Depends on the drone... The Pixhawk controller (that many of us from the RC / tech community use) can record so much data that it can be overwhelming. The com

Depends on the drone... The Pixhawk controller (that many of us from the RC / tech community use) can record so much data that it can be overwhelming. The commercial 3D Robotics SOLO uses an updated version of the same controller, and has such data logging enabled continuously. In fact, it -also- streams it continuously to its controller unit; even if you lose the drone there will be enough data in the controller to figure out what happened. 3DR uses that to back their flyaway warranty (if a SOLO flys away or crashes due to a software/hardware fault vs user error, 3DR will replace the entire thing free) (I'm not affiliated with 3DR other than owning a Pixhawk.)