Koser KB-3 Jadran

The Koser KB-3 Jadran was a Slovenian amphibious sailplane designed and produced by LIBIS aircraft during Yugoslavian period. It was designed by Jaroslav Košer, a student at the Ljubljana Technical Faculty (Tehniška fakulteta v Ljubljani) of the University of Ljubljana and was a development of his earlier Koser-Hrovat KB-1 Triglav design.^[1][2][3]

Jadran
Role	Amphibious sailplane
National origin	Yugoslavia
Manufacturer	LIBIS aircraft
Designer	Jaroslav Košer
First flight	1949-50

Design and development

Specifications

Data from The World's sailplanes^[2]

General characteristics

• Crew: one
• Wingspan: 15.0 m (49 ft 3 in)
• Wing area: 13.25 m² (142.6 sq ft)
• Aspect ratio: 17
• Airfoil: Göttingen Gö 549
• Empty weight: 195 kg (430 lb)
• Gross weight: 280 kg (617 lb) maximum

Performance

• Maximum speed: 200 km/h (120 mph, 110 kn) placard
• Maximum glide ratio: 25 at 75 km/h (47 mph; 40 kn)
• Rate of sink: 0.75 m/s (148 ft/min) minimum, 60 km/h (37 mph; 32 kn)
• Aerotow maximum speed: 150 km/h (93 mph; 81 kn)