Sting S4

The TL-2000 Sting S4 is TL-Ultralight's best-known model and has been in production since 2010. It is the fourth generation of the Sting family, which began in 2001/2002 with the TL-2000 Sting Carbon – in Germany that first generation is listed as the TL-96 Sting, although the relationship between the designations cannot be established unambiguously from the available sources – and progressed via the TL StingSport for the US LSA market (2004 to 2006) and the Sting S3 (2007 to 2009) to the S4. The Sting itself is descended from the TL-96 Star, the company's first composite low-wing design.

The S4 is a two-seat side-by-side low-wing aircraft with a primary structure of carbon and glass fibre sandwich over a foam core. The factory manual quotes a 9.12 m span, 6.20 m length, 2.05 m height and 1.12 m cabin width, with an aspect ratio of 7.69 and a 12:1 glide ratio. Engines are the 80 hp Rotax 912 UL or the 100 hp Rotax 912 ULS, optionally the 115 hp turbocharged Rotax 914 or the 100 hp fuel-injected 912 iS. British approved configurations list the TL-Ultralight PowerMax three-blade variable-pitch propeller at 1,748 mm or the DUC Swirl-3 fixed-pitch propeller at 1,730 mm with a 2.43:1 reduction. The gear is fixed tricycle with a steerable nosewheel.

Weights depend on the approval: 450 kg as a classic ultralight, 472.5 kg with an emergency parachute system, and 600 kg in the LSA / 600 kg category. The British type data sheet gives a typical empty weight of 380 kg for the 600 kg version, with 382 kg the maximum at first registration, while the German dealer quotes from 325 kg. Fuel capacity is 77 litres in the fuselage tank, or 121 litres with the two 22 litre wing tanks, of which 5.6 litres are unusable. Fuel is unleaded premium petrol of at least 95 RON to EN 228 – the US manual states "91 octane" on the American AKI scale, which corresponds to 95 RON and must not be confused with regular grade; the manual restricts AVGAS 100LL to less than 30 percent of operating time.

In the air the S4 is a fast tourer. The manufacturer quotes 180 to 250 km/h cruise, and the LSA manual lists a maximum level speed of 128 KIAS (about 237 km/h) at maximum continuous power at sea level. VNE is 290 km/h IAS in the ultralight manual and 153 KIAS in the 600 kg version, and best climb reaches 5.58 m/s at 130 km/h. Range is 840 km without wing tanks and 1,370 km with them, in both cases with no wind and no reserve. The price of that performance is approach speed: the ultralight version stalls at 80 km/h IAS clean and 65 km/h IAS with landing flap, the 600 kg version at 49 and 43 KIAS respectively. That is entirely manageable but demands accurate approaches and flare technique. Aerobatics are prohibited, maximum bank is 60° and load factors are +4/-2 g flaps up.

Strengths: a lot of speed for little fuel (the manufacturer quotes 16.2 l/h at 75 percent power), modern equipment, a broad used market thanks to high production numbers, and type support from Wezel Flugzeuge in Damme. Weaknesses: published data is inconsistent – factory manual, website and dealer material disagree on fuselage length (6.20 to 6.65 m) and wing area (10.8 versus 11.1 m²), and no service ceiling can be reliably sourced from the accessible documents. Baggage is limited to 25 kg and occupants to 200 kg combined, 100 kg per seat. The Sting S4 is therefore an aircraft for pilots who want to cover distance and arrive earlier – not the obvious first ultralight for a freshly licensed pilot.