Can a passenger sit in a flight attendant jumpseat for takeoff and landing instead of their assigned seat in the cabin?
There are a couple of regulations involved, and ultimately the answer is no, a passenger cannot sit in a flight attendant jumpseat for takeoff and landing under normal circumstances. For starters, airlines cannot sell unoccupied flight attendant jumpseat positions to passengers. Some might ask, “why not?” It has to do with the certification of the aircraft, mentioned below.
14 CFR 121.391 Flight Attendants addresses flight attendant staffing requirements.
The flight attendant staffing requirements are based upon the seating capacity (installed seats) of the aircraft. The seating capacity doesn’t consider flight attendant jumpseats as passenger seats.
There’s also 121.311 (g) Seats, safety belts, and shoulder harnesses. This section defines the requirements of flight attendant jumpseats, and (g)(3) also mentions requirements that do not apply to passenger seats. It’s clear that each seat has a designation for use, one type for passengers, and another for flight attendants.
When the airline performed its certification demonstration of the aircraft, passengers were only in passenger seats; the certification demonstration and approval was made upon that premise that crewmembers are in flight attendant jumpseats, and passengers in passenger seats.