PZL Bielsko SZD-50
| PZL Bielsko SZD-50 Puchacz | |
|---|---|
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| Type: | School / performance glider |
| Design country: | |
| Manufacturer: | |
| First flight: |
December 21, 1976 |
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The PZL Bielsko SZD-50 Puchacz (German: Uhu ) is a two-seater training and performance glider from the Polish manufacturer PZL Bielsko (now Allstar PZL Glider). The gliding index is 84.
history
The development of the Puchacz began in the mid-1970s with the aim of building a modern, two-seater school glider with good handling properties in the mid-price range. It was based on a prototype called SZD-50-1 "Dromader". This had its maiden flight on December 21, 1976 with Adam Zientek. The prototype had, similar to the SZD-9 Bocian , a normal tail unit, which led to considerable problems. Even experienced pilots did not succeed in exiting the aircraft earlier than after three spins (the Bocian was stable again after half a revolution). According to Polish pilots at the manufacturer, a prototype was lost in this way. The reason for the unacceptable flight behavior during a spin was that the low normal elevator unit was completely in the wake vortex of the wings during the spin and was almost ineffective. The tail unit was then redesigned. As a cross stabilizer with a raised horizontal stabilizer, the aircraft could be brought out of the tailspot without any problems, even if not as well as the very good-natured Bocian .
The actual prototype of the Puchacz only flew a year after the "Dromader". Production began in 1979. The Puchacz was then often used for training in several countries, including Germany . The GDR deployed 62 Puchacz in the GST from 1983 . The factory stopped production in 2014. Instead, the new two-seater SZD-54 Perkoz will be built.
construction
The middle decker is made in GRP half-shell construction, only the rudder and elevator are covered with fabric. The trapezoidal wings have large spoilers that can be extended downwards and upwards, which enable an extremely steep landing approach compared to other gliders. Before the aircraft is intercepted on landing, the spoilers must be partially retracted again, since otherwise the aircraft will sag down and cannot be intercepted. The cross tail is set at half height, which also ensures sufficient ground clearance when landing outside in tall grass or grain fields. The landing gear consists of a brakable, rubber-sprung main wheel, a small nose wheel and a grinding spur at the stern. All copies delivered to the GDR have an efficient disc brake built into the main landing gear, which is triggered by the pilot using a cable mechanism on the left side of the cockpit. The student pilot sits in front, the instructor in the back. A second dashboard for the flight instructor can be ordered from the manufacturer. In an emergency, the one-piece cockpit glazing can be triggered by the pilot as well as the flight instructor or fellow flyer, with the person sitting in the rear relaying the triggering of the emergency release of the canopy to the front via Bowden cables . The aircraft has an "on-board toilet" for liquids integrated in both seats. All rudder connections (ailerons, spoilers, elevator) are automatically connected when upgrading. The price for an airplane was 120,000 GDR marks.
use
The Puchacz is suitable for all types of glider training including simple aerobatics . This aircraft can also be used for training in equipment flight and high-performance flight. The following aerobatic maneuvers may be flown with the Puchacz: looping, turn, corner curve, steep circle, spinning and downswing. With little effort (installation of a 5-point belt, g-knife, etc.) the Puchacz can be converted to the “Acro” category, which also enables inverted flight and rolling. The maximum speed of only 215 km / h is a limiting factor in aerobatics.
As a two-seater, the Puchacz is a good-natured, manoeuvrable glider, which is very suitable for training. In particular, the spin can - in contrast to many other two-seaters - be demonstrated well.
The Puchacz climbs very well during thermal flight, both thanks to its low weight and good maneuverability. The glide ratio is moderate for a GRP aircraft.
Technical specifications
| Parameter | Data |
|---|---|
| Manufacturer | PZL Bielsko |
| constructor | Adam Meus |
| span | 16.67 m |
| length | 8.38 m |
| Wing area | 18.16 m² |
| Wing extension | 15.3 |
| Glide ratio | 30 at 85 km / h |
| slightest sinking | 0.7 m / s at 75 km / h |
| Empty weight | 365 kg |
| payload | Max. 205 kg |
| Takeoff weight | Max. 570 kg |
| Passengers | 1 |
| crew | 1 or 2 |
| Top speed | 215 km / h |
| Maneuver speed | 160 km / h |
| Stall speed | 60 km / h |
| Max. Load multiple | + 5.30 / −2.65 |
Web links
- Manufacturer's website (Polish, German, English and French)
- Type certificate of the SZD-50-3 "Puchacz" - EASA-TCDS-A.312 (PDF; 88 kB)
- RC-Modeling & Polish Sailplanes - Extensive information about Polish gliders
- Type description at Geelong Gliding Club (English)
- Film recordings of three flights with an outboard camera