Ford has filed patents that describe technology to enable their drones to function as replacement sensors when an autonomous vehicle reports a broken sensor or two. The drone will land on the vehicle, connect to the data port, and function as a replacement sensor until the vehicle is repaired. The drone is summoned using a Vehicle-to-Vehicle network
https://www.c4isrnet.com/unmanned/2018/03/13/broken-navigation-system-put-a-drone-on-it/