[airplaneguy]

As some of you know already I am a Captain for a large National Airline. We (Captain or FO) routinely leave the Cockpit to use the lavatory during flight. We are required to have one of the Flight attendants come up and take our place when we leave. They are obviously not qualified to Fly the aircraft but they can open the door for the other pilot when he/she returns.

The type certificate of the planes require two pilots to operate in part 121 (Air Carrier) operation. So yes some silly regulation DOES require two pilots. If this happens then the First Officer automatically becomes the Pilot In Command(PIC) and any other pilots or Flight attendants work under them until landing.

Wombat101, you are right. there is too much to do for one pilot to do everything normally. Both pilots are qualified to fly and usually we trade off for each leg or every two legs. One guy flies and the other guy talks to air traffic control and coordinates things with the Flight attendants and Operations people.

[HiTech RedNeck]

SO, if there is no pilot among the passengers when the pilot or copilot becomes incapacitated, it becomes impossible to land the plane?

[conservatism_IS_compassion]

Flight attendants come up and take our place when we leave. They are obviously not qualified to Fly the aircraft but they can open the door for the other pilot when he/she returns.

. . . which raises the obvious question of how rare it is for a stew to have a private pilot's license.

And/or, to be given enough of an introduction to the cockpit to be as useful in an emergency as someone off the street who does.

[expatpat]

The small-plane pilot has to do both when flying IFR -- but I guess things happen faster at the higher speeds of airliners.