Redundancy plays a part, but it is not a major one. Major differences include the amount of scrutiny and government supervision in terms of inspections, certifi

Redundancy plays a part, but it is not a major one. Major differences include the amount of scrutiny and government supervision in terms of inspections, certifications, regulations, maintenance, traceability, medical checks etc. that commercial aviation requires and the difference in technology and support between a modern commercial airliner and the average general aviation plane.