The RFB X-114 Aerofoil Craft was an experimental ground-effect vehicle intended to work over water, with the ability to fly out of ground effect when required.

[4] Specifically, it is claimed that it is stable in pitch and also that it can fly in ground effect at altitudes up to about 50% of its span, allowing it to operate over rough water.

This contrasts with the lower aspect ratio square wing of the Ekranoplans, which leaves ground effect at only 10% of span, limiting them to the calmer waters of lakes and rivers.

A drive shaft ran rearwards from the engine within a conical fairing to a shrouded, five bladed pusher configuration propeller mounted near mid-chord.

Though Lippisch died just before the X-114 test programme began, his concept was further developed in the Airfish series of ground effect vehicles,[6] which continued in operation until at least 2012.