Grob G102 Astir

{{Short description|German single-seat glider, 1974}} {{More citations needed|date=December 2012}}  {{Infobox aircraft |name=G102 Astir |image=astir.jpg |caption=Astir CS in flight |type=[[FAI Club Class|Club Class]] sailplane |national_origin=Germany |manufacturer=[[Grob Aircraft]] |designer=[[Burkhart Grob]] |first_flight=December 1974 |introduction=1975 |number_built=1241+ }}

[[File:Grob G 102 Standard Astir III N17999 20040514.jpg|right|thumb|Grob G 102 Standard Astir III N17999, National Air and Space Museum]] The '''G102 Astir''' is a single-seat [[glassfibre]] [[FAI Club Class|Club Class]] [[Glider (sailplane)|sailplane]], designed by [[Burkhart Grob]] and built by [[Grob Aircraft]]. It was the first Grob-designed sailplane, with the first flight in December 1974. Grob had previously built the [[Schempp-Hirth Standard Cirrus]] under licence.

==Design and development== The Astir CS [Club Standard] is of composite (fiberglass/resin) construction, has a large wing area, a T-tail and water ballast tanks in its wings. The large wing area gives good low-speed handling characteristics but its high-speed performance is inferior to other [[Glider competition classes#Standard Class|Standard Class]] gliders. In early versions, some of the fuselage frame was wood but this was replaced with a light alloy casting which sometimes cracked after heavy landings. The tail dolly is unusual by being a loose fit into a vertical hole and able to fall free if take-off is attempted with the dolly in place.

A slightly improved Standard Class version, the CS 77, was introduced in 1977. It has a different rudder profile and a slimmer fuselage similar to that of the Speed Astir. The Standard II and Standard III versions followed in the early 1980s, reverting to the higher-profile fuselage and with a reduced empty weight and an increased payload.

The Astir CS Jeans was similar to the CS 77, but had a fixed mainwheel and a tailskid. Its cockpit was fitted in blue denim. Later versions were the Club II and the Club III which also had fixed gear, but the Club III had a tailwheel.

The numbers built of each type were: 536 CS, 244 CS77, 248 CS Jeans, 61 Club/Standard Astir II and 152 Club/Standard Astir III. A flapped version called the [[Grob G 104 Speed Astir|G104 Speed Astir]] was also produced.

The latest in the Astir line is the '''G102 Standard Astir III''', designed by [[Burkhart Grob]] and built by [[Grob Aircraft]] as a development of the original G-102.

One Astir (now residing at the Steven F. Udvar-Hazy Center), flown by Robert Harris, broke the world absolute altitude record at 49,009 ft (14,938 m) on 17 February 1986. This record lasted until 2006.<ref>[http://records.fai.org/gliding/current.asp?id1=275&id2=1 List of official records] on the [[Fédération Aéronautique Internationale]] web site{{dead link|date=October 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

==Variants== ;Astir CS :The original production version of the Astir, produced up to 1977 (CS = Club Standard) ;Astir CS77 :Production aircraft from 1977, with revised fuselage profile and other modifications ;Speed Astir :The Astir with a flapped wing to comply with the FAI 15m Flapped Class, for gliding competitions ;Astir CS Jeans :Astir aircraft with faired fixed undercarriage, to comply with the Club Class for gliding competitions and to provide "glass-ship" experience at lower cost. ;G102 Astir :Designation introduced by Grob for the Astir series in the 1980s, with each successive improvement given the suffix I, II or III etc. ;G104 Speed Astir :The Speed Astir re-designated

==Specifications (Standard Astir III)== {{Aircraft specs |ref=[http://www.solidcad.hu/ass/GLIDING/LETOLTESEK_GLIDING/astir/grob102_flight_manual.pdf Grob G102 manual] |prime units?=met  |genhide= |crew=1 |capacity= |length m=6.75 |length ft= |length in= |length note= |span m=15.0 |span ft= |span in= |span note= |height m=1.26 |height ft= |height in= |height note= |wing area sqm=12.4 |wing area sqft= |wing area note= |aspect ratio=18.2 |airfoil= |empty weight kg=250 |empty weight lb= |empty weight note=approximately |gross weight kg=450 |gross weight lb= |gross weight note=with water ballast; without ballast 350 kg (770 lb) |max takeoff weight kg= |max takeoff weight lb= |max takeoff weight note= |more general=

|perfhide= |max speed kmh=170 |max speed mph= |max speed kts= |max speed note=manoeuvring and airtow |max speed mach= |cruise speed kmh= |cruise speed mph= |cruise speed kts= |cruise speed note= |stall speed kmh=59 |stall speed mph= |stall speed kts= |stall speed note=without airbrakes |never exceed speed kmh=250 |never exceed speed mph= |never exceed speed kts= |never exceed speed note= |minimum control speed kmh= |minimum control speed mph= |minimum control speed kts= |minimum control speed note= |range km= |range miles= |range nmi= |range note= |combat range km= |combat range miles= |combat range nmi= |combat range note= |ferry range km= |ferry range miles= |ferry range nmi= |ferry range note= |endurance= |ceiling m= |ceiling ft= |ceiling note= |g limits= |roll rate= |glide ratio=Best 38, at 105 km/h (64 mph, 56 kn) and 0.77 m/s (152 ft/m) |climb rate ms= |climb rate ftmin= |climb rate note= |time to altitude= |sink rate ms=0.62 |sink rate ftmin= |sink rate note=minimum, at 76 km/h (47 mph, 42 kn) and glide ratio 34 |lift to drag= |wing loading kg/m2= |wing loading lb/sqft= |wing loading note= |disk loading kg/m2= |disk loading lb/sqft= |disk loading note= |fuel consumption kg/km= |fuel consumption lb/mi= |power/mass= |thrust/weight= |more performance= |avionics= }}

==See also== {{aircontent  |see also= |related= *[[Grob G104 Speed Astir]] |similar aircraft= *[[Glasflügel 205 Club Libelle]] *[[Schleicher ASK 23]] *[[SZD-51 Junior]] |lists= *[[List of gliders]] }}

==References== {{Commons category|Grob G 102 Astir}} *[https://web.archive.org/web/20060926221015/http://www.sailplanedirectory.com/PlaneDetails.cfm?planeID=22 Sailplane Directory] *Hardy, M. ''Gliders & Sailplanes of the World''. Ian Allan, 1982 *[https://www.grob-aircraft.com Homepage of Grob Aircraft AG] {{reflist}}

[[Category:1970s German sailplanes]] [[Category:Grob aircraft]] [[Category:Aircraft first flown in 1974]] [[Category:T-tail aircraft]]