I just got home from visiting a Pipistrel Taurus Electro owner in Texas to go for a demo ride in his glider. I met him in July of last year at the Pipistrel booth in Oshkosh. They had his brand new airplane on display in their booth with him taking ownership at the end of the show. We've been talking on the phone recently about gliders in general and the Taurus Electro as I work on earning my glider rating. His is only the 3rd Taurus Electro located in the US. Over the last year, he's become familiar with the new airplane and let the previous glider collect dust in the hangar, so it's up for sale.
For those not totally familiar with the glider (I've mentioned it previously here), the Taurus Electro is a self-launching battery-powered glider. Since it's designed to be a soaring glider, with a relatively high-performance 41:1 glide ratio, it has a relatively small battery, roughly 10 kWh. This is enough energy to takeoff and climb to 8,000'. The normal profile is that you takeoff and climb to about 2,000' and then shutdown and stow the motor while you search for thermals and have a little extra energy saved in the battery for a 2nd takeoff later in the day or a "save" to keep from "landing out" (somewhere other than an airport) and avoid the danger of an off-field landing and the hassle of taking apart the glider and hauling it back to an airport.
The primary goal of this trip was to confirm that the Taurus Electro lives up to the promises of the marketing literature. The noise with the motor running was fairly low, but we still used headphones. Obviously, there was no engine exhaust noise, but there there was a little vibration/noise through the airframe and noise from the prop. The noise was low enough, that many would consider the headphones optional. While GoPro cameras sometimes have really funky audio, the YouTube videos are pretty representative of the cabin noise. All the preflight checks of the drive system are handled by the on-board computer, so no need for an engine runup. Takeoff roll was brisk and even with us just a little shy of the max gross weight, we were soon climbing at over 500 fpm. At 200' altitude, the power was reduced from takeoff power, then at about 500' altitude, we hooked a thermal, so he started circling over the airport and lowered the motor power even further. It only takes about 3 kW of motor power to maintain level flight without thermals. It wasn't the greatest day for soaring, so we took 15 minutes milling around at relatively low power looking for lift before we got up to 2000'. At this point, we shutdown the motor. The twist knob throttle goes to 0, the automatic brake stops the prop vertically and then you flip the switch to stow the motor after which, the drive electronics can be fully shutdown. 15 seconds for the whole process. We consumed 33% of the battery pack for our leisurely takeoff climb.
We proceeded to fly around the area for a little over 2 hours. Eventually climbing to over 5,000' agl (the base of the broken cloud layer) on the thermals that were available. I haven't talked about cross flying with my glider instructor yet, just working on earning the initial rating right now, so he gave a little guidance on general techniques. I've seen a bunch of videos on the topic of soaring, but it was great to get some guidance from someone that's been flying gliders for over 50 years. The idea of cross-country flying in a glider makes a little more sense now. At one point, we were 4,000' up and soaring/circling in a thermal with 5 vultures. All of us up together, just passing time enjoying the joy of flight. In a powered airplane, birds dive away from you, but in a glider, they just keep milling about their day. As we descended back down, we redeployed to motor just to prove that this works. Slow to 50 kts, activate the electronics, deploy the motor, turn up the throttle. Super easy to deploy/retract the motor in flight. Compared to the two-stroke engines many motor gliders had previously used, the electric drive is great because there is no warm-up/cool-down procedure as the motor is extended/retracted.
This flight is going to be an expensive one. It just confirmed what I had hoped would be the case with this glider. I've been wanting this glider for a few years and now, it's pretty much inevitable that I'll buy one. The only real question now is the schedule on when it will happen. Kind of depends upon the what the actual purchase price works out to be. Their prices at airshows are significantly different than the retail prices poster on the web site. At least the US Dollar has been getting stronger compared to the Euro, to that's been helping drive the price down over the last several years.
For the current battery technology (energy density), the glider seems like one of the only airframes that electric power is really viable for. The glider doesn't need a lot of energy in the batteries because once you're up in the air a couple thousand feet, you can find thermals and extract energy out of the air itself. The single-person capabilities of the Taurus Electro (two main wheels allow you to taxi around the airport without a wing walker; no need to a tow-plane pilot or winch operator) and the super-low operating costs (our 2.2 hour flight cost about 15 cents for electricity) make this a great aircraft.
