GEFA-FLUG cooperated with Thunder & Colt and developed the AS 80 GD and AS 105 GD thermal airships with a grant from the German government. The GD-series airships have a higher fineness ratio than the standard T&C models and thinner fins for better speed performance. The GD hot airships offer an advanced catenary load curtain system as well as a partial vertical partition of the envelope that allows to heat the front and bow of the ships independently for pitch control. As of September 1997, six GD-series hot airships had been built and serial numbers 7 and 8 were under construction.
