the original speed astir flew in early 1978, but was replaced in production by the end of the year by a refined design named the speed astir ii. this had a slimmer, laminar-flow fuselage and made use of carbon fibre in its construction. a version with a lengthened fuselage for taller pilots and incorporating carbon fibre wing spars was made available in 1979 as the iib, along with an increased-span version of the iib as the ii 17.5. production of all variants was discontinued shortly thereafter.