The availability of carbon fibre at affordable prices has allowed the manufacture of light and economical spans exceeding 15 metres. Manufacturers started to exploit this potential by offering tip extensions for their flapped sailplanes. Spans increased gradually from 16.6 metres in the first implementations (ASW 20L and Ventus b 16.6) to 17 metres (DG-200/17, DG-600, Glasflügel 403), 17.5 metres (LS6-c), finally settling on 18 metres. The trend towards turbo and self-launching sailplanes also favours the 18 metre span, which is large enough to carry the additional weight of the power unit without impairing the ability to climb in weak lift.