Jump to content

Kasper Bekas

From Wikipedia, the free encyclopedia

Bekas series
Role Glider
National origin United States
Designer Witold Kasper
First flight April 1968
Introduction 1968
Status No longer in production
Number built 3
Developed from Brochocki BKB-1

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]

Design and development

[edit]

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]

Operational history

[edit]

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]

Variants

[edit]
Bekas N
The "N" (for narrow wing) was first flown in April 1968.[2]
Bekas 1-A
Variant with longer wing chord.[1][2]

Specifications (Bekas N)

[edit]

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)

See also

[edit]

References

[edit]
  1. ^ a b c d e f Activate Media (2006). "Bekas 1-A Kasper". Archived from the original on August 19, 2012. Retrieved April 26, 2011.
  2. ^ a b c d e f g h Said, Bob: 1983 Sailplane Directory, Soaring Magazine, page 36. Soaring Society of America November 1983. USPS 499-920
  3. ^ Federal Aviation Administration (April 2011). "Make / Model Inquiry Results". Retrieved April 26, 2011.
  4. ^ Federal Aviation Administration (April 2011). "Make / Model Inquiry Results". Retrieved April 26, 2011.
[edit]