Originally Posted by
mongo
a very slight change in the firmware of the multi rotor controller, or the auto stabilization system for fixed wing, would limit the baro altitude to a max of 400 ft over the initialization point.
no human error involved.
That would work, however it would only be a matter of time before the technology wizards would hack the code a post a "fix". Even DJI realizes that the airport database restriction will be hacked, probably already has. This stuff is not military grade electronics.