Full marks for Eurofox
Depending on what you’d call a different model, over thirty separate aircraft types have been based on the original Avid Flyer two-stroke powered ultralight aeroplane. They all look a little alike and all have folding wings, which can save you a lot of hangarage and also offers the option of taking your aeroplane home on a trailer. The 30-plus types include the popular homebuilt Kitfox, the Australian-made Skyfox which is now out of production, and also, as we discovered at Natfly in Temora, the Slovakia-built Eurofox LSA (light sport aircraft,) over 300 of which are now flying, including 12 in Australia.
So what’s so singular about this one?
Well, that question will get you a well-informed earful any time from Tony Brand at Horsham Aviation Services, who’s about to take me on a walk-around – and to explain why he chose Eurofox when he started looking for an aircraft to broaden his range of products and services. He knows his product and he’s now Eurofox’s Aussie distributor.
On the ramp, like many of its competitors, the Eurofox looks a bit like a modernised version of the 1950s high-wing “rag ‘n tube” monoplane, the most visible difference being distinctive looking full-span “flaperons.” These sit slightly below and behind the wings’ trailing edges and give you the feeling this is going to be a great little aircraft to control at low airspeeds. If you’re unfamiliar with the term, it basically means they’re full span flaps, which also work differentially as ailerons whether they’re extended or not. And because they’re full span they also don’t need high flap angles to do their job, so 15° is their maximum deflection.
And that’s where you start to notice the real differences, because there are five hinges on each flaperon, they’re all chrome-moly steel, as is the primary structure, and the flaperons are composite rather than fabric, which means moisture can’t get in and cause aileron imbalance or other unwanted problems.
“That’s why we picked this aircraft to sell, because it’s so beautifully built,” says Tony. “All the tubes in the open truss fuselage structure are actually sealed airtight and with lots of triangular bracing; there’s not one tube that has a hole drilled into it anywhere, and if they want to attach something they’ve welded on a tang and attached it to that. The steel tubes actually have corrosion inhibitors in them, where in a lot of aircraft of this general type you see open-ended tubes, or tubes with screw holes in them, and anyone who’s been in the industry for a few decades knows what it’s like with Piper Colts, Tripacers and Cubs. One screw hole with a screw in it is enough to let moisture in and in later years you need X-rays to check the integrity of the tube. So these aircraft should be around for a lot of years.”
The main gear comprises two separate and rugged-looking fibreglass undercarriage legs, attached by bolts in shear at the structural centre of the aircraft, just behind the doors, where the wing struts are also attached. The raked-back strut arrangement offers unobstructed entry through the doors, which open upwards. The doors can be opened in flight and “fly” up to a position just below the wing which is excellent for photography and supply dropping. Opening and closing the door is best done at around 60 knots. Alternatively either or both doors can be completely removed by pulling out a single bolt. Gas struts enable door-open taxying for a hot day.
The door arrangement, along with the transparent lower doors, gives great downwards vision on the ground, and unobstructed photography in the air with a door open.
The tail unit is fabric over a “lattice-work” tube frame. The tricycle nose gear is of steel construction with rubber cushions attached to the main structure just behind the firewall and engine mount frame. It incorporates a pedal-steerable nosewheel.
Around the back, there’s a fibreglass tail protection skid which is so firmly attached to the aircraft structure that in the tail dragger version the tailwheel assembly is simply bolted onto the skid.
The Stits polyester fabric skin is finely finished in a two-pack polyester paint, which Tony figures will last something like 50 years if it’s hangared. Inside the wing are all-aluminium ribs and spars. There’s a composite leading edge for bird strikes.
Fuel is in two 40 litre welded aluminium wing tanks and a 6 litre central connecting tank, providing a total usable fuel capacity of 85 litres, with 1 litre unusable. Refuelling is conventional over-wing, there is only one fuel drain in the 6 litre centre tank, and the top cowl is secured by a dozen Dzus fasteners and is quick and easy to remove if you need to check it hasn’t become a protected bird habitat overnight.
The three-bladed FITI Disign ground adjustable propeller is set to achieve the best compromise between takeoff and cruising performance. Cruise speed figures in our table is based on 75% power, 5,200 rpm, which will achieve 110 KTS TAS. Cruising power can be varied between 4,500 and 5,500 RPM (maximum continuous power) depending on whether you’re in a hurry or are happy with a more economical cruise. And as we’re about to find out the Eurofox has plenty of takeoff performance to spare.
Cabin ventilation comes from panel vents connected to low-drag NACA intakes on either side of the fuselage, and also by openable rotatable vent-scoops in either window. There’s a transparent cabin ceiling, tinted nicely to prevent glare and UV but still offering good upward vision in turns.
Attached to the fuselage structure the composite seat pan is in a fixed position but can be adjusted for pilot height be adding or subtracting seat and seat-back cushions that come with the aeroplane, and are held in place by Velcro. The seating pan is composite, and when it’s removed you have access to all the control systems including the rudder control cable runs. The rest – flaperons and elevators – are all operated by beautifully-engineered push/pull rods.
There are pictures of a two-tonne load sitting in the seat pan and the undercarriage splayed right out. While you probably wouldn’t want to try anything with a two tonne load, it all amounts to a very strong and survivable aircraft, especially because just behind the windscreen it has a V structure of two bars running from near the centre of the lower windscreen, diagonally up to the wing roots. So if you happen to find yourself approaching a power line in flight, it should be deflected above your head. We’ve heard of a Skyfox Gazelle (which has the same feature) encountering a power line, but the occupants walked away and the aircraft was flying a week later.
Unusually, there’s a 12v external power inlet for charging the battery and finding your way around the avionics. It’s optional and comes with a ground power plug if you order it, and it’s a good idea.
So let’s see how it flies and handles.
Getting in and out is painless because the struts are way back out of the way, and I find the easiest way is to sit on the seat from outside, then swing your legs up with the stick held back. The fuselage itself has been generously widened to 44.1” (1.12m) with a cabin height offering ample headroom, and blimey! This aircraft has an optional glass cockpit, which we’ll take a good look at when we’re cranked up.
Standard seating accommodates my height, and it’s all very comfortable when seated. There’s elevator trim and press-to-talk switches; the elevator trim being via a cable connected directly to the trim tab, and the flaperon lever is right next to the pitch trim, which turns out to be convenient because flap extension calls for a quick trim change even though control forces are light.
There’s a four point harness anchored to the frames at the rear and under the seat, and whole interior is an attractive velour.
By now the optional electronic flight instrument system (EFIS) has lit up and it’s delightfully simple and functional. If you’re not accustomed to the conventional flight instrument “six-pack” instrument display, you might now never need to be. Five of the six primary functions – airspeed, altitude, artificial horizon, slip/skid and horizontal situation – and clear and legible. Altitude and airspeed are displayed both on vertical tapes and in digital windows. There are two spare data spaces that can be set to display two selected indications of your choice from a small menu. I’d be going for VSI (which is one of the usual six anyway) and the air data group – outside air temp, density altitude, and true airspeed. A voltmeter is also a good idea but I’m sure that could be wired in to a separate gauge if required.
Dynon offers a range of options including a 7” (17.7 cm) or 10” (25.4 cm) display at $2,700 and $3,600 respectively and there are tempting add-ons such as synthetic vision and engine management system options: “I’d suspect you could spend up to $5,000 to put everything in, but every customer’s different so we encourage people to make their choices very carefully,” says Tony.
There’s a Vernier throttle control, offering the option of turning the knob for fine tuning or depressing the button and pulling or pushing for coarser throttle movements. This is a common fit on GA aeroplanes, and on Rotax engines it helps with their tendency to need a lot of throttle retardation before much happens. Carb heat is to the left of the throttle and the brake lever is to the right. Mixture control is automatic on Rotaxes so you won’t have much luck trying to lean it out with the (red) brake handle.
The pre-start checklist is comprehensive but quick because everything’s so well labelled. There’s a main fuel cock which must be on all the time the engine’s running, and one for either tank so you can select the one with the most fuel at any time. They should be turned off if you’re parked on a transverse slope to prevent fuel cross-draining.
Using choke for the cold engine, it’s important to remember to un-choke after start or your engine won’t run comfortably if at all especially on takeoff. The aircraft starts rolling at idle on the smooth bitumen, nosewheel steering is responsive, and braking where needed is smooth and effective. The brakes are non-differential and controlled by a hand lever close to the throttle, making it easy to move your hand from throttle to brake after touchdown without searching for it. It also acts as a park brake if you pull it on then turn to lock it – turning the other way to release.
Lined up and almost ready to go we apply full flap which is unusual in any aircraft, but remember in this one it’s only 15°. The rudder becomes fully effective as soon as the power comes up. There’s about 10 knots on the nose with a slight right hand crosswind component. At around 40 KIAS the aircraft seems to sniff the breeze and start flying without much encouragement in an incredibly short distance, and accelerating while also climbing very positively. We hold the nose down to gain the recommended 65 KIAS initial climb speed. Flaps are retracted and we’re climbing at about 1000 fpm. If you need best climb angle to clear obstacles, 60 KIAS is recommended and you need to remember to get the flaps up before reaching max flap extended speed of 81 KIAS.
Settling into what’s more or less a cruise climb flapless at 79 KIAS we’re still climbing at about 900 fpm. I slip a headset off and find cabin noise would be moderate enough for voice communication. Pilot field of vision is good, and the instruments and controls are all logically-located. The aircraft is very stable but responsive with light control forces and good trim response, and will quickly settle to fly almost hands-off. Stable trimmed-out flight at various speeds down to 55 KIAS still feels comfortable and with excellent control responses.
Once trimmed the aircraft stabilises well in turns, and I try a 360 ‘rate 3’ (360°/min) turn using the flight instrument display to maintain a constant bank angle and turn rate. The glass-cockpit instruments are accurate and easy to use, they accurately depict the flight attitudes and control responses, and we’re rewarded by a small burble as we complete the turn and fly back into our own (mild) wake turbulence.
As I’d expected, stall behaviour is mild and forgiving at any speed and configuration, and recovery is instant when you relax back pressure on the stick. Like most aircraft in this category there is no stall warning system in the basic aircraft. The optional Dynon EFIS has an Angle of Attack system, and generates an electronic noise in your headset. Even at full flap in a simulated glide approach with about a 20° sideslip, there’s a modest wing drop which is easily controlled with aileron as soon as the nose is lowered. I get the feeling that you could keep the wings level with aileron just about anywhere in the flight envelope, making this a very forgiving and foolproof aeroplane. Wings-level power off stall occurs at 36 KIAS, and even the pilot operating handbook (which reminds us that we shouldn’t be doing this in normal flight) simply recommends: “Lower the nose by pushing the control stick,” and “increase power.” The manual recommends a “minimum flight steady speed) of 43 KIAS, and 1.3 times stall speed is 46.8 kt.
The seating and cabin feel comfortable and un-cramped, and at a cruise speed based on 75% power (5,200 rpm,) the aircraft achieves 110 KTAS. (Maximum continuous is 5,500 rpm.)
The test aircraft could be described as “standard fit” and would retail about $92,000 + GST with VHF and moving map GPS. A Eurofox can also be fitted with an autopilot, but it’s best to order that with the aircraft because the factory can then weld in its servo mount brackets during construction. Autopilots have come a long way in terms of weight and performance since the 1970s and for touring, they’re a very desirable feature.
And the EFIS panel is much more than just an ornament. As most pilots increase their experience levels they consciously try to become proficient in handling their aircraft by reference to instruments – first because it’s a double check on what you’re doing, and second because you never know when it might get you out of a tight spot you shouldn’t have gotten into in the first place. This simple-looking instrument responds instantly to attitude changes, and is in fact a better depiction than you’ll ever get from the conventional six-pack panel. As long as you keep a lookout it will also get you inured to instrument flight so it won’t be a challenge if you ever decide you want to gain a rating later.
Back at Horsham we fly three approaches and landings, the third from a 500’ circuit and using 1.3 Vs (47 kt) as the reference speed, produced two very satisfying touchdowns on the centreline and no apparent white knuckles for Tony Brand.
Eurofox is a beautifully-built, nimble, friendly and satisfying aircraft to fly. I reckon I could teach my wife to fly in one if only she’d keep her eyes open!
Take a look at www.horshamaviation.com.au
