess the scene such any survivors, which would help determine what level of risk the SAR techs will take. If the drone can show that everyone is deceased, then parachuting might not be worth the risk when a recovery crew can walk 10 km from a place a helicopter can land or vis versa, survivors in desperate need of help means the risk of jumping is justified.