FVA 10 "Theodor Bienen", FVA 10b "Rheinland"
Single seat glider             FVA 10
Single seat glider                 FVA 10b
Length 7,04 m, span 16 m, wing area 11,7 m2, aspect ratio 21,9, root chord
1,1 m, at tip 0,3 m, mean chord 0,73 m, width 0,55 m, frontal area 0,4 m2,
stabilizer 1,2 m2, elevator 0,6 m2, fin 0,8 m2, rudder 0,62 m2
Length 7,06 m
Empty 142 kg, max. flying weight 240 kg, wing load 20,5 kg/m2
Best gliding ratio 28 at 85 km/h, min sink 0,60 m/sec. at 60 km/h
Theodor Bienen
Built in 1936
Built in 1937, first flight over the Alps on 13/5 1937
The FVA-10a was a progressive development of the 'FVA-9' with a cantilever gull wing. The fuselage lines were smoothed and particular attention was paid to the wing fuselage junction. Initial tests were carried out at Merzbrück, in 1936, without a cockpit cover and testing continued at Prien where the canopy was completed. Performance of the FVA-10a was found to be excellent, fulfilling expectations. One built.
Design of a simplified and improved FVA-10 began in the autumn of 1936 with a new fuselage improvements to the wings and DFS airbrakes on top and bottom surfaces of the wings. The first flight was on 13 May 1937 with flight testing revealing the excellent performance which led to relative success in the 1937 International competition and the 1937 Rhön contest at the Wasserkuppe.
The type "FVA 10" was developed and built by the technical flying group of Aachen. The objects of this design were to attain a better speed, especially for cross-country flying, and improved maneuverability and stability at all speeds. Furthermore, the ship was designed so that three men, unaided, can unload and completely assemble it in five minutes. All of these requirements were satisfied in this completed design.
The full-cantilever, gulled mid-wing is in three parts; two panels and very large wing roots. These wing roots are built into the fuselage, thereby making possible a well streamlined unit. Assembly is very simple. Each wing is fitted to the root independently. This is done with only three bolts on each side which are fitted from the outside. Aileron and spoiler controls lock automatically without further adjusting. The wing form is tapered from both leading and trailing edges. The wing sections used from root to tip are: Jukowski 433, Goettingen 532 and USA M3. The construction is conventional with one spar and plywood leading edge. The spar has an I-scction. Spar gussets and assembly arc of the conventional German type (filler blocks for fittings, etc.) from the best grades of wood. The ailerons extend the full length of the wing panels beyond the gulled portion and are fitted on ball bearings. The controls are transmitted through a universal joint at the "gull" point.
Fittings are made from welded Aero 50 steel (Chrom-molyb). Spoilers to facilitate landing are installed on the upper surface of the wing and placed just inboard of the ailerons.   The fuselage form is such that at the best speeds the lifting currents cause the least drag possible. The forward part of the fuselage is lined internally with plywood, thus leaving an air space between. The cockpit is so arranged that the pilot's weight is comfortably resting from his knees to his neck. The cockpit cover was copied from the lines of a bat's head and constructed from steel tubing covered with pyralin. The tail of the fuselage is constructed in a curved and shaped circular form without bulkheads but with light stiffening rings.   Both rudder and elevator are dampened.
The rudder remains on the fuselage at all times but the elevator and stabilizer are removable by three easily accessible bolts. The FVA 10a, "Bienen", has wheel control, whereas the FVA 10b, 'Rheinland", has stick control. All controls are seated in ball bearings. Aileron movement is actuated through push rods and universal joints only; elevator through push rods and positive cables. Rudder pedals are adjustable without altering the length of rudder cables.
Because these ships are almost invariably launched by airplane tow by this group, the conventional skid was abandoned. In its place, a retractable single wheel landing gear was developed. It is pulled in through action on the shock struts. In the retracted position, one third of the wheel protrudes below the fuselage, which makes landings and ground maneuvering quite possible. Landing shock is absorbed through Flektron Co. shock struts. The wheel is an Iilek-
tron Co. 260 x 85 mm. tail wheel. In the three months that the FVA 10b has been in service, it has
flown more than 90 hours and has amassed almost 1300 miles in cross-country flights.