new generation sailplane
for 15-meter Racing Class
SZD-56 "Diana" is the lightest, most technologically advanced in the world, high-performance sailplane of FAI 15-meter Class.
These keen on novelties in sailplane technology could notice the SZD-56-0 already at Sailplane World Championships '91, Uvalde, Texas. In those days, however, it was sooner a design study on the potentials of 15-meter Racing Class, with ambitious goal to provide a much higher level of performance than had previously been offered by any other 15-meter sailplane.
To accomplish this, over the widest range of operating conditions, the "Diana" project was oriented strictly on best performance and on widest range of wing loading - result is the lightest in the world, Racing Class competition sailplane with advanced wing of very high aspect ratio. This could only be achieved by the bold application of top technologies and materials, as well as unconventional design concept.
The outstanding brief fordesign resulted in an aircraft performances surpassing easily these of 20-meter sailplanes still in operation, unattainable until now within 15 meter wing span restraint.
SZD-56-1 is development version of glider prepared to serial production.
The interior of pilot cockpit for new sailplane version has been rearranged completely. In this modification, opinions from hitherto operators of first prototype - mostly competition pilots participating in international competition of high importance (the greater part of hitherto flown over 900 flying hours) - have already been taken into account. Unanimously emphasized were the easy and correct piloting qualities, dependable also in untypical flight conditions, while the newly introduced flaperon additionally improved the lateral controllability.
Monoplace, midwing high-performance sailplane of 15-meter (flapped) Class with "T"-tail arrangement. Owing to an unconventional design concept and fully exploited potential of employed materials, carbon and aramide fibers exclusively, the lowest - by a significant margin - weight within this sportive Class has been achieved. The unique "sparless" wing comprising 160 litre of water ballast, with 46 kg tare weight of single wing panel is to emphasize here.
A fragile sailplane silhouette can be misleading, the structure is surpassing - again by a large margin - the strength requirements of JAR-22 Utility Category which, at the ballast mass almost equal to this of a structure, result in overall load factors falling beyond limits settled for Aerobatic Category.
The right hand side mounted control stick excites curiosity. This arrangement brought the panel with board instruments nearer to pilot, thus facilitating operation of these - feature unattainable with centrally located stick, with forward deflections limited by instrument panel. Pilot's reservation as to control stick location disappear after first flight already.
Due to the wing/fuselage connection employed, unlike the other produced until now sailplanes, for user's convenience we offer a purchase of sailplane together with a trailer.
Made of solid carbon/epoxy composite. Cockpit interior elements like: floor, seat pan and back rest made of aramide/epoxy composite which, due to its crash energy dissipation capabilities, improves pilot safety, shielding at the same time against the carbon splinters.
Elastomere shock absorbed landing gear of rocking arm type, with TOST AERO 4.00 x 4 main wheel, ensures high comfort also in off-field landing.
Towing hook installed on bottom, front portion of fuselage.
In the fin leading edge an aerial for transceiver is installed, and at fin root - an integral tank for balancing water ballast of 5.8 litre capacity.
Two independent pressure systems installed in a fuselage: first one for conventional board instruments, on fuselage front portion, and a pressure head in fin leading edge, with 3 separate pressure conduits led for electronic board instruments in a cockpit.
Wide access panel located behind the wing trailing edge, on fuselage back, ensures easy access to main adjustment elements of all control systems.
Cockpit cut-out, extending far forwards onto the fuselage nose and rearwards behind the pilot's head, ensures very good visibility and comfort, when taking-up a seat.
One piece, front upwards opening canopy fastened to fuselage with 6 locks which, together with circumference sealing, ensure the high tightness.
Apart from conventional canopy slide window on left hand side, two independently controlled venting points are provided in a cockpit: front one to eliminate the possible perspex fogging, and next one on cockpit right hand side (in the area of control stick) for pilot's face blow, with both flow direction and airstream intensity control.
Automatic elevator trimming device with locking lever on a stick and position indicator on cockpit right hand side.
The correct pilot attitude ensured by the dependable, 4-point supported, on ground adjustable (fuselage lengthwise position and inclination) back rest, and in flight adjustable pedals as well as the adjustable, back rest mounted head-rest.
The 60 mm diameter instruments equipped instrument panel mounted through the column, with transceiver installed inside, to the cockpit floor.
The rectangle-tapered wing employing NN-27-13 profile, of 13% thickness, equipped with 200 mm span wingtips, on removing which the wing tank filling orifices become available. Winglet equipped wingtip available as option, when ordering the sailplane.
Wing / fuselage connection accomplished by shifting the wing over the fuselage protruding spar and locking this with a bolt parallel to wing chord. Independent assembly of each wing facilitated additionally by a low weight of single wing panel - 46 kg only.
Sparless, monocoque wing structure comprising the 4 integral water ballast tanks.
Flaperons of 17% chord ratio, over the whole wing span with hinge line at lower wing surface.
Air brake on upper wing surface only, with plate cap hanging design preventing the excessive retraction force at high airspeed.
Water ballast, 160 litre in total, contained in 4 wing tanks (2 on each wing) - front of 45 litre, and rear of 35 litre ones, with separate outflow valve for each tank. Due to control system coupling these are operated: both rear tanks, or all four simultaneously. This arrangement allows for jettison of whole water ballast within approx. 1 minute.
At fin root, an additional balancing water ballast tank of 5.8 litre capacity is provided, for C.G. correction. Controls interconnection ensures its emptying on opening outflow valve of any of wing tanks.
For contemporary sailplanes, with large amount of water in wings, the delayed recovery from unintended spin with water ballast may be critical. Due to the centrifugal force, the internal pressure at wing tips may result in a damage to a tank, or even to a wing structure.
Design of "Diana" water ballast system protects sailplane against this damage, thanks to safety valves, self-activated on exceeding the limit pressure value.
Rudder, elevator, flaperon and landing gear control systems of push rod type.
In water tank valves control a tension members are employed, while towing hook release, wheel brake and canopy emergency jettison systems are of cable type.
- Wing span 15.,00 [m]
- Length 6.88 [m]
- Height 1.35 [m]
- Wing area 8.16 [m2]
- Aspect ratio 27.5
- Stall speed 65 [km/h]
- Minimum sink speed 0.46 [m/s]
- Top speed 275 [km/h]
- Best glide ratio 48
- Empty weight 175 [kg]
- All-up weight 410 [kg]
- Payload 115 [kg]
- Water ballast 160 [kg]