These exist. Just pull the circuit breakers for the flight computers. The systems are isolated enough you can remove flight protections without losing flight co

These exist. Just pull the circuit breakers for the flight computers. The systems are isolated enough you can remove flight protections without losing flight controls. See https://en.m.wikipedia.org/wiki/Qantas_Flight_72 https://en.m.wikipedia.org/wiki/Qantas_Flight_72 for a flight computer failure. The Mayday episode lists states some time after that accident, another Qantas flight had the same failure, but the crew knew of the potential issue, so they cut power to all 3 flight computers.