MAI-60 Snezhinka

The Snezhinka was a prototype single seat, standard class (15 m (49 ft 3 in) wingspan) sailplane with a largely traditional wooden structure but with PVC foam filler strengthening.[1][2]

Its high aspect ratio, mid-set, straight tapered wings had a laminar aerofoil and were built around a single, wide box spar. This formed the central part of the wing between 25% and 65% of the chord. Its leading and trailing edges, covered with 1 mm (0.04 in) plywood skin, were supported internally with PVC foam. The tips had end plates. Narrow-chord ailerons occupied about 45% of the trailing edges and there were also airbrakes.[2]

The MAI-60's wooden fuselage was ply-skinned over stringers supported by bulkheads. Its cockpit was ahead of and over the wing leading edge, with its pilot in a semi-reclined seat under a single-piece, jettisonable canopy which ran smoothly into the raised rear fuselage. Aft, the fuselage tapered from below to a 90° butterfly tail with tetragonal fixed and control surfaces.[1][2]

There were tanks for 51 l (11 imp gal; 13 US gal) of water ballast.[2]

It landed on a central, semi-retractable monowheel aided by forward and tail skids.[1][2]

Testing over 1961-2 showed that the flight characteristics were poor, with directional instabilities and a need for large pitch inputs, and that its spin behaviour was unusual. There was also a structural problem caused by low strength glue, so the MAI-60 did not reach production.[2]

Data from j2mcPlaneurs[2] except where noted

General characteristics

• Crew: one
• Length: 5.0 m (16 ft 5 in)
• Wingspan: 15.0 m (49 ft 3 in)
• Height: 1.2 m (3 ft 11 in)
• Wing area: 10.7 m² (115 sq ft)
• Aspect ratio: 21
• Airfoil: NASA 663-618
• Empty weight: 210 kg (463 lb)
• Gross weight: 300 kg (661 lb) , without ballast[1]

Performance

• Maximum glide ratio: 33 best
• Rate of sink: 0.7 m/s (140 ft/min) minimum