The decision to install inside the JET vacuum vessel a flight tube to allow Plasma High Field side injection of frozen fuelling pellets was only viable if the majority of work could be carried out remotely. The planned operations programme would be affected by the need to limit neutron production if all the work had to be carried out manually. The optimum route identified for the flight tube was through a Main Horizontal Port then, following the roof of the vessel, going behind a dump plate and inner restraint ring and finally exiting at approximately the mid plane on the vessel inboard side. The majority of the activities required had not been designed for remote handling nor was the detailed as built dimensional information (all features known to ~±0.5mm) available for this area of the vessel.