RFB X-113

The RFB X -113 was an experimental, designed by Alexander Lippisch ground effect aircraft, which was built at Rhein -Flugzeugbau.


X -113 based on the first draft Lippisch - ground-effect vehicle, the X- 112. Lippisch himself called the vehicle Aerofoilboot after the English word for airfoil. The X -112 (registration: N5961V ) was purchased from him in Cedar Rapids ( Iowa) designed and achieved in 1963 with a 18 kW (25 hp) while motor is a speed of 126 km / h

Lippisch developed the X -112 from 1959 to 1963 at the request of his former employer, Arthur Collins, owner of Collins Radio Company, which required a large, manufactured only from plastic motorboat in order to test its electronic instruments without interference. In model tests without built-in motor could be determined by means of a built- in leash scale that resistance only 4-5 % of the total weight scam, which corresponds to a glide ratio of 20 to 25.

After a lecture in 1965 in Bonn came the development of X -112 in Germany on interest, including the Federal Ministry of Defence and the Rhein -Flugzeugbau, who took over the production of the cell in a time very modern GRP construction. A second prototype was built with a 29 kW ( 40 hp ) engine in Germany in 1970 and as the X -113 (registration: D- 9568 ) respectively. The vehicle reached a top speed of 140 km / h In an interview Lippisch referred to such vehicle as " Flährzeug ", a mix of car and airplane.

Ground effect

To exploit the ground effect, "flies" the vehicle is about 20-40 cm above the water surface. The amount of air which supports the ground-effect vehicle consists then of two parts. One part is the accumulated air under the wings, this is moved mostly by boat. The smaller part of the air leaving the space under the wing, but is continually replaced by inflowing at the wing leading edge air. Thus, the main portion remains under the wing and generates there a pressure almost equal to the back pressure. The mass of air under the wing as it were forms a part of air, to the rolls such as the vehicle forward to a lubricant. For the effectiveness of the effect, especially the wing chord and the span is less authoritative. It also follows the boat, in contrast to the situation in an airplane, a virtually turbulence-free flow. Test results show that the existing manual control of the system is only briefly by durable. The human factor as a limitation of the system meant that the required ground effect flight performance was only briefly. Computer-aided control and regulation systems were not yet state of the art in aircraft at the time.


The cell was designed as GRP construction. The floating station has been made ​​of full - polystyrene core and the side walls of the central float in a foam - sandwich construction. RFB developed specifically for the structure for this boat a longitudinal tube - shell construction. All tubes are individually sealed and thus ensure the boat unsinkable even with stronger damage.


The only copy of the X -113 is currently available as a demonstration in the School of Engineering of Ngee Ann Polytechnic in Singapore.