Depends on the size of the aircraft and the interior figuration
A small airplane can fit upto 4 passengers.
The original Wright Flyer held no passengers, only the pilot.
In a small airplane up to 3 passengers can be accommodated. This depends on the size of the plane. In small private jets up to 15 passengers can be accommodated.
The new Boeing 797 airplane was stated to hold 1000 passengers. This plane is not a real aircraft and information on its existence turn out to be a hoax .
Airport
A 747-400 with 3 classes of service holds about 416 passengers. With 2 classes of service it can hold 524 passengers.
Passengers sit in seats in the' fuselage' of the aircraft
The a380 can carry up to approximately 853 people
500
Safer airplanes
420
steward