Schempp-Hirth Nimbus-2

From Wikipedia, the free encyclopedia

Schempp-Hirth Nimbus-2
Nimbus 2
Type designation Nimbus-2
Competition class Open
Number built 243 +
Crew 1
Length 7.28 m
7.33 m (after #45)
Height 1.45 m
Cockpit width 0.62 m
Cockpit height 0.80 m
Wingspan 20.30 m
Wing area 14.41 m²
Aspect ratio 28.6
Wing profile FX 67-K-170 / FX 67-K-150
Empty mass 345 kg (Nimbus-2 & 2b)
315 kg (Nimbus-2c)
appr 340 kg (Nimbus-2cs)
Water ballast 120-200 kg
Maximum mass 580 kg (Nimbus-2 & 2b)
650 kg (Nimbus-2c)
760 kg (Nimbus-2cs)
Wing loading 29 - 40.3 kg/m² (Nimbus-2 & 2b)
28 - 45.1 kg/m² (Nimbus-2c)
Maximum speed 270 km/h
Rough air speed 270 km/h
Minimum sink rate ca. 0.49 m/s
Best glide ratio ca. 47.5

The Schempp-Hirth Nimbus-2 is an Open Class glider built by Schempp-Hirth during the 1970s.

Loosely based on the original Nimbus HS-3 prototype, the production version that eventually surfaced as the Nimbus-2 was a very different glider with many improvements over the problematic prototype. The wing was shortened to 20.3 metres and was built in four sections to make it easier to rig and transport. It received Schempp-Hirth air brakes fitted in the upper surfaces and a tail braking-parachute, plus camber-changing flaps. It had an all-flying T-tail similar to the Standard Cirrus as well as the general layout of its fuselage.

The Nimbus-2 first flew in April 1971 and a total of over 240 examples of all subtypes have been built until the beginning of the 1980s. From serial number 130 on the Nimbus-2B was built with a fixed incidence horizontal tail to improve pitch control behaviour. The Nimbus-2C is a lighter variant with higher maximum certified flight mass, new trailing-edge combined airbrakes-flaps derived from the Glasflügel 303 Mosquito in place of the upper surface air brakes, and carbon-fibre wings and tailplane. Several other improvements took place during the production run without changes to the type designation.

A single example called Nimbus-2CS (serial number 192) was produced with reduced fuselage weight, an increased span of 23.5 m, an enlarged rudder and several other modifications. Seven examples of a self-launching version, the Nimbus-2M were built with a retractable engine. It is based on the Nimbus-2 (not 2b) but the wing is 15 cm further aft on the fuselage to make up for the C of G shift induced by the weight of the engine.

The Nimbus-2 was successful in competitions, twice winning the Open Class in World Gliding Championships: Göran Ax (Sweden) in 1972 and George Moffat (USA) in 1974. It was also popular with record-seekers. Bruce Lindsey Drake, David Napier Speight and Sholto Hamilton "Dick" Georgeson jointly set a World Goal and Free Distance record of 1,254 km in New Zealand in 1978, Doris Grove a feminine Out and Return record of 1,127 km in 1981, Yvonne Loader a feminine Height Gain record of 10212 m in 1988, and Joan Shaw a feminine Distance record of 951.43 km in 1990, all flying Nimbus-2. At it's time several national and world records were held by Nimbus-2M's in the FAI motorglider category. In 1979 Klaus Holighaus, the glider's designer, completed the first 1,000 km triangle in Germany flying a Nimbus-2.

The Nimbus-2 was succeeded by the Schempp-Hirth Nimbus-3.

[edit] Sources