A Visit to Pipistrel
Winding up my Aero coverage this week, I spent the day and a morning at Pipistrel, in Slovenia. If you donít have a map handy, Pipistrelís factory is located at†Ajdovscina, just east of †Trieste on the Italian border. Itís in a beautiful broad valley with a Mediterranean-type climate and a population that seems to be the most creative in the region. It must be; Pipistrel practically runs on imaginative aircraft development† and the factory is absolutely overtaxed with production. Itís relatively small and there are airframes abuilding in every corner of it.
I had come to take an initial demo flight in the new Panthera and also get a detailed look at the Alpha, developed from the popular Virus ultralight as a low-cost trainer. First, the Panthera. With no exceptions that are even close, the Panthera strikes me as the most beautiful civil aircraft Iíve laid eyes on. From any angle, its lines look carefully considered and proportioned and other than the top of the wings, thereís not a straight surface on the thing. It looks every bit its namesake.
But does it fly that way? It seems to. We took a brief demo flight from Ajdovscinaís 1000-meter grass runway, which is directly behind the factory. The Panthera has a 210-HP Lycoming IO-390 which propels it along at cruise speeds of about 170-ish knots on 10 gallons. Yes, thatís slower than was originally envisioned, due mainly, says Pipistrelís Tine Tomazic, to external antennas which Pipistrel hoped to bury in the fuselage. He said regulators had other ideas. Thereís also a pair of underwing steps that add to the drag load and the company is looking at making them retractable.
Along with finding the right prop, Tomazic thinks thereís another 20 knots in the airframe. Maybe. Looking at the thing from the front, itís hard to see where thereís much drag. The airplane appears to be impossibly slick. the inlets are small and I'd guess that the engine isn't overcooled. But Iím wondering if the Panthera really needs much additional speed to succeed in the market. It already meets the Pipistrel holy grail of economy. That 170-some knots it's delivering is happening at 10 gallons an hour, or 17 MPG. I havenít run the comparison numbers yet, but I think the only airplanes that deliver that kind of economy and speed are Diamondís diesel twins. More on that later.
As weíve reported, the IO-390 will be replaced by an IO-540 and the additional horsepower will give the Panthera a little more punch on the runway and in initial climb, which it could use. Tomazic said Lycoming worked intensively to get the IO-390 to deliver full-rated power on mogas, but couldnít, hence the switch to a mogas-approved IO-540. I think itís a good choice. Although mogas gets the cold shoulder in the U.S,, it's embraced by the rest of the world, even by potential owners of a $600,000-plus airplane.
Pipistrel says the Pantheraís 65 orders are from 20 different countries, many of them with high and hot conditions. The larger displacement engine will give better takeoff performance and initial climb. With the IO-390, the Panthera reminds me of a Mooney Ovation. It accelerates well enough, but it takes time to gather itself up into a fast climb once the gear is retracted. The 540 should improve that while boosting the climb rate at all altitudes. But most of the cruise speed increase, if Pipistrel finds it, will come from the correct prop and drag cleanups. Because the airframe doesnít need brute power in cruise, the 540 will be loafing, so fuel burn will be only a half gallon more per hour, say Tomazic. The additional power will bring some flexibilty.†
The Panthera has a couple of big hatches for ingress/egress of the front occupants and a Diamond-style hatch for the rear seats. Itís surprisingly wide and very comfortable, with a center stick perfectly positioned between the knees. Visibility out the side hatches is breathtaking, if slightly restricted toward the front, as the glass tapers down to meet the nose shape. Still, you never lose sight of the runway in the landing flare. An approach speed of 80 knots worked well, but given the airplaneís slow stall speed, Iíd be comfortable with five knots less.
For avionics, the test aircraft I flew had a Dynon Skyview, which it may or may not have in the production version. Pipistrel hasnít decided yet, but seems likely to offer the Garmin G3X and/or the Skyview as options. In the center pedestal, Garmin a GTN 650/750 combo handles the navcomm chores.
Regardless of where Pipistrel gets with the speed, one thing is certain about this airplane: It is pure, undiluted sex appeal of the type we havenít seen sinceÖwell, hell, Iím not sure we ever seen it. Cirrus airplanes come close, but they donít have quite the sinuous, cat-like lines of the Panthera. Iím looking forward to where this project is two years from now. Pipistrel has a good start on it and theyíre always cranking out new ideas. One of those is an intriguing hybrid drive that Iíll report on in more detail later.