Since the time of my last visit to the SZD AllStar Glider factory in Bielsko-Biała, Poland in August 2011 the company has been very busy with the certification process of the new 20m version of the Perkoz. As of September 29th, 2012 all of the flight-testing requirements under CS-22 regulations have been completed and the new airship will enter the market with similar restrictions to those of the 17.5m version.
Full view of the SZD 54-2 Perkoz
According to information from the test pilots, the new 20m Perkoz performs very well and shows no particular vices. In a previous article by this author, several valuable features of the Perkoz were noted, such as, cockpit ergonomics, stability and maneuverability, ease of ground steering and very light control forces in flight. Additionally, control surface flutter, when induced by the pilot, showed very rapid dissipation of vibration. This outcome suggests that this new glider is virtually free of flutter characteristics.
View of the glassy 20 meter wing
Extremely positive finding was performance of the aircraft under full spoiler deployment. Current CS-22 regulations require that an aircraft maintain a glide path of 45 degree minimum down angle from the horizontal line of flight at Vne. The Perkoz SZD 52-2 maintains a 50 degree down angle from horizontal at Vne. This is a remarkable achievement in my opinion.
View of the spoiler at Vne during testing flights as recorded by the flight recorder
Another positive for the new Perkoz are the flight characteristics regarding spiral and spin entry. The glider does not show any tendencies for unintentional entering of a spiral or spin. However, if a spin is entered, and even though it is relatively steep, the recovery is not difficult. Rotation can be stopped immediately, but keeping in mind the glider is losing altitude, exit from the spiral/spin needs to be accomplished rather quickly. As we shall show below, this ship is rather slippery but even so, handles very well at the lower airspeeds associated with these conditions.
SZD 54-2 Perkoz in flight with the Tatra Mountains in the background
Initial technical data of the SZD 54-2 as published on the Allstar PZL Glider factory web site (http://szd.com.pl/) indicated an anticipated L/D of the 20m version to be a modest 42. Since the testing in determining the true L/D is still in progress, the company is not presently releasing the current L/D data. I have gathered, however, that the true L/D has exceeded the initial expectations. I am sure that following company test pilot confirmation of the actual L/D numbers, Allstar PZL Glider will publish them shortly thereafter. In the meantime, I understand through the grapevine that the number is more likely to be in the area of 45:1, but do not quote me on that just yet. I would be much more comfortable to await the official company report.
20 meters extension panels
Yet another significant point to make about the development of the SZD 54-2 is its adaptability to a wide range of pilots and piloting skills. The other production two seat sailplanes available in the marketplace, because of their size, weight and limited configuration variables, require very specific piloting skill levels and handling. The Perkoz, in contrast, is capable of multiple configurations thus allowing pilots of varying abilities and experience to fly the same ship safely.
SZD 54-2 Perkoz on final approach
As a final note, in October of 2012, AllStar took the 20m Perkoz to the Mountain Flying School "Żar" attracting a large crowd in the process and allowing many pilots to try out and fly this new plane.
The above two pictures are showing October activities at the Mountain Glider Flight School "Żar"
Two of those pilots who flew this new 20m, were Sebastian Kawa and his father, Tomasz. I have exchanged several emails with both and both too had similar things to say the airplane; that it is very good, easy to handle and well behaved. One mentioned, for example that he was able to take off without the aid of a wing runner because the wings came up very quickly and within a few seconds he was in full control of the airplane. I was also told that when he deflected the control stick fully to either side, the stick returned to center and the plane only "waved" slightly in the direction of the input. Another factor mentioned in the discussions was that even though this 20m ship could fly well in very weak conditions, by simply removing the extensions and putting the plane into the 17.5m configuration, one could convert the plane almost instantly into a nearly full aerobatic machine.
In the aft cockpit is Mr. Tomasz Kawa
In light of all of these favorable developments, I remain quite hopeful that this new sailplane will find its way into many soaring clubs around the world and maybe even into the hands of several private owners who can utilize the flexibility of the Perkoz to not only master the art of cross country soaring, but that of glider aerobatics as well.
Pasco, Washington State
All pictures are courtesy of PZL Allstar Glider, Sebastian Kawa, Tomasz Kawa and Michał Ombach.