A known glider and LSA builder, Slovenian company Pipistrel also offers two certified airframes with very different power plants. Steve Hitchen traveled to Pipistrel Italia to assess the Velis Electro and SW 121A Explorer.
I couldn’t say I was comfortable with this. Here I was sitting in the left seat, the safety of the journey completely my responsibility, and rain was splattering the windscreen with increasing force. Visibility was getting close to zero.
My only comfort was that I was not in an aeroplane, but driving a Mercedes Benz down a Slovenian motorway on my way to Pipistrel Italia. Regardless, the weather wasn’t instilling any confidence that I was going to get air under my backside once I got there.
My task that day in September 2024 was to test-fly Pipistrel’s two certified aircraft: the Velis Electro–the only type-certified electric aircraft in the world–and the Rotax-powered Explorer, a CS-LSA certified version of the Virus SW.
And although the fickle weather spilling off the brooding Julian Alps did dissipate closer to the Italian border, high winds still threatened to de-rail my day. It was those very winds that had me by-passing Pipistrel’s spiritual home in Ajdovscina and heading for Gorizia in Italy, the company having set up a second plant in a place where the winds permit more flying days.
But even in Gorizia, there are days when wind spoils the party, and today was looking like one of those.
We go now
Before test-flying any new aeroplane, it has always been my custom to sit down with the experts and discuss the beast I am about to fly first. A detailed briefing helps me understand what behaviours I can expect and even avoid some embarrassment.
On this day, that was a luxury we didn’t have.
Pipistrel test pilot Jǒzef Kovačič was very blunt about our scheduled flight in the Velis Electro.
“The wind has been reported at 52 knots at 6500, and 36 at 4500,” he said, eyes on the sky. “It’s only going to get worse, so if we are going, we are going now.”
Getting the low-down on both aircraft was going to have to wait, but I did have enough background on the Velis Electro to understand what it was about.
Based on the proven Pipistrel Virus/Sinus composite high-wing platform, the Velis is powered by a Emrax-built Pipistrel E811 57.6 kW electric motor turning a fixed-pitch, three-blade prop. Power comes from two batteries installed fore and aft of the cockpit, giving a practical endurance of one hour.
It has a useful load of only 172 kg, but remember that’s all people and cockpit collateral because there’s no fuel weight to come out of that and no baggage compartment.
Currently, it is the only certified all-electric aircraft in the world, and in the Pipistrel range, it replaces the Alpha Electro LSA.
As Kovačič strapped me in, he interrogated me about my Pipistrel experience. I was able to tell him I’d spent right-seat time in a Virus and had test-flown an Australia-based Alpha Electro (Australian Flying July-August 2023), which disappointed him somewhat as he thought he was about to embark me on my first flight in an electric aeroplane.
What I noticed first about Velis S5-DVF was a six-pack panel layout that was close to standard, but included no directional gyro, rather an RPM/power output gauge. The centre spots belong to a Garmin navigator and a Pipistrel-branded EPSI570 engine management system, which is one of the most crucial instruments in the aircraft, given the importance of energy management that comes with electric flight.
Also conventional is the flap lever, which is mounted Pipistrel-style at the rear of the centre console in a place where the passenger’s elbow can’t help but interfere with it.
A large variation from the Alpha I had flown before was the cooling system. The Velis is liquid-cooled using a closed system that the pilot can’t access. Batteries perform best when their temperature is within certain parameters, and Pipistrel believes liquid cooling keeps the temperatures in the best range to get the most out of the batteries.
Kovačič whipped through the pre-start checklist with a practised eye and soon had the motor energised. That brought us to the eerie situation where we’re ready to taxi, but the prop isn’t turning. That doesn’t happen until the power lever mounted on the centre console is moved forward.
Conversely, moving the power lever backwards will stop the prop, but the motor is still energised. That can be especially odd during the vital actions, which are done in absolute silence behind a motionless prop.
Gorizia (LIPG) is an all-over grass strip, so we bobbled our way out to the holding point, called the local emergency services to tell them we were departing on runway 27, checked the all-important wind sock once again and began the take-off roll.
Regardless of whether your aeroplane is powered by avgas, jet fuel or electron flow, the next bit is standard pilot stuff. Apply full power, maintain the centreline (even if it’s imaginary), wait for rotation speed and fly the aircraft off. None of that was different in the Velis Electro, except the engine management system was telling us our endurance was 15 minutes.
That’s barely enough for a circuit, but as Kovačič levelled out into the cruise and brought the power back, that reading settled at a far less stressful 45 minutes, illustrating how sensitive the endurance is to power setting. Leaving 15 minutes of power in our pocket, that meant 30 minutes of playtime.
After settling into a cruise of 90 KTAS at 3000 feet, Kovačič turned the aircraft over to me.
I have control
To the east is Slovenia (don’t go there), to the south is Trieste/Ronchi International Airport (or there) and to the west is controlled airspace (or there). Any attempt to venture north drew an angry response from the wind pouring off the Julian Alps. Staying in G airspace also means remaining below 5000 feet AMSL. We were going to be flying inside a phone box!
Kovačič pointed out the best way was to stay overhead the airfield, which wasn’t a safety risk because Pipistrel is the only operator on the field and they’d cancelled all production flying for the day. That meant I had the airspace to myself.
After swinging through some turns of varying angles of bank, I quickly realised that the legendary Pipistrel handling had been grandfathered over to the Velis Electro. Add to that a very crisp response to power inputs and you have an excellent trainer laden to the gunnels with fun factor.
Control inputs are minimal, almost helicopter-like, when it comes to the force required to illicit response from the ailerons and elevator. That’s what you get with long, slender wings that hark back to Pipistrel’s origin building gliders.
Throughout the flight, Kovačič and I kept an eye on the EPSI570 and its battery condition and available flight time displays. Unlike piston-engined trainers, you can’t bury yourselves in the sequences and give scant regard to the fuel situation.
But that didn’t stop us using some of the available energy climbing up to 3500 feet and setting up S5-DVF for stalling.
The Velis Electro is what I would describe as a brilliant staller: gentle, no wing-drop and plenty of warning. There was a lot going on in the cockpit as we approached the critical angle; the aeroplane is fitted with both a stick shaker and a rattler, providing both haptic and auditory warnings.
When the stall did come, I didn’t recognise it. The only indication I had was the vario telling me I was going down at 950 fpm. The ailerons remained effective throughout the stall, giving the misleading impression that I was still flying.
Jumping seats
Battery condition wasn’t the only restriction we had on flight time; swirling winds were a constant reminder of the change to come and I still had to get my backside in the Explorer.
Landing an electric aircraft is not a lot different from conventional types. There are speeds to be hit, approach procedures, checklists and so forth. The only real difference is the instantaneous response to the power lever. Want power now? Move the lever and you get it immediately. The same works in reverse.
Kovačič demonstrated that expertly as he greased DVF onto runway 09; the wind was such that we were able to use the reciprocal runway to the take-off.
Much later, I was able to quiz Pipistrel President and Managing Director Gabriel Massey about the capabilities of the Velis Electro, and his answer left me in no doubt that they understand the limitations caused by battery capacity.
“Endurance will continue to be a problem for the time being,” he told me over a platter of pastries. “In the US a lot of schools don’t have training areas that are immediately beside the airport. We have 30 Velis Electros in France that have been able to demonstrate regular 45-minute lessons, which is 60-70% of doing a PPL.
“The endurance is something that will continue to improve with battery technology. Aviation has long cycles when it comes to improving aircraft; a major change takes a long time. For example, we have to select a cell that goes into the certification program, and by the time you’re even starting the program, that cell can be three generations old!
“But we have to stick with it because that’s what we started certification with.”
Massey is very aware that the Velis Electro, for all its efficiencies, doesn’t represent the end game when it comes to certified electric aeroplanes, but rather is the next step towards emissions-free practical flight, a journey that started with the Alpha Electro LSA.
“The Velis Electro represents the natural progression of the product,” he explained. “We’ve put a lot more into the design, the build, the battery system and the certification process. The Velis is the next-generation product that continues on from the Alpha.
“The Velis itself may not have an significant impact on global emissions reduction, but in order to pave the way for new technology on larger products, it is important to get adoption started. Small GA is an enabler for larger change.”
Alongside the Velis Electro in Pipistrel’s certified stable is the SW 121A Explorer. The demo aircraft was waiting for me, and the wary eyes of pilot Martin Vadnu told me he was as jumpy about the advancing weather as Kovačič had been.
Consequently, the process of strapping me in and locking the doors felt somewhat like a Formula One pit stop. Having literally leapt out of one Pipistrel and straight into another generated a degree of cockpit shock given that one aircraft was electric and the other Rotax powered. Chalk and cheese.
The Explorer, however, was not that different from the SW 100 Virus as far as I could see, which of course led me to propose the cheeky question. What exactly is the difference?
It was an easy question for Vadnu to field as we taxied out to the runway: the Virus is a light sport aircraft built to US light sport rules, where as the Explorer is an EASA CS-LSA certified aircraft with IFR training capability, G3X avionics and ballistic recovery parachute as standard, and is approved for intentional spinning.
Our demo machine, S5-DIB, had a neat Garmin panel that included two G3X screen–one set up as a PFD and the other as an EMS–a Garmin autopilot, GNX 375 navigator, comms and transponder.
On the other side of the firewall, the Explorer boasts a certified Rotax 912 S3 engine spinning a two-blade MT constant speed prop, also EASA certified.
Performance-wise, there is not a lot to split the Virus and the Explorer, but the Virus has a useful load in the range of 311 kg (they vary with options and MTOWs), whereas the certified Explorer is pinned at 229 kg. That’s still enough for two 77 kg and full fuel, but you’ll have to offload fuel to get a decent weight of bags in the back.
That wasn’t going to be a problem for Vadnu and me; we had plenty in reserve and weren’t going to be wandering far from the circuit.
Exploring the sky
It doesn’t matter which variant of this airframe you’re dealing with; they all love to fly. With a spreading 10.7 m wingspan, flowing composite fuselage and T-tail elevator, the Explorer boasts the same glider heritage as the Velis Electro.
That became evident as DIB used Gorizia’s grass runway sparingly as Vadnu set up a 78-KIAS climb using 5500 RPM, returning a climb rate of nearly 1000 fpm. Our playground was at 4000 feet, and at that rate we wouldn’t be long getting there.
Established once again in our phone-box training area, Vadnu handed me the stick and set-up a vigil to ensure I didn’t stray across the Slovenian border or into the path of airliners or angry controllers.
I stabilised the Explorer in a cruise using 5000 RPM and 23” MAP. The Garmin panel told me we were making a good 124 KTAS, paying a price of 18 LPH to do it. That is one of the best bangs-for-buck that you’ll get in an aircraft of this class.
And that brought into focus one of the negatives of this airframe: it hits bumps very hard at that speed. The Julian Alps were delivering us some atmospheric rubble at that altitude, shoved at us by a stiffening 36-knot easterly. The trick would have been to back off the power and accept a lesser TAS, but I wanted to see how well DIB cruised.
But straight-and-level can get beige on you very quickly, so I took the occasion of needing to steer back into Italy to try some steep turns.
The only thing worth remarking on is that the rudder is a bit heavy, but that’s balanced by the fact that very little movement is needed to centre the ball again. I found myself very comfortable with this because it helped resist over-controlling with the feet.
The elevator load was nothing to remark on, and I finished the sequence with a self-satisfied smirk on my face ... which lasted until Vadnu pointed out I was going the wrong way and needed to drop a 180 or penetrate Slovenian airspace.
At that moment the G3X began to give us a wind indication that we didn’t like. It was getting stronger, so I handed DIB back to Vadnu and called for a return to Gorizia with a short-field landing.
Of course he aced it ... why would he not? Crossing the fence at 60 KIAS with flaps full, Vadnu brought us to a stop on the grass runway in about 60-70 metres tops. I need to qualify his performance by pointing out the 16-knot headwind that gave us a 47-knot GS on final.
We chanced our arm with one more circuit, this time I deprived him of his flaps (they’re mechanical and have no real chance of failing). Vadnu built another five knots onto the ASI and side-slipped DIB all the way down final to a landing that was remarkably like his short field effort.
After shut-down, I shook hands with Vadnu for a demo flight well done in sketchy conditions and remarked how well the Explorer handled if you were disciplined enough to stick the numbers.
What Can I Learn?
Watching the billowing windsock from the safety of the Pipistrel board room, I started on a number of questions I had prepared to throw at Massey. Question #1 was why, when you’re already a successful light-sport manufacturer, would Pipistrel go down the certification path with the Explorer?
“We still have the Virus and Sinus in the ultralight and LSA categories,” he responded. “It is very clear, though, that if we want to go into the pilot training market at 600 kg, the EASA CS-LSA category was the right thing to do. We feel good about that, because there are lots of flight schools out there that require type-certified aircraft.
“Going with the basis of the Virus SW–it does have a different cockpit layout to meet the certification requirements–was really the market. It’s actually new for flight schools to go from a Part 23 aircraft to anything else; LSA in the USA, Australia, Brazil or even CS-LSA in Europe, it’s very different for schools, and going into a type-certified LSA was more manageable step to adopt.
“We see the Explorer as an all-round trainer, although some owners do use them as personal aircraft. I think there is an amazing opportunity in Australia because it has the endurance and feels like a great touring aeroplane for the long distances in Australia.”
One setback, however, is that certification fixes the Explorer configuration the way it is, whereas the Virus can be taken in multiple different directions: taildragger, different types of the Rotax iS engine, three-blade prop and so forth. The Virus has the configurability, whereas the Explorer doesn’t.
What the Explorer does do, is set-up Pipistrel to take advantage of the Modernisation of Special Airworthiness Category (MOSAIC) rules currently being developed in the USA, which will unshackle manufacturers from the current restrictive LSA standards.
“We see the Explorer as entering the US market once the MOSAIC rules are published,” Massey pointed out. “Right now, the Explorer doesn’t fit the FAA’s LSA definition, but it will fit right in with the MOSAIC definition. That’s a big opportunity for the products.
“We’re in a position to take advantage today of product that doesn’t have great market penetration in the USA because it doesn’t fit the LSA market and it’s not a Part 23 aircraft.”
The upshot
I came away with the impression that Pipistrel and parent company Textron both have a clear vision for the future of GA and are producing the products to match. Certification brings an amount of certainty, which is something most GA operators would like a bit more of.
I would have liked more time with both the Explorer and the Velis Electro, but as I drove back along the motorway, watching trucks struggle with wind on the high bridges near Adjovscina made me glad I hadn’t pushed the point. 