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Grob G-104 Speed Astir II
 This single-seater Unrestricted 15m Class version of the Astir is generally similar to the Astir CS 77 except for wings of reduced area and different section, which have carbon-fibre spars and are fitted with so called 'elastic flaps' in which the gaps between the flap and the wing trailing edge are elastically sealed; these flaps can be deflected upwards to act as air brakes as well as downwards, and the ailerons can be drooped with the flaps.
The Speed Astir has the same cantilever mid-wing and T-tail as the Astir, but with a shorter fin and rudder and constructionally it is the same as its predecessor. The water ballast capacity has been increased to 330 lb.
After 25 of the original Speed Astirs had been built, production switched to the Speed Astir II which first flew on 11 November 1978.
This had a new and slimmer laminar flow fuselage, with carbon-fibre reinforcements in high stress areas, and a two-piece canopy, the rear section of which hinges to open aft. The tail unit is similar to that of the Astir CS but with shorter fin and rudder, and the new tailplane has a sealed elevator hinge line.
The slotless flaps extend half-way along the trailing edges, and the ailerons, which can be deflected in the same way, continue to the wingtips. Mounted on tracks and rollers, the ailerons and flaps articulate with the lower wing surface and can slightly increase the wing area. The wing upper surface features 'elastic' strips which form a permanent seal between flap and wing.
 Grob G-104 Speed Astir II
In October 1979 the cockpit was lengthened by nearly 8in to accommodate taller pilots, and the Speed Astir IIB has carbon-fibre spars. From the same date the Speed Astir II 17.5, a version with a longer span of 17.5m, was due to become available. Altogether 98 Speed Astir IIs had been built by December 1979 and the type is out of production.
 Speed Astir II
G 104 Speed Astir II & IIb
Wing span: 15m / 49 ft 2.5 in
Wing area: 11.46 sq.m / 123.4 sq.ft
Length: 21 ft 11.25 in
Height: 4 ft 2 in
Empty Weight: 265 kg / 584 lb
Payload: 250 kg / 551 lb
Gross Weight: 515 kg / 1135 lb
Wing Load: 44.94 kg/sq.m / 9.19 lb/sq.ft
Water Ballast: 140 kg / 308 lb
Max speed:168 mph (smooth air)
MinSink: 0.70 m/s / 2.3 fps / 1.36 kt at 47mph
L/DMax: 40 95 kph / 52 kt / 60 mph
Best glide ratio: 41.5:1 at 74.5 mph
Aspect ratio: 19.6
Airfoil: Eppler E 662
Seats: 1
No. Built: 107
Speed Astir II
Wing span: 15.0 m / 49 ft 2.5 in
Length: 6.60 m / 21 ft 8 in
Height: 1.27 m / 4 ft 2 in
Wing area: 11.5 sq.m / 124.8 sq ft
Wing section: Eppler E660
Aspect ratio: 19.6
Empty weight: 250 kg / 551 lb
Max weight: 515 kg / 1,134 lb
Water ballast: 180 kg / 397 lb
Max wing loading: 45 kg/sq.m / 9.2 lb/sq ft
Max speed: 146 kt / 270 km/h
Stalling speed: 35 kt / 64 km/h
Min sinking speed: 0.57m/sec / 1.87 ft/sec at 40 kt / 75 km/h
Best glide ratio: 41.5 at 65 kt / 120 km/h
 Speed Astir II
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