Vans RV-4Vans RV 4 airplane model. The RV 4 was a development of the single seat RV 3 and was also designed by Richard Van Grunsven of Oregon, USA. It seated two in tandem and was similar in external appearance to the RV 3 but was some 20% larger. There was no commonality of airframe components, the design goal being only to retain the flight characteristics and overall performance of the RV 3. The prototype of the RV 4 (N14RV) was first flown on 21 August