The problem with "flying anything" plans is that ground vehicles are pretty inherently stable with regards to most types of failures. Cutting or losing power so

The problem with "flying anything" plans is that ground vehicles are pretty inherently stable with regards to most types of failures. Cutting or losing power solves most problems. Not so with aircraft: any failure leaves the vehicle in a notably unsafe state - hence the delta between maintenance standards for road vehicles ("have brakes which work" basically) and aircraft.