 RWD-9W had worse performance, comparing to RWD-9S (maximum speed 260 to 281 km/h).#

For research into Tricycle undercarriages D.W.L.converted the prototype RWD 9 to the RWD 20 fitting a 130 hp Walter Major engine, steerable noseleg, moving the main undercarriage legs rearwards, and removing the rear seats door and windows which were faired over with plywood.Extensive testing was carried out with take-offs, landings and taxiing on different surfaces including unprepared fields as well as ploughed land.