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Grob G.102 Astir



The G-102 Astir is a single seat glassfibre Standard Class sailplane, designed by Burkhart Grob. It was the first Grob-designed sailplane.
Construction of the prototype Astir CS began in March 1974. It features composite (fiberglass/resin) construction, a large wing area, a T-tail and water ballast. A Standard Class Sailplane, the large wing area gives good low speed handling characteristics. The main gear retracts. It first flew on 19 December 1974 and it went into production in July 1975 and soon proved to be popular, a total of 534 being delivered.
The cantilever mid wings have glassfibre roving main spars and a glassfibre/epoxy resin sandwich skin except for the ailerons, which are of glassfibre sandwich. There are Schempp-Hirth aluminium air brakes in the wing upper surfaces, but no flaps, and up to 220lb of water ballast can be carried in tanks in the wings, being jettisoned via a dump valve in the fuselage. Rigging is carried out without any separate removable parts as the wings and the tailplane are attached by a system of 'snaplock' connectors. The glassfibre semi-monocoque fuselage has a towing/launching hook, and the large one-piece cockpit canopy opens sideways to starboard.
Construction of the T-tail unit is the same as that of the wings.
This was followed by the Club II with similar fixed gear. A slightly improved version, the CS-77, was introduced in 1977. The CS-77 has a different rudder profile fuselage similar to that of the Speed Astir. The Astir CS 77 made its first flight on 26 March 1977; nearly 400 of the CS 77 and Club Astir had been built by the end of 1978.
The Club Astir II and the Standard Astir II featured the new fuselage of the Speed Astir II. with a one piece canopy, as well as the elasticated flaps of the Speed version and a new wing tip profile.
The Astir CS 77 has a retractable monowheel with an internally-expanding drum brake located ahead of the center of gravity, which folds up behind closed doors, and there is also a rubber-sprung tail wheel. The Astir CSM was a powered version under development in mid-1976 with a 25hp Fichtel & Sachs Wankel KM24 rotating piston engine on a retractable pylon aft of the pilot, driving a two-blade Hoffman tractor propeller. A 6.6 gal fuel tank is fitted.
G-102 Astir


The Astir CS Jeans was of similar configuration to the CS 77, but with fixed wheel, and a tailskid.
The Standard III followed in the early 1980’s reverting to the higher profile fuselage and with reduced empty weight and increased payload. The Club III has a fixed main gear ahead of the center of gravity, and a tailwheel. The Club IIIB has a cockpit almost identical to the front seat of the two-place G 103 Twin II with a fixed main gear aft of the center of gravity and a nosewheel. Air Transport Certified (except Club II which is EXP). One, flown by R.R. Harris of the U.S., won the world absolute altitude record at 14.938 m/ 49.009 ft in 1986.
Production variants were the Club Astir III, IIIB and Standard Astir III, which have a roomier cockpit and reduced empty weight.
Grob G-102 Astir CS77 ZK-GMA


Grob 102
Wingspan: 15.00 m (49 ft 3 in)
Wing area: 12.4 sq.m (133 sq.ft)
Water ballast: 50 kg (110 lb)
Aspect ratio: 18.2
Empty weight: 255 kg (561 lb)
Gross weight: 450 kg (990 lb)
Maximum glide ratio: 38
Glide Ratio: 36 at 50 kt (92 km/h) / 5.9 nm (10.97 km) per 1000 ft
Sink rate: 141 ft/min (0.71 m/s) at 50 kt
Glide Ratio: 34 at 41 kt (76 km/h) / 5.6 nm (10.36 km) per 1000 ft
Sink rate: 122 ft/min (0.62 m/s) at 41 kt
At 90 knots (166 km/h)
Glide Ratio: 23 at 90 kt (166 km/h) / 3.8 nm (7.01 km) per 1000 ft
Sink rate: 393 ft/min (2.00 m/s) at 90 kt
Stall: (without airbrakes) 32 knots (60 km/h)
Stall: (with airbrakes) 35 knots (65 km/h)
Never Exceed: 135 knots (250 km/h)
In Rough Air: 135 knots (250 km/h)
Manoeuvering: 92 knots (170 km/h)
On Aerotow: 92 knots (170 km/h)
On Winch: 64 knots (120 km/h)
Airbrakes: 135 knots (250 km/h)
Gear Down: 135 knots (250 km/h)
Minimum Payload: 70 kg
Maximum Payload: 110 kg
Crew: One pilot

Astir CS Jeans
Wing span: 15m / 49.2ft
Wing area: 12.4sq.m / 133.5sq.ft
Empty Weight: 248kg / 547lb
Payload: 132kg / 291lb
Gross Weight: 380kg / 838lb
Wing Load: 30.64kg/sq.m / 6.27lb/sq.ft
Water Ballast: 0
Aspect ratio: 18.2
L/DMax: 33.3 93 kph / 50 kt / 58 mph
MinSink: 0.70 m/s / 2.3 fps / 1.36 kt
Airfoil: Eppler E 603
Seats: 1
No. Built: 337

G 102 Astir CS
Wing span: 15m / 49.2ft
Wing area: 12.4sq.m / 133.5sq.ft
Empty Weight: 255kg / 562lb
Payload: 195kg / 430lb
Gross Weight: 450kg / 992lb
Wing Load: 36.92kg/sq.m / 7.43lb/sq.ft
Water Ballast: 0
Aspect ratio: 18.2
Airfoil: Eppler E 603
L/DMax: 38 105 kph / 56 kt / 65 mph
MinSink: 0.70 m/s / 2.3 fps / 1.36 kt
Seats: 1
No. Built: 864


Grob G-102 Astir CS77
Span: 49 ft 2.5 in / 15.0 m
Length: 21 ft 11.25 in / 6.69 m
Height: 4 ft 7 in / 1.4 m
Wing area: 133.5 sq.ft / 12.4 sq.m
Aspect ratio: 18.2
Wing section: Eppler E603
Empty weight: 595 lb / 270 kg
Max weight: 992 lb / 450 kg
Water ballast: (220 lb / 100 kg
Max wing loading: 7.43 lb/sq ft /36.3 kg/sq.m
Max speed: 155 mph / 135 kt / 250 km/h
Stalling speed: 32.5 kt / 60 km/h
Max aero-tow speed: 105 mph
Max rough air speed: 135 kt / 250 km/h
Min sinking speed: 0.6 m/sec / 1.97 ft/sec at 47 mph / 40.5 kt / 75 km/h

Best glide ratio: 38:1 at 65 mph / 56.5 kt / 105 km/h












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