To many observers, SlipStream Industries is a different ultralight company. As they exhibit in the ultralight areas of big airshows, we know their heart is in the right place (as far as Ultralight Flying! readers are concerned anyway). But they also make twin-engine aircraft. One way SlipStream distinguishes itself among all light aviation enterprises is by offering not one, but two twin-engine aircraft. The line-up includes the SkyBlaster, which was recently renamed Gemini Twin to differentiate the name from SkyQuest, SlipStream’s other twin. Gemini Twin is a rare fore-and-aft arrangement using two 50-hp Rotax 503 engines. Certainly it is the only one with this configuration in the ultralight field and it draws some analogy to the famous Cessna Sky Master. Hence its closely related former name. Before the SkyBlaster/Gemini Twin, SlipStream developed and still sells another twin, the SkyQuest. Like its sibling, this twin aft engine pusher design uses the ultralight-standard 50-hp Rotax 503 dual carb as powerplants.
Slipstream Industries’ Simple Scepter
Empty weight | 425 pounds |
Gross weight | 662 pounds |
Wingspan | 30 feet 8 inches |
Wing area | 179 square feet |
Wing loading | 3.7 pounds per square foot |
Length | 18 feet 7 inches |
Height | 6 feet 3 inches |
Kit type | Assembly kit |
Build time | 100-150 hours 1 |
Notes: | 1 Quick Build kit can lower assembly to 30-50 hours, says factory. |
Standard engine | Rotax 447 |
Power | 40 hp |
Power loading | 16.5 pounds per hp 2 |
Cruise speed | 55 mph 2 |
Never exceed speed | 120 mph |
Rate of climb at gross | 750 fpm 2 |
Takeoff distance at gross | 100 feet |
Landing distance at gross | 100 feet |
Notes: | 2 With optional 50-hp Rotax 503 engine cruise is 70 mph, climb is 1,000 fpm, and power loading is 13.2 pounds per hp. |
Standard Features | Choice of yoke or center stick, 40-hp Rotax 447 with B-gearbox, steerable nosewheel, 5-gallon fuel tank, aluminum wheels, nose pod, instrument panel, windscreen, fiberglass seat with upholstery, shoulder belt, 2-blade wooden prop, mechanical brakes. |
Options | Flaps, 50-hp Rotax 503 or 65-hp 582, 45-hp Zanzottera MZ 201, instruments, hydraulic brakes, electric starter, electric trim, floats, strut fairings, wheel pants, additional instruments, tundra tires, adjustable seat, droop tips, 10-gallon fuel tank, and ballistic emergency parachute. A Quick Build kit taking 30-50 hours is available. |
Construction | Aluminum 6061-T6 airframe, fiberglass fairing, Dacron® wing coverings. Made in the USA. |
Design
Cosmetic appearance, structural integrity, achievement of design goals, effectiveness of aerodynamics, ergonomics.
Pros - Most ultralight-like of the SlipStream designs. Based on the SlipStream Genesis, which has proven a reliable workhorse design. Capable of carrying lots of weight. Well-understood construction of 6061 T-6 aluminum and Dacron wings; eases building effort.
Cons - Cannot qualify under Part 103, well over weight definition. Open cockpit is not for everyone (though the Genesis is essentially the same aircraft for those who want cabins). Simple design unless you add options.
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 - Numerous systems available owing to the Genesis heritage: electric start and/or trim, flaps, hydraulic brakes, amphibious floats, and ballistic parachute worked out with factory. Easy refueling and no cabin to retain fumes. Good engine access. Mechanical brakes are standard.
Cons - Adding systems available because a Scepter is an N-numbered aircraft will degrade performance, requiring larger engine. Nondirectional brakes (though a builder could add them; sufficient room by pedals).
Cockpit/Cabin
Instrumentation; Ergonomics of controls; Creature comforts; (items covered may be optional).
Pros - Very simple entry and exit. Plenty roomy for large guys; no wonder, design created by bigger pilots. Supportive seat with standard upholstery. Standard shoulder belt (3-points). Large windscreen keeps airblast off the pilot very well, though lots of air still flows.
Cons - Seat adjustment is only available as an option. Panel switches may be a reach for smaller pilots; aircraft is designed for large people. No cargo/baggage area unless builder adds structure for this purpose. No doors available on this open design.
Ground Handling
Taxi visibility; Steering; Turn radius; Shock absorption; Stance/Stability; Braking.
Pros - Very good visibility, even for takeoff, except up and behind. Good nosewheel steering, quite precise and with light pressures. Standard brakes make hard surface runway operations reasonable. Strong 1.5-inch gear legs. Good clearance for off-field landings; factory states it makes a good bush plane.
Cons - Turn radius was not particularly tight and no differential brakes to assist compact maneuvering. Brakes were only modestly effective (though sufficient in this slow-landing aircraft); stronger hydraulic brakes add unnecessary weight. Shock absorption limited to gear leg flex.
Takeoff/Landing
Qualities; Efficiency; Ease; Comparative values.
Pros - Takeoff roll is quite short; roughly the same regardless of engine (I was told) no doubt thanks to the broad wings. Good pretakeoff and landing approach visibility. Approach can be done with slow speeds, reducing field size needed. Crosswind capability seemed good. Sink rate is relatively low.
Cons - No underside fairing (floor) allows runway grit to enter the cockpit (though it didn't get in my eyes). Flaps not standard and lack of vertical area makes for less effective slips. Bleeds off energy rather quickly. Without optional flaps, not much potential to adjust for short or soft fields.
Control
Quality and quantity for: Coordination; Authority; Pressures; Response; and Coupling.
Pros - Good overall response with no one quality better than another. Capable in crosswinds (with limits, of course). Yoke input will be familiar to general aviation pilots transitioning to ultralights via the Scepter; I'd have preferred the joystick; you can choose. Control balance (how all surfaces relate in feel) was quite good.
Cons - Turn initiation and response were adequate, but turn termination was sluggish in my experience; rollout to a precise heading was less than optimal. Overall predictability was also confused by this quality. I also found pitch to be odd, but factory says this is due to a yoke shaft lubricant.
Performance
Climb; Glide; Sink; Cruise/stall/max speeds; Endurance; Range; Maneuverability.
Pros - With 40-hp Rotax 447 engine, the Scepter does surprisingly well, holding altitude at around 5,000 rpm. Sink rate is slightly above average among all ultralights. Cruises 55-60; Rotax 503 pushes the Scepter to an easy 70-mph cruise. Low-over-the-field flying is quite pleasant in the Scepter. High 120-mph Vne (unverified).
Cons - The Scepter with standard Rotax 447 engine climbs 750 fpm per factory specs but doesn't sustain as strongly once altitude increases. Choosing a 50-hp Rotax 503 or 45-hp MZ 201 to boost performance comes at additional cost over the excellent base price, yet I recommend them for large pilots or high field elevations.
Stability
Stall recovery and characteristics; Dampening; Spiral stability; Adverse yaw qualities.
Pros - Stalls were quite low, no doubt due to the large wing (179 square feet). Dutch rolls went smoothly to low angles (thanks partly to the good control balance). Control pressures are middle of the range, which should please a large number of pilots. Stable in hands-off flying.
Cons - Pitch seemed unusual in some regimes. No problems discovered but the feeling was not optimal. Factory blames this on a sticky lubricant on the yoke's linkage shaft. Significant adverse yaw (not unusual for big ailerons). Some nose-over tendency on power-up.
Overall
Addresses the questions: "Will a buyer get what he/she expects to buy, and did the designer/builder achieve the chosen goal?"
Pros - Good transition plane for general aviation pilots who want a fun machine in the ultralight experience. Prices start at $10,995 including engine and propeller. Quick Build kit cuts assembly to 30 to 50 hours, says factory. Simple construction means easier repairs if needed. Company is becoming a well-established player in light aviation.
Cons - Aircraft may seem heavy or big for an ultralight (though performs well thanks to large wing). You must N-number and have an FAA pilot's certificate. I haven't heard much about factory support or dealer network.