The Kasper Bekas is a family of American mid-wing, tailless gliders designed by Witold Kasper and derived from the earlier 1959 Brochocki BKB-1 design.^[1][2]

The Bekas series was an attempt by Kasper to create an experimental tailless glider with a higher glide ratio, better ground handling and rigging, using a flexible wing to study the effects of wing flexing on stability and controllability in flight.^[1][2]

The Bekas is built from wood and covered in plywood. The wing uses a NACA 8-H-12 airfoil and has greater span and higher aspect ratio than the BKB-1 to achieve its goals. The wing features outboard trailing edge control surfaces that act both as elevator for pitch control and aileron for roll control. The wing is swept 15° and has a chord of 38 in (97 cm). The landing gear is a fixed monowheel.^[1][2]

The design resulted in a high glide ratio for a 15 m (49.2 ft) wingspan of 45:1, along with a reasonably low sink rate of 2.0 feet per second.^[1][2]

The first Bekas, an "N" model, was built by Kasper in 1968. It was destroyed and removed from FAA records in 1977.^[3]

Two others were completed. One model 1-A was started by Al Wilson of Seattle, Washington and completed by Clifford Johnson of Minneapolis, Minnesota in 1972, which features a wider chord wing. The final one was completed by Don Mattson of Seattle.^[2][4]

Bekas N

The "N" (for narrow wing) was first flown in April 1968.^[2]

Bekas 1-A

Variant with longer wing chord.^[1][2]

Data from Sailplane Directory and Soaring^[1][2]

General characteristics

• Crew: one
• Length: 12 ft 0 in (3.66 m)
• Wingspan: 49 ft 3 in (15 m)
• Wing area: 158 sq ft (14.7 m²)
• Aspect ratio: 15.3
• Airfoil: NACA 8-H-12
• Empty weight: 350 lb (159 kg)
• Gross weight: 550 lb (249 kg)

Performance

• Maximum glide ratio: 45:1 at 66.5 mph (107 km/h)
• Rate of sink: 120 ft/min (0.61 m/s) at 50 mph (80 km/h)
• Wing loading: 3.48 lb/sq ft (17.0 kg/m²)

• List of gliders

• Photo of Kasper Bekas Archived March 23, 2012, at the Wayback Machine
• Photo of Kasper Bekas