The pretty blue Eros with bright yellow stars on it is no ordinary ultralight. On second thought, “ordinary” and “Eros” aren’t words that go together. Of those aircraft designed by Wayne Ison and his former TEAM team, this model is the hottest of the fleet. I believe I’ve flown all Ison designs that were put into manufacture and Eros is one of my favorites. (In truth, it’s a tossup between the Max-103, Air-Bike, and the Eros.) The Legend of Davy Lee For this month’s pilot report, I got the chance to fly a special Eros, a Grand Champion at Sun ‘n Fun ’98 in the Lightplane Class. It belongs to owner/builder/pilot Davy Lee Cooper and it represents my second review of an Eros. Cooper’s Eros is Rotax 503-powered as was the earlier Eros I flew, but both are derived from the Eros-preceding V-MAX with a Half VW engine. Without a doubt the Rotax 503 is more energetic, yielding better climb rates and somewhat faster speeds.
Proven Design; Ison Aircraft’s Eros
|Empty weight||345 pounds|
|Gross weight||625 pounds|
|Wingspan||26 feet 6 inches|
|Wing area||118 square feet|
|Wing loading||5.3 pounds per square foot|
|Kit type||All components or Plans only|
|Build time||300-400 hours|
|Standard engine||Rotax 503|
|Power||46-50 hp at 6,500 rpm|
|Power loading||12.5 pounds per hp|
|Cruise speed||60-85 mph|
|Never exceed speed||110 mph|
|Rate of climb at gross||1,200 fpm|
|Takeoff distance at gross||150 feet|
|Landing distance at gross||250 feet|
|Standard Features||Fully enclosed cockpit, removable wings, steerable tailwheel, Rotax 503, 4-point seat restraint, in-flight trim, remote choke, full shut-off, Kevlar prop spinner, rounded wing tips, fiberglass cowling and boarding step insert, fabric, adhesive, and assembly hardware.|
|Options||Engine mount, instruments, plans-only ($175), convertible swing-over open canopy, steel gear parts, wheel pants, second 5-gallon fuel tank, and partial kits.|
|Construction||Wood airframe, fiberglass cowling, steel components, fabric wing, tail, and fuselage coverings, AN hardware. Made in the USA.|
Cosmetic appearance, structural integrity, achievement of design goals, effectiveness of aerodynamics, ergonomics.
Pros - Classic V-MAX design redone with a Rotax 503 engine and snazzy paint job transforms the basic aircraft into a zippy flyer. Well-proven design with solid safety record. Wood construction felt by many builders to be an easy medium. Single-place design lets you explore sport flying as you wish.
Cons - No 2-seater is offered. Wood requires extra maintenance to stay airworthy as it ages. Resale may be slowed by buyers' interest in two seats and the wood structure may put off some customers.
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 - Simple aircraft with few systems installed (because it is FAA-registered, you could add some). Heel brakes were effective and functioned well. Fuel supply was easily determined. Refueling is easy. All controls and instruments were accessible. Choke mounted by throttle.
Cons - Some Eros models have no trim; Cooper added one and it would be useful on longer flights. No flaps available. Engine access requires removal of the fiberglass cowling. Limited room to add navigation or radios to the instrument panel.
Instrumentation; Ergonomics of controls; Creature comforts; (items covered may be optional).
Pros - Some Eros models have no trim; Cooper added one and it would be useful on longer flights. No flaps available. Engine access requires removal of the fiberglass cowling. Limited room to add navigation or radios to the instrument panel.
Cons - Entry may require a technique for less flexible pilots. Radios and controls mounted on side walls restrict pilot legroom. Seat and pedals don't adjust except during building. The lack of cabin vents on this full enclosure made for an unacceptably warm cockpit in Florida's heat.
Taxi visibility; Steering; Turn radius; Shock absorption; Stance/Stability; Braking.
Pros - Tailwheel control was highly responsive; made for easy taxiing. Turn radius is tight, allowing good maneuverability. Very stable stance on ground; gear feels very solid. Visibility is excellent even with the full enclosure. Top of canopy is opaque, keeping the sun off your head.
Cons - Rudder pedals are responsive enough that you need to control movements during takeoff and landing to avoid ground looping. Suspension is limited to air in the tires; gives a firm ride on unpaved runways. Braking effectiveness was modest and heel brakes provide less feel than toe brakes.
Qualities; Efficiency; Ease; Comparative values.
Pros - Takeoff is very fast with the Rotax 503. Visibility throughout takeoff and landings is very good. Approaches can be done at 45 mph, though 55 to 60 mph is recommended at first. Aircraft retains energy better than simpler miniMAX models. Slips were effective. Excellent controls for crosswind operations.
Cons - The Eros glides well enough that you need to plan approaches better than in draggy ultralights. No flaps so you must use slips. You must keep rudder control inputs smooth to avoid ground loops. Soft- or rough-field operations are less desirable due to wheel pants and low tail clearance.
Quality and quantity for: Coordination; Authority; Pressures; Response; and Coupling.
Pros - Wonderful controls; Eros handling is as good as all Wayne Ison designs. Crosswind landings benefit from authoritative controls. Aileron response is quite lively and roll is brisk. Pitch is light and requires almost no muscular exertion. All control maneuvers exhibited excellent precision.
Cons - The Eros is a little pitch-sensitive and responds quickly to throttle inputs. Adverse yaw was present. Harmony was adequate but not perfect; the rudder was lighter than ailerons and you must adapt.
Climb; Glide; Sink; Cruise/stall/max speeds; Endurance; Range; Maneuverability.
Pros - An Eros with Rotax 503 power is plenty of power. I noted a significant improvement over the earlier Eros powered by a Half VW engine. Climb is stunning, perhaps 1,500 fpm. Sink rate and glide benefit from smoother lines; sinks about 500 fpm. At about 5,200 rpm, noise and vibration were lessened yet speed held at better than 70 mph.
Cons - Endurance is somewhat lower due to the thirstier engine. Two-stroke noise is a whine versus the VW's growl. Sink rate is only average (though better than some miniMAX models). Vibration was more visible than with the Half VW engine.
Stall recovery and characteristics; Dampening; Spiral stability; Adverse yaw qualities.
Pros - Stalls felt modest and came in the mid- to high-30s mph. Stall response was predictable and mild. Power-on stalls went to exciting deck angles but the Eros resisted breaking over. Controls retain authority down to slow speeds.
Cons - Light pitch caused me to fly the stick and ignore the trim, however this makes for more pilot workload (on longer flights, the installed trim would be useful). Longitudinal stability checks by throttle movements produced noticeable change.
Addresses the questions: "Will a buyer get what he/she expects to buy, and did the designer/builder achieve the chosen goal?"
Pros - If you want snappy performance and handling in a package that'll run $10,000, the Eros is a recommended choice. Doing business with Wayne Ison's team brings enthusiastic remarks from owners. Manuals are good and proven by lots of owners. Safety record is respectable.
Cons - Eros cannot qualify for Part 103 operations, which means you'll have to N-number it and get a pilot's certificate to fly it. Build time is average for construction kits but will take all of 400 hours. Eros performance and handling suggests it may not be the best Ison Aircraft choice for a starter airplane.