By Walt Burkett Jr.
Last week, I visited the Sling factory in Johannesburg, South Africa, and took an introductory Sling TSi flight. For most, this 15-hour flight from Atlanta would be too far away to visit, but for me, it was no problem as I was flying the Delta A350 there as one of my scheduled monthly routes. The next morning, after some rest, I took a 30-minute Uber to Tedderfield Air Park (FATA S26°21’06” E27°58’09”). On one side of the field is the Sling factory with its multiple hangars; the other is Air Park homes with attached hangars.
When I arrived, I followed the sign to the reception building and went in. I was immediately met by Jonathan Shaw, one of Slings’ sales Executives. We talked briefly, and then Jonathan said, “Let’s go flying.”
Before I talk about the actual flight, some of you may be wondering what a Sling TSi is and why I chose to build one. First, I will discuss some history. Sling Aircraft, previously known as TAF or The Aircraft Factory, is a light aircraft manufacturing and maintenance business located in Johannesburg, South Africa. Their first aircraft was a 2-seat light aircraft, the Sling 2, which flew in 2008. From there, they designed and developed the Sling LSA, Sling Taildragger, Sling 4, and in 2018, the Sling TSi, and finally, in 2020, the Sling TSi High Wing.
The use of the Rotax engine makes Sling different and unique from most experimental aircraft manufacturers, at least in the US. I say in the US because Rotax engines are actually used in more light aircraft worldwide than any other manufacturer. Rotax, or, more appropriately, BRP-Rotax, is an Austrian company founded in 1920, and their engines are in not only aircraft but also Snowmobiles, motorcycles, personal watercraft, off-road vehicles, as well as karts. (I currently have two Rotax engines in my Scarab HOI Wake boat. 2-250HP supercharged Rotax engines) The aircraft application is a lightweight, high RPM engine, over 5,000, with an attached reduction gearbox that brings the propeller RPM down to around 2400 RPM. It’s designed to accept mogas with 10% Ethanol content but can also accept 100LL. The 916is engine, which I have selected for my build, is a dual lane, electronic ignition, liquid-cooled, turbocharged/intercooled engine that produces 160HP for the first 5 minutes after takeoff and then automatically reduces to approximately 140HP and weighs in at less than 190Lbs! The factory has attached a 2000 TBO. (Sling produces both an aircraft kit and a fully built aircraft for ROW, rest of the world, but only experimental kits for the US market. (US litigation as well as certification costs)
The Sling TSi performance specs are impressive. The aircraft has an empty weight of around 1,100 Lbs. with a max takeoff weight of 2,100. The useful load is around 1,000 Lbs. It cruises around 155 KTAS at 9500′ with a burn of approximately 7.5 GPH. The climb rate after takeoff is around 1,100 FPM, slowly decreasing as you climb. The turbo is a normalizer keeps an approximate sea level boost up to 15,000 feet with a service ceiling of FL230. (Although test flights have reached FL280!) Sling advertises an operating cost of around $60 per flight hour, so the aircraft is impressive in all aspects.
So why did I pick a Sling TSi to build?
Looks, performance, reliability, cost and uniqueness.
The Sling TSi is a very good-looking airplane, and as I have previously mentioned, it performs extremely well. The engine is extremely reliable, and there are literally thousands of them worldwide. What about the cost?
When I ordered the Sling TSi kit, the prices as of May 2023 were as follows.
Empennage (Tail) Kit: $5,160
Wing Kit: $20,260
Fuselage Kit: $21,240
Undercarriage Kit: $13,260
Canopy and finishing kit: $16,950
There is a small discount if you order all the kits simultaneously, which is about -$1500.
There are also numerous TSi kit options, including a BRS parachute, LED lighting kit, upgraded Beringer brakes, and many more. My airplane should come in around $400K, including my builder assist costs and pretty much every option. The cost of the Rotax 916is engine with the firewall forward kit and 3-bladed MT prop is $77,500. The single lever RS system is an additional $6,000. The BRS parachute comes in at $19,995. The leather upholstery and carpet cost $6995, and the Garmin panel comes from Midwest Panel. (No total there either since I may be changing a few things. It will, however, be loaded with 2-Garmin 3X displays, and I am looking at a Garmin 750i navigator.) Updated pricing and order information can be received from the US importer, The Airplane Factory in Torrance, California. The point of contact is Edward Hefter, sales manager.
Another huge savings in cost is the fact that the Rotax engine is designed for Mogas. In fact, it prefers it. Addison, the nearest airport to me sells 100LL for almost $8 per gallon! Filling my 52-gallon tank would cost $416.00 vs $200.20 using Premium 93 Mogas located just down the street.
That brings us to uniqueness. There are over 200 Sling TSi’s in the US market, and more are ordered each week. Still, compared to many other experimentals in the US, Sling maintains a very, very small percentage. That uniqueness appeals to me.
“Let’s go flying”
We started our walk over to the Sling TSi, and it was fully ready, fueled, and pointed in the taxi direction we needed to go. (We had to traverse grass before getting to the runway) Jonathan was talking about the airplane, performance
and capabilities along the way and didn’t miss a beat as he started the pre-flight. I followed along, but it’s the same for every small aircraft I have flown. The TSi has relatively high gullwing doors/windows and getting inside the cockpit is a challenge, especially if you don’t want to step on the seat. Having a towel on the seat so as not to step on it would make entry easier. As we turned the electronics switches on, the G3X display came to life, and we verified the battery, fuel load, fuel pumps, and other prestart items and then fired it up. There was no hesitation. The 916is immediately came to life and we checked the oil pressure, ran a taxi checklist and started our roll to the runway. Another unique thing about the TSi is its direct connection with a rudder/nose wheel. (This makes for very small impressive turning radius.) Interestingly, Sling decided to utilize a hand braking system with a brake lever just to the right of the throttle. It seems a little odd when you are used to toe brakes, but adapting to it is quick and makes simple sense. (Fewer parts, more accessible access to one master brake cylinder) There is a toe brake option if you want one, however.
The engine is at home at around 2,000 RPM, so that’s where we kept it. When we got to the hold short, we started our before takeoff check, which included increasing the RPM to 4,000 and checking the two electronic ignitions, called lanes, specifically Lane A and Lane B. The check consists of turning a Lane switch off, checking the minimal RPM drop, if any, turning it back on, and waiting for the red lane light to extinguish. That’s done for both lanes, and then a quick check of the aux boost pump, some other quick checks to include pulling the prop lever back, and then a call for takeoff. (This aircraft had a manual prop lever that was located between the throttle and handbrake. My aircraft will come with an RS system, single lever, whereby the prop pitch will be adjusted automatically. Essentially, I will just have a throttle.) Although we did this in the runup area, that was so Jonathan could take his time to explain everything to me. This could quickly and easily be done on the taxi out, passing all those in the runup area and heading straight to the hold short for takeoff. Once we took the runway and advanced the power to the firewall, the aircraft accelerated very quickly. Although the field elevation was 5,200 feet and the temperature 80F, the turbo normalizer increased boost to create a sea level condition for the engine, and the performance was attention-getting. Rotation was 55 KIAS, and climb out was at 74 KIAS. I stopped my initial pitch at around 12 degrees but quickly realized I was going to need higher than that to stop the airspeed at 74 KIAS. The pitch ended up being around 17 degrees nose up to maintain that 74 KIAS, and I held that pitch until we reached 3,000 AGL, as Jonathan instructed. I never looked at the VSI, but I’m sure it was north of the Sling advertised 1,100 FPM.
At approximately 8,000 MSL/3,000AGL, I leveled off and quickly looked for other traffic. I flew some steep turns as well as clean and dirty stalls. The aircraft was very light on the controls, and by simply adding full power in the stalls, it would quickly pull itself out of the stall without having to degrease the AOA. I was surprised at just how benign and docile the stalls were, and considering the AOA alert tones as well as visual AOA indexer on the G3X, one would have to be sleeping to not preemptively avoid the stall or quickly and easily recover from one either with power, or bunting the nose without it. The visibility out of the aircraft was excellent, especially looking over the nose below the horizon. I was very impressed by this TSi in all aspects! (Just as a point of reference, I am not a small airplane expert. I have about 250 hours in small aircraft. My background is in the Navy F-14A Fighters, with over 2,000 hours, and Airliners from the DC-9 to the A350, with over 20,000 hours there.) After the 40-minute flight, since the winds were gusty and the runway very narrow, at least narrow compared to what I was used to, I asked Jonathan to do the landing. Once we landed and shut down, we talked about the flight, logged the time in the book, and headed to hangar 1 for the start of the factory tour. (Note: The Rotax 916is engine in the aircraft I flew was on loan from Rotax. Sling was asked to put 2,500 hours on the engine in all conditions and then return it to Austria, where it would be torn down and inspected. The 916is is a replacement to the previous version 915is and came out earlier last year. Most current Slings have the 915is engines and are only now starting to show up with the 916is. The difference between the two is approximately 20 more HP for the first 5 minutes and an increased TBO from 1200 to 2000 hours.)
The factory consisted of multiple hangars divided into specific production areas: Parts manufacturing, sub-assembly, final assembly, Upholstery, stray shop, quality control, stores, kit packing, and AMO. (Aircraft Maintenance) Sling has acquired additional facilities off-site to handle expansion, and the upholstery division had been moved to that off-site facility.
Each area of production had people busy making airplanes—not only the Sling TSi but some of their other models. The Sling TSi high-wing, currently sold out, was also in production. The facilities were clean, organized, and busy. There was no question they were trying to keep up with their rapidly increasing production requirements.
As you know, we also have two other members building their own Sling TSis. Unlike my build assist, which starts in August with Evan Brunye in Boise ID, they are building the aircraft themselves. I visited their builds and was very impressed at the progress and build quality. I estimate both Aaron Granger and Eric Cadorette are about 70-75% complete, and I am very much looking forward to seeing their completed Sling TSis.
In closing, I was very fortunate to be able to visit the Sling Factory in Johannesburg as well as previously The Airplane Factory in Torrance. Sling has designed an incredible experimental aircraft in the TSi and powered it with a very reliable, technological, and powerful Rotax engine. The aircraft’s beauty, uniqueness, reliability, and performance capabilities will undoubtedly make huge inroads into the Experimental community, and I am very excited to be a part of that.
I want to thank Aaron and Eric for inviting me over to see their builds and for our phone discussions on all things Sling. I would also like to thank Jonathan Shaw at Sling South Africa for the TSi flight and the factory tour. I was very impressed by his knowledge and love for Sling. Lastly, I would like to thank Edward Hefter at the Airplane Factory for his assistance in my build order, multiple changes and for passing much of his knowledge of Sling down to me. If anyone is interested in building a Sling, Edward is the US point of contact.
