Akaflieg Braunschweig SB 8

Akaflieg Braunschweig SB 8
	f2
Type:	Glider
Design country:	Germany
Manufacturer:	Akaflieg Braunschweig
First flight:	April 25, 1967
Number of pieces:	2 prototypes

The SB 8 is a single-seat glider produced by Akaflieg Braunschweig . The first flight took place on April 25, 1967 at Braunschweig Airport .

history

The design of the SB 8 began in 1964 with the aim of creating a performance glider for the open class with low wing loading for the meteorological conditions of Central Europe. Since the aircraft was to be used within the club, it had to be easy for the pilot to handle; a comfortable seating position and good visibility were a high priority. A model on a scale of 1: 6.5 was measured in the large wind tunnel of the DFL and static load tests were carried out on a sample hull in 1967 and 1968 at the Institute for Aircraft and Lightweight Construction at the Technical University of Braunschweig . In mid-1966 the construction was completed and construction began, on April 25, 1967 the first flight of the SB 8 V1 with Helmut Driver followed.

A second copy was created due to its excellent flight characteristics and performance. The SB 8 V2 had a significantly stiffer and heavier wing, as the first one tended to flutter .

Flight performance measurements of the V1 were carried out in a comparison flight with the DLR - Cirrus in 1968 and 1991 in comparison with the DG-300/17 at the Idaflieg summer meeting in Aalen-Elchingen , and in 1968 with the SB 8 V2 in Braunschweig.

construction

The wings, fuselage and tail unit consisted of a full sandwich, which was used for the first time, with GRP on both sides of the balsa wood support material . The aircraft has 18 meters of spanning wings with a box spar (I-shaped outside), balsa ribs and a GRP torsion shell with balsa longitudinal strips. Each wing half has three drives for the flap and two for the aileron; Triple- bearing , double-decker brake flaps extend up and down. The connection of the two bars ending in the tongue and fork corresponds to that of SB 6 and SB 7 . The fuselage is strongly constricted behind the upright seated pilot. In the area of the fuselage-wing transition, the frames are made of pine plywood . A balsa fiberglass tube with Beulspanten wearing a T-tail with height and vertical tail . The rudder is covered with fabric. The large main wheel was retractable via a crank, chain drive and rope, later via bumpers.

use

After the flight tests, the SB 8 V1, D-6015, was used to determine deformations of the new composite material GRP during flight. The maximum torsion measured at a speed of 145 km / h with the flap position + 10 ° was 3.3 ° and the deflection at the edge curve was 10 cm downwards.

Sporting successes

5th place - German Gliding Championships Oerlinghausen 1968
1st place - Danish Championships in Arnborg 1969
1st place - Lower Saxony and Berlin gliding championships in Bückeburg 1970
2nd place - German Gliding Championships Bückeburg 1971
1st place - Romanian Gliding Championship Iash 1971

Technical specifications

Parameter	SB 8V1	SB 8V2
crew	1
Hull length	7.80 m	7.60 m
span	18.00 m
Vertical tail unit height	1.45 m	1.4 m
Wing area	14.1 m²
Wing extension	23
V position	1.5 °
Arrow	0 °
Wing profile	FX 62-K-153 mod. (inside) FX 62 K-131 (middle) FX 60-126 (outside)
Glide ratio	41 at 85 km / h
Slightest sinking	0.55 m / s at 75 km / h
Payload	105 kg	104/90 kg
Empty mass	220 kg	301 kg
Max. Takeoff mass	365/400 kg	405/490 kg
Wing loading	21.5-28.5 kg / m²	28.5-34.8 kg / m²
Top speed	200 km / h

literature

Academic Fliegergruppe Braunschweig (Ed.): SB 5 - SB 15 . Braunschweig glider. Appelhans-Verlag, Braunschweig 2012, ISBN 978-3-941737-73-0 , p. 79-112 .

Web links

SB 8 on akaflieg-braunschweig.de

Individual evidence

^ ^A ^b ^c ^d Academic Fliegergruppe Braunschweig [Hrsg.]: SB 5 - SB 15. Glider Braunschweig. 2nd Edition. Appelhans-Verlag, Braunschweig 2013, ISBN 978-3-941737-73-0 , pp. 79–112, 259f.
↑ Fred Thomas: Fundamentals of Sailplane Design. College Park Press, College Park 1999, ISBN 978-0-9669553-0-9 , p. 179.
^ Ralf Schneider: 75 years of Idaflieg - 1922–1997 . M. Wehle Verlag, Witterschlick / Bonn 1997, ISBN 3-89573-045-9 , p. 203 .
^ Georg Brütting: The most famous gliders . Motorbuch Verlag, Stuttgart 2003, ISBN 3-613-02296-6 , pp. 126-127.

[SB5–15-1] A ^b ^c ^d Academic Fliegergruppe Braunschweig [Hrsg.]: SB 5 - SB 15. Glider Braunschweig. 2nd Edition. Appelhans-Verlag, Braunschweig 2013, ISBN 978-3-941737-73-0 , pp. 79–112, 259f.

[2] Fred Thomas: Fundamentals of Sailplane Design. College Park Press, College Park 1999, ISBN 978-0-9669553-0-9 , p. 179.

[3] Ralf Schneider: 75 years of Idaflieg - 1922–1997 . M. Wehle Verlag, Witterschlick / Bonn 1997, ISBN 3-89573-045-9 , p. 203 .

[4] Georg Brütting: The most famous gliders . Motorbuch Verlag, Stuttgart 2003, ISBN 3-613-02296-6 , pp. 126-127.