The expansion of the German aircraft industry from 1932 attracted several industrial concerns not previously involved in aviation.
Henschel, best known as locomotive builder was one; another, less familiar was the Ruhrtaler Maschinenfabrik Schwarz and Dyckerhoff who built small Diesel engined locomotives for underground use in the mining industry. They became involved in aviation through the enthusiasm of Hanns Schwarz, son of the founder of the firm. Around 1933, a manoeuvrable high performance single-seat advanced trainer was needed to train fighter pilots for combat.
Klemm had been approached but their work progressed very slowly despite the likely order for 180 aircraft. Meanwhile, Ruhrtaler had persuaded Willy Fiedler, a member of the
Stuttgart Akaflieg associated with
Stuttgart University, to spend a semester designing a competitor. Fiedler and Schwarz invited Tasso Proppe, experienced in glider building, to manage the new workshop. Schwarz himself took charge of the project after Fiedler's return to the Akaflieg and it was not until the autumn of 1936 that the Ru.3 made its first flight, piloted by Hanns Schwarz. Later, other pilots including Proppe and a commercial pilot named Trudel flew the aircraft, which they found fast and very manoeuvrable, as required for combat practice. On 1 November 1936 representatives of the Reich Air Ministry attended a demonstration of its capabilities. The morning session was a success but during an afternoon exhibition of the Ru.3's flight characteristics Schwarz got into a
spin and was killed. His father immediately cancelled all aeronautical activity in his firm. The contract for an advanced trainer had gone to the
Focke-Wulf Fw 56 after trials in 1935. The Ruhrtaler Ru.3 was a single engine,
parasol wing aircraft of mixed construction. Its one piece wing was built around a single wooden
spar, with a
plywood covering forward of it forming a torsion resistant box. Elsewhere the wing was
fabric covered. Broad, short
ailerons were hinged on an auxiliary spar and extended to the wing tips. In plan the
leading edge was swept back at about 9° but the
trailing edge was unswept. The tips were elliptical and there was a wide but shallow cut-out to assist the pilot's upward view. Its
fuselage was a steel tube lattice structure, largely fabric covered. Four
longerons formed an almost rectangular quadrilateral, with the upper side slightly wider than the underside. Its
Argus As 8B four cylinder inverted
inline engine was mounted on steel bearers attached to the forward end of the fuselage frame. It produced and drove a two blade
propeller. Its fuel tank was in the fuselage aft of the engine firewall. The wing was held a little above the fuselage by a short, outward leaning
lift strut on each side from the upper longerons to the wing spar and by further struts from the spar at the centre of the wing. The open cockpit placed the pilot on the line of the outer trailing edge, looking forward between wing and fuselage. Both upper and lower fuselage cross sections were rounded and the sides appeared faceted, shaped by stringers. The tapered
tailplane and vertical tail had straight edges and rounded tips, with the tailplane mounted at mid-fuselage height. Both
fin and
rudder were broad at the base, the latter extending to the keel and moving in a small
elevator cut-out. The Ru.3 had a fixed,
conventional undercarriage. The
spatted mainwheels were mounted on long
shock absorbing legs which leant inward to the upper longerons at the same points as the wing struts. Each axle was attached to a pair of V-struts, hinged on the fuselage underside and
faired in. There was also a small tailskid. The Ru.3 was unarmed but instead was fitted with a camera for recording success or otherwise in combat simulations with another aircraft. ==Specifications ==