Why are two pilots needed to control most large aircraft?

Thank you for the A2A. If you see the crew complement of recent (in the last 50 years) commercial aircraft, you will see the numbers gradually coming down. read more

All later aircraft: the Airbus A300-600, the McDonnell-Douglas MD-11, the Boeing 747-400, the Airbus A340, and all subsequent big aircraft are now two-crew certificated. Two pilots were originally thought to be essential for safety; in course of time, airplane cockpits were designed to make use of two pilots for reducing pilot workload. read more

In this case, averaging is sensible. It will help smooth out noise in the control input. This is the principle behind the Autoland system for instance: it is an automatic landing system used on most large airliners that was trained on human pilot data from thousands of landings. It now lands better than most human pilots. read more

One small example re: Gulfstream. Has a tiller. In a crosswind, the right seat pilot will assist in applying crosswind correction as needed when left seat pilot's left hand is on tiller. Also, flight deck logistics: some switches/panels easier to reach from right seat. Generally, the aircraft's type certificate sets forth the minimum crew. read more