Grob G104 Speed Astir

{{Short description|Competition sailplane built by Grob Aircraft, 1978}}  {{More footnotes|date=December 2012}} {{Infobox aircraft | name = G104 Speed Astir and Speed Astir II | logo = | logo_size = | image = Grob Speed Astir IIb.jpg | alt = | caption = Speed Astir IIb in flight | long_caption = | other_names = | aircraft_type = [[15 metre class]] sailplane | aim = | outcome = | related = | national_origin = Germany | manufacturer = [[Grob Aircraft]] | design_group = | designer = [[Burkhart Grob]] | builder = | issuer = | status = | owners = | primary_user = | more_users = | service = | major_applications = | proposals = | prototypes = | number_built = 108 | construction_number = | civil_registration = | military_serial = | radio_code = | requirement = | aircraft_carried = | flights = | total_hours = | total_distance = | construction_date = | introduction = | retired = | first_flight = April 1978 | initiated = | in_service = | last_flight = | expected = | developed_from = | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }}

The '''Grob G104 Speed Astir''' was a competition sailplane produced in Germany in the late 1970s as [[Grob Aircraft|Grob]]'s first design in the [[15 metre class]].

==Design and development== Taking the [[Grob G 102 Astir|G102 Astir]] design as a starting point, the Speed Astir featured a new wing of narrower chord and different section, a fin and rudder of reduced height, capacity for 150 kg (330 lb) of water ballast, and "elastic flaps". This latter feature eliminated the drag normally associated with the air gap between the wing and a deployed flap. It did this by extending the wing skin over the entire upper surface so the highly flexible skin served as the flap hinge and there was no air gap between the flap and the remainder of the wing.

The original Speed Astir flew in early 1978, but was replaced in production by the end of the year by a refined design named the '''Speed Astir II'''. This had a slimmer, laminar-flow fuselage and made use of carbon fibre in its construction. A version with a lengthened fuselage for taller pilots and incorporating carbon fibre wing spars was made available in 1979 as the '''IIB''', along with an increased-span version of the IIB as the '''II 17.5'''. Production of all variants was discontinued shortly thereafter.

==Specifications (Speed Astir II) == {{Aircraft specs |prime units? = met |crew=One pilot |length m=6.69 |length ft=21 |length in=11 |span m=15.00 |span ft=49 |span in=3 |height m=1.27 |height ft=4 |height in=2 |wing area sqm=11.5 |wing area sqft=124 |aspect ratio=19.6 |empty weight kg=265 |empty weight lb=584 |gross weight kg=515 |gross weight lb=1,135 |max speed kmh=270 |max speed mph=168 |glide ratio=41.5 |sink rate ms=0.6 |sink rate ftmin=120 }}

==See also== {{aircontent  |see also= |related= |similar aircraft= *[[Glaser-Dirks DG-200]] *[[Glasflügel Mosquito]] *[[Rolladen-Schneider LS3]] *[[Schempp-Hirth Mini-Nimbus]] |lists= *[[List of gliders]] }}

==References== {{commons category|Grob G 104 Speed Astir}} * {{cite book |last= Taylor |first= Michael J. H. |title=Jane's Encyclopedia of Aviation |year=1989 |publisher=Studio Editions |location=London |pages=441 }} * {{cite book |last= Hardy |first= Michael |title=Gliders and Sailplanes of the World |year=1982 |publisher=Ian Allan |location=Shepperton |pages=49–50 }}  * [http://www.grob-aircraft.com/ Homepage of Grob Aircraft]

[[Category:1970s German sailplanes]] [[Category:Grob aircraft]] [[Category:T-tail aircraft]] [[Category:Aircraft first flown in 1978]]