“RANS is back!” said many ultralight enthusiasts when the company offered their production version of the S-17 Stinger in September, 1999. Now the Kansas company has reaffirmed their commitment to the ultralight community by offering an enlarged S-17 with an added, tandem seat. Welcome to the S-18 Stinger II. Of course this isn’t the first ultralight trainer from RANS. They continue to sell their S-12XL Airaile 2-seater. Others may observe that the S-6 Coyote 2-place can be built to operate within the limits of the Part 103 training exemption. But when RANS first talked about their single-place Stinger – the prototype model that was never marketed – the company had been going in another direction. In those days the apparent darling of the company was the S-16 Shekari that is more accurately described as competition for Van’s RV series than as an ultralight. RANS president Randy Schlitter was able to see that ultralights didn’t simply grow up and become “light aircraft.” And, since Schlitter wants a share of the ultralight community, the S-17 single-place Stinger was his 1999 entry to entice ultralight flyers to the RANS brand name.
Ultralight Trainer from RANS
Seating | 2, tandem |
Empty weight | 478 1 |
Gross weight | 920 pounds |
Wingspan | 31 feet |
Wing area | 152 square feet |
Wing loading | 6.1 pounds per square foot |
Length | 22 feet |
Height | 6.75 feet |
Kit type | Assembly kit of Quick-Build kit |
Build time | 200 or 100 hours |
Notes: | 1. as published with standard Rotax 503 |
Standard engine | Rotax 503 |
Power | 50 hp at 6,500 rpm |
Power loading | 17.7 pounds per hp 1 |
Cruise speed | 70 mph |
Never exceed speed | 90 mph |
Rate of climb at gross | 500 fpm 1 |
Takeoff distance at gross | 330 feet |
Landing distance at gross | 200 feet |
Notes: | 1. as published with standard Rotax 503 |
Standard Features | Dual center-mounted joysticks, dual rudder pedals, dual throttles, push-button lever flaps, trim, heavy-duty 4-point seat belt, hand-lever brakes with parking brake feature, nose pod, short windscreen. |
Options | Extended-to-the-wing windscreen, 65-hp Rotax 582 or 81-hp Rotax 912 engine, complete instrument package, electric start, saddle bags, quick-build option to cut build time in half, custom colors, factory-painted boom, second 9-gallon fuel tank. |
Construction | Aluminum tubing wings, tail, and boom; welded steel fuselage; Dacron® sailcloth wing and tail covering. |
Design
Cosmetic appearance, structural integrity, achievement of design goals, effectiveness of aerodynamics, ergonomics.
Pros - RANS is known for distinctive designs and the S-18 Stinger II continues the trend. Follows closely in the tradition of the Drifter with front pilot seated ahead of wing. Nose and sweeping windscreen please the eye (and many buyers). Very sturdy welded steel fuselage. Two- seater lands even better than the S-17 single. Long established company, an industry leader.
Cons - Wide open cockpit even with windscreen and pod; not everyone will like it. Tandem seating is not preferred by many instructors. While the same basic design as the single-seater, the S-18 is 220 pounds heavier on 25 more square feet of wing; it requires more attention.
Systems
Subsystems available to pilot such as: Flaps; Fuel sources; Electric start; In-air restart; Brakes; Engine controls; Navigations; Radio; (items covered may be optional).
Pros - Flaps on the S-18; were not on the single-seat S-17. Parking brake on the joy stick-mounted lever which slows both wheels fairly effectively. Trim is easily reached below your left thigh. Good engine access, in fact, most parts of the S-18 are open to inspection - a good thing overlooked on more enclosed ultralights.
Cons - No in-flight starting; only option is electric or starting before being seated (though factory has been asked to add remote pull starting). Trim was completely ineffective on my test flight (a rigging error only). Nondifferential braking.
Cockpit/Cabin
Instrumentation; Ergonomics of controls; Creature comforts; (items covered may be optional).
Pros - Excellent instrument pod; good access and readability, making good use of space. All controls within an easy grip (though I stretched a bit to fully retract the flaps). Seat backs adjust through a good range as does fore/aft position. Seats look small but felt fine for an hour and a quarter flight. Windscreen worked well in front seat.
Cons - Entry is trickier than the single-seat S-17; you have to duck around the (optional) windscreen. Seats are rather minimalist for some large Americans (though you're held securely with those enormous seat belts). Rear seat is said to be quite windy. Rear seat has no engine controls (except throttle).
Ground Handling
Taxi visibility; Steering; Turn radius; Shock absorption; Stance/Stability; Braking.
Pros - Improved clearance over the single-place S-17 thanks partly to larger tires; good for most off-field landings. Slab main gear felt strong, good for training duty. RANS-brand full swivel tailwheel is excellent. Superb visibility in nearly all directions from front seat. Brakes proved reasonably effective.
Cons - Rear seat visibility is restricted; best occupied by an experienced instructor or a passenger. Heavier S-18 brakes slower than S-17. Turn radius is wide until you break the full swiveling tailwheel loose. Though this is a docile taildragger, they all take more attention than tri-gear.
Takeoff/Landing
Qualities; Efficiency; Ease; Comparative values.
Pros - Takeoff and landing visibility doesn't get any better (especially without the optional windscreen). Approach speeds can be slow for smaller fields. Flaps help make steep approaches without speed buildup; lever works well with easily felt position detents. Clearance shouldn't be a problem except on very rough fields.
Cons - Takeoff roll is a little long even with the 65-hp Rotax 582 (50-hp Rotax 503 not test-flown). Slips are less effective than on ultralights with more side area.
Control
Quality and quantity for: Coordination; Authority; Pressures; Response; and Coupling.
Pros - Adverse yaw was moderate (though with more hesitation than the S-17 single-place). Reversing 45° bank turns went well to good angles. Higher wing loading of the 2-place S-18 produced crisp handling response. Handling in crosswind conditions should pose no problem.
Cons - Rudder pedals were rather stiff on the test S-18 Stinger II while the stick was nice and fluid, making controls feel less harmonious. Test aircraft had a slight turn in it which can be remedied by rigging adjustment.
Performance
Climb; Glide; Sink; Cruise/stall/max speeds; Endurance; Range; Maneuverability.
Pros - Climb was strong in the 582 model; RANS offers the 912 as well. Cruise is speedy, and 80 mph speed is normal, says the factory (I flew it a little slower but that may just be my style). Sink rate averaged about 500 fpm, a respectable number. Even in steep turns, the Stinger held altitude with 5,000 rpm, another reasonable figure.
Cons - Equipped with the base 50-hp Rotax 503 model, climb could be a bit weak. Sold without windscreen, which reduces top speed 10 mph. Fuel consumption won't win any awards.
Stability
Stall recovery and characteristics; Dampening; Spiral stability; Adverse yaw qualities.
Pros - All stalls showed benign qualities with no significant breakthrough; full-power stalls kept climbing 500 fpm (with 65-hp Rotax 582, as tested). Longitudinal stability tests were positive. Lateral stability was good. Steep turns held bank angle easily (even without adding excess power). Seat restraint system is the most robust in ultralight aviation.
Cons - Despite the little vortex generators on the windscreen, the tail still had a mild shudder on takeoff, a slow-speed event I didn't notice at cruise. Adverse yaw exhibited more lag than the S-17 (though still quite good). Throttle response noses over the S-18, typical of high-thrust ultralights.
Overall
Addresses the questions: "Will a buyer get what he/she expects to buy, and did the designer/builder achieve the chosen goal?"
Pros - RANS' price list makes it easy with "minimum flyable" and "nicely equipped" prices: $16,900 with 50-hp 503 and some instruments or $19,335 with 65-hp 582 and a full panel. FAA 51% approval received. RANS is one of the most secure businesses in ultralight aviation.
Cons - Quick-build kit adds $4,600 expense to cut build time in half (but still may be worth it to many who prefer flying to building). Design is similar in many ways to more proven Drifter (though with desirable differences). Watch options to stay within Part 103 exemption if 582-powered; climb with the 503 may be too weak in some locations.