Rotter Nemere

M.Simons The World's Vintage Sailplanes 1908-45

THE NEMERE

  Lajos Rotter in Hungary had already had success with his strut-braced Karakan. For the 1936 Olympic Games meeting in Berlin he designed a new high performance type, the Nemere. The aircraft was constructed at the Royal Hungarian Aircraft Repair Works. When he began he had only seven months before the Staaken displays were due to take place. For aerobatics the sailplane had to be strong but he also wished to produce a superior cross-country aircraft. Rotter planned to convert the sailplane to a self-launching type, intending to fit a motor with pusher propeller mounted on a tripod above the centre section. This required extra strength to carry the additional load. He chose a span of 20 metres, used an aerofoil of his own design, and incorporated ailerons which could be drooped or raised as flaps, to widen the speed range. He aimed at a wing loading of 19 kg/sq m, and stressed the wings and tail to a factor of 12 g, instead of the usual 8. This necessitated a heavy, deep mainspar. The ailerons were broad, to ensure effectiveness. There were no airbrakes or spoilers, for in 1936 the need for such devices was only just beginning to be recognised.
  The fuselage was a fine streamlined form with fully contoured canopy and a ‘club’ shape to reduce skin drag over the rear part. The wings joined at shoulder level and were carefully faired. The cockpit was designed for comfort with the controls laid out readily to hand. The transparent, contoured canopy was framed in wood with panels of transparent plastic and large portholes for a clear view in rain. Venturi-driven gyro instruments were fitted. The tailplane was of the all-moving variety. The name, Nemere, came from the Transylvanian variety of the Foehn wind, a particularly dry, bitterly cold easterly. The aircraft was completed and test flown once, just in time to be despatched to Berlin by rail less than a week before the display on 4th August. After this all the sailplanes were aero-towed to Rangsdorf. Rotter was determined to go across country at the first opportunity and on 11th August he declared in advance that he would fly to Kiel, where the Olympic yachting was in progress, linking the two sections of the Games. Rotter packed his sandwiches and overnight bag into the Nemere. He retained the wheel dolly throughout, being afraid of landing out in some field far from help and being unable to move the heavy sailplane to safe shelter overnight if it was on its skid. The drag penalty would be quite large, for the wheels would spoil his glide ratio at high speeds. He got away, and made good progress. His course was north-west but the wind was easterly so each thermal he circled in saw him drifting off track and he had to make way across wind after each climb. He cruised between thermals, with ailerons trimmed up, at speeds between 120 and 140 km/h and often he flew straight ahead, slowly, through weak thermals, not bothering to circle in them. In the first hour he covered 89 km, in the next hour, 110. He came close to the lakes of the Schwerin area and slowed down, managing only 58 km in the third hour, but thermals were still available and he entered his last one within sight of his goal at Kiel. The aerodrome at which he proposed to land was near the harbor and he arrived with sufficient height to loop the loop several times in triumph over the yachting crowds before joining the circuit to land. He was feted by the Olympic officials.
  This flight proved to be the best made in Europe that year, and Rotter was awarded the first Gold Medal of the International Studienkommission fur den Segelflug (ISTUS). He had also set a new Hungarian National record. The Olympic Committee was greatly impressed and agreed that gliding should be included in the next Games, scheduled for 1940.
  The Nemere continued in service in Hungary. It was flown chiefly by Laszlo Tasnadi, a student of the Technical University and president of the student flying club. The sailplane's only other international appearance was at a competition in Poland in 1939, which was intended to devise suitable rules for the forthcoming Olympics planned for the following year.
  The Nemere, together with many other sailplanes, was hastily stored during the siege of Budapest which went on through the winter of 1944/45, and in the desperate times that followed, was neglected so that when at last there was a chance to revive the gliding movement, the Nemere, with most of the others, had deteriorated too far to be worth saving. Rotter's plan to fit the motor never materialised. In 1980 he was still living in Budapest.

  Technical data:
  Nemere: Span, 20.00 m. Wing area, 23 sq m. Aspect ratio, 17.39. Empty weight, 340 kg. Flying weight, 440 kg. Wing loading, 19.15 kg/sq m. Best glide, 1:26.