Loading system for passenger aircraft

A loading system for a vehicle 40 which may be an aircraft, comprising a passenger carrying module having passenger seats 14 mounted on a portable floor structure 10. The vehicle includes a loading aperture 48 shaped and dimensioned to receive a passenger carrying module and a closure means for closing the loading aperture. The loading aperture provides access to an internal compartment of the vehicle, the compartment receiving and retaining the passenger carrying module. Preferably the compartment is arranged to receive two or more of the passenger carrying modules and the compartment may also receive and retain a cargo carrying module. The module may be divided into one or more sub-compartment including one or more cabins 16 to store cargo. Preferable the module shell can be mounted on a ground vehicle 30.