Engineering:Kasper Bekas
| 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 United States mid-wing, tailless gliders designed by Witold Kasper and derived from the earlier 1959 Brochocki BKB-1 design.[1][2]
Design and development
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
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
- 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)
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
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Activate Media (2006). "Bekas 1-A Kasper". Archived from the original on 19 August 2012. https://web.archive.org/web/20120819215958/http://www.sailplanedirectory.com/PlaneDetails.cfm?PlaneID=37. Retrieved 26 April 2011.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Said, Bob: 1983 Sailplane Directory, Soaring Magazine, page 36. Soaring Society of America November 1983. USPS 499-920
- ↑ Federal Aviation Administration (April 2011). "Make / Model Inquiry Results". http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=1853. Retrieved 26 April 2011.
- ↑ Federal Aviation Administration (April 2011). "Make / Model Inquiry Results". http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=3654. Retrieved 26 April 2011.
External links
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