M.Simons The World's Vintage Sailplanes 1908-45
THE MOAZAGOTL
The Moazagotl was built by Edmund Schneider whose factory at Grunau in Silesia was very close to Hirschberg aerodrome where Wolf Hirth ran his gliding school. Local legends told of a peasant named Motz Gottlieb who paused frequently ДальшеMore>>>
in his ploughing to gaze skywards at a mysterious cloud which, in a southerly wind, often formed in the lee of the Riesengebirge ranges. In March 1933 Hirth had soared beneath this cloud in a Grunau Baby and afterwards correctly described the lift as being the result of a lee wave. His new sailplane was designed for cross-country thermal soaring, but he named it after the old peasant whose name in the story was corrupted to Moaza Gotl. At the 1933 Rhoen it distinguished itself by making the longest flight of the meeting and the next year it became only the second sailplane to fly 300 km.
It was large, but not exceptionally so for the period. The Obs and Austria were much larger. The Moazagotl's highly distinctive appearance set it aside. The wing was drafted by Dr Wenk, designer of the ill-fated Weltensegler of 1921. The sweepback on the outer panels of the wing, with centre of gravity well forward, ensured stability in pitch. The pronounced ‘gull' dihedral with flat, or even slightly drooping outer panels, was thought to improve stability in turns. The Moazagotl would fly ‘hands off' and circle smoothly in thermals.
The Goettingen 535 aerofoil at the root, continued to the bend in the wing, then the section changed progressively to run out into a thin, symmetrical form at the tip, with pronounced washout to ensure that the tips stalled after the wing roots.
The complex shape of the wing created some structural problems. The mainspar had to follow the ‘gull’ curve and this meant it had to be laminated from many thin strips of pine glued up on a curved form. To avoid having at the same time to bend this member backward for the sweep in plan, Wenk ran the mainspar straight to the root, which meant it had to become thinner inboard, as it came closer to the root leading edge. A large auxiliary diagonal spar helped take the torsional loads, but to resist the vertical bending moments a strut was necessary, the ends being very carefully faired to reduce interference drag. Hirth had realised that for cross-country flying it often helped to fly with a high wing loading and the new sailplane was fitted with a large tank, in the fuselage, to carry 50 kg of jettisonable water ballast. The Moazagotl was the first sailplane to be equipped in this way.
Blown plastic canopies were then unknown, but a semi-enclosed canopy was provided. It was made of plywood with two square ports on either side for vision to left and right, and there were transparent panels let into the front and top. It was not a fully transparent canopy, for there remained areas of plywood on each side and above. The pilot’s view was considerably restricted. A narrow neck or pylon supported the wing, and the fairing for this was extended back to the tail. Landings were on a normal skid with tennis ball springing, though a drop-off dolly was used for ground handling and aero-towed launches.
The tailplane was all-moving and was provided with a trimming device, probably a spring adjusted by the pilot since there was no trim tab. The rudder was aerodynamically balanced. A metal nosecap was fitted.
The Moazagotl flew in the 1937 Internationals, when Ludwig Hofmann placed second.
The Moazagotl survived in storage at Hirth's beautiful hilltop soaring site at the Hornberg in Wurttemberg to which he had moved his school. In 1945 as the Allied armies advanced into Germany, it was dragged out of the hangar and burned, to prevent its falling into enemy hands.
Technical data:
Moazagotl: Span, 20.00 m. Wing area, 20 sq m. Aspect ratio. 20. Empty weight. 190 kg. Flying weight, normal. 270 kg. with ballast. 320 kg. Wing loading, normal. 13.5 kg/sq m. with ballast. 16.0 kg sq m. Aerofoils, root, Goettingen 535, tip symmetrical, washout 8 degrees. Best glide ratio 23 : 1.
The Moazagotl at the launching point. The restricted view from the cockpit is evident. The louvred nose cap was probably for ventilation. Note the carefully faired strut end fittings, built out some way from the fuselage and wing surfaces to reduce interference drag.
The Moazagotl at the aerodrome near Grunau, apparently on the day of its first flight. Although still not quite complete, it was probably test flown in this configuration.
The Moazagotl partly completed, outside Edmund Schneider's factory at Grunau. Many details of the structure are evident. Edmund Schneider himself was in the picture, carrying the toolbox, but with his back to the camera.
The Moazagotl in flight, showing the graceful wing outline.
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