TeST TST-14 Bonus

The TeST TST-14 Bonus is a Czech high-wing, T-tailed, two-seats-in-tandem glider and motor glider, designed and produced by TeST Gliders.^[1][2][3]

TST-14 Bonus
Frontal view
Role	Glider and Motor glider
National origin	Czech Republic
Manufacturer	TeST Gliders
Introduction	2001
Status	Produced until 2010
Number built	About 50
Variants	TeST TST-14J BonusJet

Design and development

General view with engine

three view diagram

longitudinal section

U.S.A. Certification

French Certification

Czech Rep. Certification

Polar

flight envelope

engine installation and wooden propeller

Landing on a grass runway

In flight

Lateral view

Bonus assembly

The TST-14 motor glider was designed for private owner and flying school use and as such features wing tip wheels that allow independent taxiing and take-off.^[1][3]

The TST-14 is constructed from composite materials, with the forward-swept wing a ribless composite sandwich structure. Each wing weighs 40 kg (88 lb) and has a single spar made with a carbon fibre composite flange plate and a polyurethane foam/fibreglass composite web plate. Glidepath control is by upper surface air brakes made from aluminium. The motor glider version is powered by a retractable 50 hp (37 kW) Rotax 503UL two-stroke powerlant. Extension and retraction of the engine is fully automatic, controlled with two cockpit-mounted buttons and actuated by two electric servo motors. The landing gear consists of dual fuselage-mounted tandem mainwheels and wing tip-mounted wheels.^[1][4][5]

The aircraft was type certified to the Joint Aviation Authorities JAR 22 standard for gliders on 10 Dec 2001. The TST-14 was not certified in the United States as the company explains, "due to the expense involved". The aircraft can be registered with the US Federal Aviation Administration as a Special Light Sport Aircraft glider or in the Experimental - racing/exhibition category.^[2][5][6]

Variants

TST-14 Bonus

Pure glider version, with a gross weight of 472.5 kg (1,042 lb)^[3]

TST-14M

Main production motor glider version, powered by a 50 hp (37 kW) Rotax 503UL two-stroke double ignition powerlant^[1]

Specifications (TST-14M Bonus)

Data from Sailplane Directory and company website^[1][4][5]

General characteristics

• Crew: one
• Capacity: one passenger
• Length: 8.24 m (27 ft 0 in)
• Wingspan: 17 m (55 ft 9 in)
• Height: 1.10 m (3 ft 7 in) of passenger cabin, tail Is higher
• Wing area: 12.01 m² (129.3 sq ft)
• Aspect ratio: 23.92:1
• Airfoil: Wortmann modified
• Empty weight: 280 kg (617 lb) 300 kg if present ballistic parachute
• Gross weight: 450 kg (992 lb) 472 kg if present ballistic parachute
• Max takeoff weight: 450 kg (992 lb) 472.5 if present a ballistic parachute
• Fuel capacity: 22.6 litres (5.0 imp gal; 6.0 US gal) approximately 2.5 hours of flight, if the engine is always on
• Powerplant: 1 × Rotax 503UL double ignition two-stroke, twin cylinder inline aero engine, 37 kW (50 hp)
• Propellers: 2-bladed wooden, 1.20 m (3 ft 11 in) diameter

Performance

• Maximum speed: 150 km/h (93 mph, 81 kn) gust or aerotow speed
• Cruise speed: 115 km/h (71 mph, 62 kn) max speed by motor = 140 km/h
• Stall speed: 65 km/h (40 mph, 35 kn)
• Never exceed speed: 205 km/h (127 mph, 111 kn)
• Range: 275 km (171 mi, 148 nmi) only if the engine is always on
• Service ceiling: 4,000 m (13,000 ft) ceiling by motor, more by sail
• g limits: +5.2/-2.6
• Maximum glide ratio: 40:1 at 115 km/h (71 mph; 62 kn)
• Rate of climb: 3.8 m/s (750 ft/min) 2.5 m/s if passenger is on
• Rate of sink: 0.65 m/s (128 ft/min) at 85 km/h (53 mph; 46 kn)
• Wing loading: 39.06 kg/m² (8.00 lb/sq ft)
• Fuel consumption: 0.074 kg/km (0.26 lb/mi)

See also

• List of gliders