Scheibe SF-27
{{Short description|German single-seat glider, 1964}}
| {{Infobox aircraft begin
| name=SF-27 Zugvogel V | image=Scheibe SF27 Glider LR.jpg | caption= }}{{Infobox aircraft type | type=Single seat Standard Class Sailplane | national origin=Germany | manufacturer=Scheibe-Flugzeugbau-gmbh, Dachau | designer= | first flight=12 May 1964 | introduced= | retired= | status= | primary user= | more users= | produced= | number built=about 120 | program cost= | unit cost= | developed from= Scheibe Zugvogel | variants with their own articles= }} |
The Scheibe SF-27 Zugvogel V ({{langx|en|Migratory Bird}}) is a single-seat Standard Class sailplane, designed and built in Germany in the 1960s. A motorised version was also produced. Significant numbers remain active.
Design and development
The SF-27 is a shoulder-wing, single-seat Standard Class sailplane, succeeding the Scheibe Zugvogel IIIB in production. It was designed to 1960s Standard Class competition rules requiring a span of no more than 15 m and a fixed undercarriage. Built of wood and steel, its structure was conservative; at a time when many manufacturers were using glassfibre structurally in wings and fuselages, the SF-27 only used it to cover the forward fuselage.
The wing of the SF-27 is built around a single beechwood boxspar, with plywood ribs and a leading edge torsion box. The wing covering is largely ply, entirely so over the outer section. The inner section is covered with ply from the leading-edge to behind the spar, the rest with a mixture of ply and fabric. Ailerons and Schempp-Hirth airbrakes are likewise ply covered. The cantilever horizontal tail is an all-moving ply and fabric-covered surface, set at the top of the fuselage; the fin is covered with ply and the rudder with fabric.
The fuselage is a welded steel structure covered, from nose to wing trailing edge, with a glassfibre shell. The wing root fairing is also glassfibre. Further aft the fuselage is fabric covered over wooden stringers. The cockpit, within the glassfibre shell, has a single piece Plexiglas canopy, the pilot sitting in a semi-reclined position. The SF-27 has a fixed monowheel undercarriage, fitted with brakes, plus a small tailwheel.
The SF-27 first flew on 12 May 1964. 30 had been built by February 1966, the final total being about 120. Scheibe also produced a motorised version, the SF-27M, with a 26 hp (19 kW) 4-cylinder Hirth F-102 A2 two stroke engine on a retractable mast above the wing behind the cockpit. Its gross weight is increased to 386 kg (850 lb) and it is {{convert|115|mm|in}} longer, with a best glide ratio 32:1.
Operational history
Variants
Specifications (SF-27A)
{{Aircraft specs
|ref=Jane's All the World's Aircraft 1966/7
|prime units?=met
|genhide=
|crew=1
|capacity=
|length m=7.05
|length ft=
|length in=
|length note=
|span m=15.0
|span ft=
|span in=
|span note=
|height m=
|height ft=
|height in=
|height note=
|wing area sqm=12.99
|wing area sqft=
|wing area note=
|aspect ratio=18.6
|airfoil=Wortmann FX 61-184 at root, FX 60-126 at tip
|empty weight kg=215
|empty weight lb=
|empty weight note=equipped
|max takeoff weight kg=330
|max takeoff weight lb=
|max takeoff weight note=
|fuel capacity=
|more general=
|perfhide=
|max speed kmh=
|max speed mph=
|max speed kts=
|max speed note=
|max speed mach=
|cruise speed kmh=
|cruise speed mph=
|cruise speed kts=
|cruise speed note=
|stall speed kmh=55
|stall speed mph=
|stall speed kts=
|stall speed note=
|never exceed speed kmh=
|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=34:1 at 88 km/h (55 mph)
|climb rate ms=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|sink rate ms=0.64
|sink rate ftmin=
|sink rate note=best, at 74 km/h (46 mph)
|lift to drag=
|wing loading kg/m2=
|wing loading lb/sqft=
|wing loading note=
|more performance=
|avionics=
}}
{{aircontent
|see also=
|related=
|similar aircraft=
|lists=
}}
References
{{commons category|Scheibe SF 27}}
;Notes
{{reflist|refs=
{{cite web |url= http://www.sf27.de/|title=List of SF-27s |access-date=2011-01-13}}
}}
;Bibliography
{{refbegin}}
- {{cite book |editor-last= Taylor|editor-first= John W.R. |title= Jane's All the World's Aircraft 1973-74|year= 1973|publisher= Jane's Yearbooks |location=London, United Kingdom|isbn=0-354-00117-5}}
{{refend}}
{{Scheibe aircraft}}
Category:1960s German sailplanes
Category:Shoulder-wing aircraft