The Leading Edge: Finding LSA ‘Unobtanium’

By Steven Barbour, EAA 596000

We all want the impossible in our aircraft, right?

There she was, a sleek, composite, tandem-seat, retractable-gear aircraft, complete with a side stick and modern avionics — an exciting discovery during my 2022 visit to Oshkosh. Trey Murdough, the distributor, was kind enough to let me hop in and make airplane noises while entertaining an onslaught of questions. This aircraft resonated with my fighter lineage of years past. I loved it. My first question was: What is it?

What I was sitting in that day was the Stream, a product of TL Sport Aircraft in the Czech Republic. During conversation it was referred to as a light-sport aircraft (LSA), which initiated an internal sigh of letdown knowing the performance limitations on LSAs in the United States. When clarified as a European LSA (technically an ultralight, or UL category, see side note) that enjoys a much wider design and performance envelope, I quickly regained interest. Naturally, the second thought is: How can I get one? The answer to this question is what put me on the path to the Czech Republic for my next build.

The simple fact that these complex, high-performance aircraft do not qualify as LSA in the U.S. left me two options. One option is importing the fully built aircraft and getting an experimental exhibition airworthiness certificate and complying with the FAA rules and regs that accompany that program. There are a lot of opinions for and against choosing that option, but for me it seemed like a cloud that would forever be following me around.

Another option is utilizing a builder-assist program (if offered) by the manufacturer and getting an experimental amateur-built airworthiness certificate, commonly known as E-AB. This involves going to the manufacturer and fulfilling the 51% portion of the build in country. I chose the latter, having experience with my previous experimental RV-6A.

It is worth mentioning that at that time in 2022, MOSAIC was still years away. We are promised light at the end of the tunnel for some time in 2025. If implemented as currently proposed, most of these high-performance European ultralights will still not qualify as an LSA in the U.S. MOSIAC and/or the manufacturers will have to address a gap created by MOSAIC’s clean stall speed requirement of 54 knots or less. This is one area receiving attention in the MOSAIC comment period, in particular from EAA. Once resolved, these aircraft should be eligible for purchase stateside as an LSA. The final version of MOSAIC will determine how this scenario plays out.

Like most things in aviation, these birds also bring a hefty price, which drives a prudent person to research the market and ask tough questions. Looking beyond U.S. borders, I discovered a buffet of high-performance “ultralights” to consider, both tandem and side-by side. There is something for everybody. With such a selection to choose from, my first criteria was a company with an established U.S. presence, a builder-assist program, and stateside demo flights. The field narrowed quickly. I demoed three aircraft: the Stream (Czech Republic), the Tarragon (Latvia, also tandem) and the JMB VL3 (Czech Republic side-by-side). All three are beautiful aircraft, and they squeeze impressive performance from their respective Rotax powerplants, but not quite the numbers I was desiring. I wanted it all — 1500-plus fpm climb, turbocharged, 165-plus TAS cruise, retractable gear, constant speed prop, IFR, auto pilot, a recovery chute, and all that on 8 gph of auto fuel. You get the idea! Most importantly, it had to look good sitting in my hangar at the house.

After the demo flights, I came to the realization that my expectations exceeded what was currently available. Fortunately, about this time the 160-hp Rotax 916 was debuting and DUC’s four-blade Tiger prop was making the scene. I decided to stay in the game. Little did I know that within a year these new developments would push the performance of these airframes right up the scale.

Since then, TL had equipped their Sparker aircraft (side-by-side version of the Stream, sharing the same wing) with a 144-hp Rotax 915iS and the DUC Tiger prop (the 916 is now standard). Tarragon’s stateside bird I demoed had a 915iS installed, and they are currently on track for delivery in 2025 of their high-performance variant with various refinements. JMB had installed the 160-hp Rotax 916 in their already speedy VL3 aircraft. It was time to head to the Czech Republic to witness these new upgrades and see if they truly translated into the performance I was hoping for. They did!

I flew the Stream, the Sparker, and the VL3, and I toured both the TL and JMB manufacturing facilities. I did not make it to Latvia this trip. My desired performance was delivered by both side-by-side aircraft as hoped. The tandem Stream aircraft at the factory was configured the same as the one I flew stateside with the same impressive performance for the 100-hp engine, but not competing in the same league as the higher-powered side-by-sides.

What stood out to me from each is as follows: the Sparker is very refined and comfortable, the VL3 was the best performing but was a bit snug for me personally, and the Tarragon excels in handling characteristics and curb appeal. I base this off my 41 years of flying including fighters (hence my tandem seat desire), corporate, major airline, and general aviation throughout. Again, there is something for everybody depending on your mission and personal preference.

Back stateside, it was time for a go/no-go decision. My tandem options were accepting the 100-hp performance of the Stream or waiting until sometime in 2025 or later for delivery of a Tarragon. I could exchange tandem seating for the performance of the side-by-side Sparker or VL3. Or just abandon the process all together.

Shortly after returning, Trey called with some news. TL Sport Aircraft would be equipping the Stream with an 180-hp Edge Performance 917 engine and the Tiger prop. Would I consider it? Sounds perfect to me, but how long for R&D and to get an engine and a prop? Do I really want to be the launch customer for this configuration? Can they make it work? Normally I would have balked at this proposition, but what I had observed during the TL factory visit allowed me to make a very confident decision of YES.

Production would start immediately. I was amazed at the short lead times TL reported in getting the big pieces: engine, prop, chute, avionics, etc. The builder assist portion was scheduled for five months later with delivery to the U.S. just a couple months after that. Looks like my dream build may come to fruition.

That sleek demo bird at Oshkosh led to the discovery of a whole new up-and-coming breed of high-performance aircraft emerging in Europe spurred on by maturing technologies. I believe this segment of the market will be well received in the U.S., and a surge in demand will follow the implementation of MOSAIC. I would like to believe I got in on the leading edge of this wave, but for right now, it is time to return to TL Sport Aircraft in the Czech Republic for the builder-assist portion. Stay tuned to see how the build goes.

Side Note:

When the term ultralight is mentioned in the U.S. you immediately think FAR Part 103 with tube and Dacron and a max speed of 55 knots. An ultralight in Europe is basically an LSA (European and U.S. LSAs are, for the most part, identical programs) with all the restrictions lifted except for 1,320-pound. max takeoff weight and a 45-knot VSO stall speed, hence the complex portion of these aircraft. These are far removed from U.S. ultralights! Hence, the manufacturer is TL Ultralights in the Czech Republic, and the distributor is TL Sport Aircraft in the U.S.

Post Comments

comments