In aeroplane construction concepts for the installation of systems and concepts for freight loading systems are usually considered separately from one another.  Thus in the concepts of known art no interfaces exist between systems installation and the freight loading systems, although in both cases individual elements are to be conveyed and accurately arranged in position in an aeroplane fuselage. 
In a concept described in the applicant's patent application US 2008/0255026 A1 for the purpose of systems installation fuselage sections are each mounted on a conveyor vehicle and continuously moved in the transverse direction along a circuit from one build area to the next build area.  A comparable concept with a cyclical movement of the conveyor vehicles is also of known art. 
However, in these principles of assembly and/or installation of known art it is critical that the systems in question, such as runs and modules, also tools, accessories and small parts, must be individually moved into the fuselage by the assembly personnel to the installation site in question, which results in the expenditure of a large amount of time.  In addition the larger systems and tools require a high level of physical effort from the assembly personnel. 
Freight loading systems for cargo such as containers and items of luggage should enable the rapid loading and unloading of a freight compartment.  Furthermore the freight loading systems should only have a low weight and should enable an almost total utilisation of the freight compartment. 
A freight loading system of known art shown in DE 42 38 095 C2 envisages a conveyor belt extending in the longitudinal direction of the aeroplane, by means of which the cargo is conveyed into the freight compartment.  This freight loading system allows good utilisation of the freight compartment, but a very powerful drive is required for movement of the conveyor belt. 
Other freight loading systems envisage so-called roll mats, which are installed over a large surface area of the floor of the freight compartment.  The roll mats are, however, relatively heavy, and are susceptible to contamination. 
A freight loading system that can be compared with the roll mats is of known art from DE 603 11 544 T2.  In this system a multiplicity of ball- and roller-type actuating drives, arranged next to one another in the longitudinal and transverse directions of the aeroplane, are envisaged for the movement of the cargo.  The actuating drives are, however, susceptible to mechanical and electrical damage.  Furthermore loading and unloading is time-intensive. 
From the applicant's German patent application DE 199 23 529 A1 a freight loading system is of known art, in which the cargo is routed on rails extending in the longitudinal direction of the freight compartment.  While the loading and unloading times or freight loading times are indeed reduced relative to the solutions described earlier, the cargo during loading must be scheduled in a previously defined sequence on the rails, since no repositioning of the cargo is possible within the freight compartment.  Furthermore the cargo can only be introduced into the freight compartment through a front face side opening or rear face side opening, which limits the application of this freight loading system to freighter aeroplanes. 
The object of the present invention is to create a method and a device for the installation of systems or system modules in an aeroplane fuselage, which remove the above-cited disadvantages and enable a rapid installation, also a freight loading system with reduced freight loading times, which has features of the device for the installation of systems.