Following the success of the Skyship 500 and AD500 series, and with the introduction of the Skyship 600 in 1984, it was decided to adapt the Skyship 500 to provide more lift, thereby increasing the ship’s versatility. It was decided to fit a Skyship 500 with a newer Skyship 600 envelope. The idea being that this would have the added advantage of some 30% more lift without any additional weight costs.
The first Skyship 500HL conversion was to SK500-04, which first flew successfully in March 1984. In all, a further five Skyship 500’s were converted to the HL format and flown. The first ship, registration G-SKS,C was based in Paris for local flights over the city
