Australian Flying
March/April 2005
Flying Fox
Paul Phelan puts us in the see-through cockpit of the Foxbat aircraft - yet another choice to put you squarely above that highway crawl and get you to your destination in surprising comfort.
No, we're not urging you to rush out and buy a vintage MIG-15 Foxbat jet interceptor, even if you do have influential contacts in Moscow. Either as a kit or a factory-build, the new-generation Aeroprakt A22 Foxbat is certainly more affordable and far safer for your average low-mach recreational pilot, and the latter-day Foxbat shares a similar heritage to that of its namesake. Its design is the work of Yuri Yakovlev, formerly of the Ukraine's Antonov design department, which also produced the world's biggest aeroplane - the six-engined An-225 Mriya transport, with a 600 tonne maximum takeoff weight. (That's equivalent to about 1,333 Foxbats.)
We encountered the Foxbat at a fly-in at Cooma's Polo Flat airfield, where its happy owners Trevor and Leanne Mahoney had flown-in from Drouin South in Victoria, over 200 nautical miles of mostly alpine scenery, in little over two hours Among other first-glance impressions are the full-span 'flaperons,' ailerons which can be extended also to act as very effective flaps with 10 and 20 degree settings. There's also a clever and unusual nose wheel configuration, in which the telescopic nose strut is grease-damped, and the suspension is a pair of laminated fibreglass leaf springs, which act also as a scissor-link to transmit nose wheel steering. Because its elevators become effective and the Foxbat wants to fly at relatively low speed, it has a small protective tail wheel protruding from the aft fuselage. We're told (although we didn't try it) that the aircraft can easily be taxied in the three-point configuration, an advantage on rough and/or stony strips. The main gear is spring steel, and gives an excellent ride even on relatively rough surfaces. This and the brilliant low-speed flight characteristics we're about to discover, make it a very bush-friendly aeroplane.
Factory built or kit?
The aircraft comes either factory ready-built or in kit form, but the price difference means you don't save all that much doing it the hard way. If you do, there are pluses and minuses. On the plus side you can fly it at a higher gross weight 544 kg - 94 kg up on the factory-built certification, although several LSA manufacturers and their Australian reps are currently lobbying to have this anomaly reviewed in favour of factory certification. The downside is that you can't use it for training. The facts are that at 544 kg there's negligible performance loss, and you can legally earn enough fuel to fly a lot further from your departure point. In New Zealand, France and America, that battle has already been won and against CASA's current reform background, Australia's LSA movement is looking for the same outcome.
This is only the second "widebody" LSA we've reviewed. Lateral space is fifty inches across at the widest part of the bulged Lexan doors and perfectly ample at hip height. The semi-reclining seats are well shaped for comfort and have energy-absorbing foam under the cushions. Following some re-alignment of the instrument panel, height from the seat squab to the cockpit roof in the current model is an ample 38 inches, so there's also plenty of headroom. The reconfiguration doesn't restrict the forward view, because it merely brings the top of the panel in line with the cowling. Behind the seats there's a nylon fabric, zipped ‘suitcase' for luggage, which is convenient to reach in flight, and there's plenty of map stowage.
The gull-wing doors are piano-hinged at the top and can easily be removed for photography or hot weather living. They can also be removed before flight, but not opened in flight.
They're held open by a gas strut which over-centres as the door is pulled down and helps push it to the closed position. Both doors are fitted with a non-lockable latch, operable from inside and out. Access is exceptionally good and the doors fit well when closed. Adjustable air vents are mounted in the dished Lexan doors and exhaust-warmed cockpit air can be fitted if you’re flying in the cold country. The firewall is of alloy and stainless steel and is not soundproofed, but the noise-level is moderate if you use passive noise-attenuating headsets.
Construction
The wings, with about one degree of wash-out and a huge 9.97 metre span, are swept slightly forward to fine-tune the C of G position and to provide other aerodynamic advantages as well as improving the pilot's view upward and in turns. The main spar is of conventional D-box plus rear spar construction, with pressed Alclad ribs. The leading edge back to the rear of the D-box is Alclad-covered, the trailing edge and flaperons are fabric covered, and the wingtips are composite. The flaperons, operated by torque tubes, can be lowered to 10 or 20 degrees with an overhead lever like an Auster, if anybody remembers. The geometry of the roll control linkage provides significant differential effect to minimise adverse yaw, and a 1.9 cm slot between the flaperon leading edge and the wing adds a slotted flap effect. You do need to rudder the aeroplane in and out of turns, which may he why it has a slip/skid ball on either side of the panel.
For a while, Foxbat was offered with foldable wings until it was discovered that they added about 12 kg to empty weight and took longer to stow than simply removing them and placing them in a cradle on your trailer, which takes about half an hour. Fuel capacity is 92 litres in two wing root tanks of 46lit (44 useable) each. The filler caps are on the lop of the wing roots and you'll probably need a step to reach them comfortably. Two separate fuel cocks in the wing roots allow either or both tanks to be selected, and a single gascolator/water drain is located underneath the engine cowling. The control runs for the flaperons have foolproof quick-release fittings, and the fuel lines can also easily be fitted with quick connectors, making it a fairly simple process for two people to remove the wings in about half an hour for trailering.
The fin and tailplane are aluminium skin over riveted main spar and rib construction. The rudder and elevator employ the same D-box and rib construction as the wing. The elevator has a powerful electric trim tab, normally operated by two buttons on the stick, although they were located between the seats on the Mahonevs' aeroplane. Trim position is indicated by a LED indicator on tile panel. Pitch control is via bell cranks and push-pull rods supported bv rollers. Rudder pedals, hinged from the floor, are rod-linked to the nose strut, and by cables to the rudder. The ‘Y’-shaped stick provides separate grips for left and right seat, each also with a separate brake handle attached to the stick, providing non-differential braking to both main wheels. The parking brake valve is between the seats, all other controls and instruments are easily accessible to both pilots, an extra slip/ball is in front of the right-seat pilot. There's ample space for a conventional bat and ball, GPS, and any other trimmings you may desire.
Overall design and finish, including the engine installation, is highly professional. The 100bhp Rotax 912 ULS drives a Kiev 3-blade composite propeller through the standard 2.43:1 reduction gear box, and for super-economy where strip length isn't critical, a Rotax 912 of 80bhp is optional. There's about 23 cm (9") static prop clearance, and the proximity of the tip to the ruggedly-sprung nosewheel means you'd have to taxi over something like a high kerb to damage the prop through ground contact. This, coupled with the ability to get the nose up with elevator even while taxying, provides the rough field tolerance of a taildragger.
The upper half of the composite cowling can he released by turning just four Dzus fasteners, and even the bottom half can be removed by releasing four machine screws providing easy access for servicing. The largely transparent fuselage has a maintenance inspection aspect too - you can see a lot of what needs to be inspected without removing a single panel.
Climbing in and out of the Foxbat presents no problems, and once settled in there's absolutely no feeling of confinement. Seated comfort, control reach and forward vision through the huge curved windscreen are excellent, and cabin noise level is acceptable in all phases ot flight although good quality noise cancelling headsets are, as always, recommended.
Taxying is a breeze with the responsive nose wheel steering, effortlessly producing an inner-wheel turn radius of around 1.5 metres even though there's no independent braking, and the forward wing sweep helps you keep an eye on the wingtips for tight manoeuvring. The brakes are responsive, effective, smooth, and easy to operate, The highly responsive elevators make it easy to raise the nose while taxying, even at relatively low rpm, but care is needed if you don't want to be seen resting on the in-built tailwheel.
Microlight heritage
You're really reminded of the Foxbat's microlight heritage on your first take-off. The nosewheel can be held off the ground almost from the start of the take off roll, and acceleration is notably brisk. The slightest back-pressure on the slick has us airborne and climbing at such a startling angle that I double-check the ASI and we're indicating a healthy 50 kt, with ample response to fingertip-light control inputs. With 10" off flaperon extended 1 estimate we were airborne in less than 80 metres at maximum takeoff weight on what must have been close to a standard day, at 2,500 feet above sea level. That was a good start to convincing me that with a bit of practice on low-speed landings, Foxbat could be safely operated from a 200 metre ultralight strip with adequate safety margins. The 1,000 fpm-plus climb would certainly amaze any student pilot accustomed to the performance of some of the more popular two-seat VH- registered trainers, and just imagine how many more circuits and landings you could fit into an hour if you weren't queued up for a bitumen runway and an ATC clearance. As well, the confidence you'd rapidly gain in Foxbat's low speed handling capabilities, would soon enable you to practice 500' circuits, and I'd estimate a landing every three to four minutes would be easily achievable as you gained confidence. That's (say) 15 circuits an hour, compared with six if you're lucky at Bankstown or Moorabbin. Forward visibility in the climb can be improved by lowering the nose to a more realistic level without losing much rate of climb, and the all-round visibility provided by the transparent convex doors help us maintain good situational awareness as we explore Foxbat's low speed handling. We quickly find that controllability at a 40 to 45 kt trim speed is still of a high order, and let's not forget that even at 40 KIAS you have a 50% safety margin above the stall speed, an incredible 27 kt with full flap. A 30° to 30° roll takes two seconds at normal cruise, and 4.5 sec in approach configuration with full flaperons. Control inputs are still light, and Foxbat quickly convinces us of its utility in spotting and photographic roles. With the door carefully removed the field of vision is truly spectacular, with the wing strut well behind you so it doesn't tend get into the photograph.
Eighty-five to 90kts cruise with a fuel burn of around 14 litres/hour is a realistic continuous speed for this aeroplane, which however is more comfortable at around 75% power and 74 kt, where you'll achieve a fuel burn of about 10 Iph. If you're happy with 45 kt the handling is still perfectly comfortable, and the Foxbat's endurance would probably exceed your own.
Some nifty rearrangement has been done on the flight control, in response to criticism of earlier models' control harmonisation. Aileron, elevator and rudder inputs all have similar input weight at any speed in the operating range, which in all practicality starts at around 30 kt and goes right to never-exceed speed (Vne) of 110, which won't be achieved in level flight, where max is 105 kts. Best gliding speed appeared to be about 48 kt, producing a modest 350 fprn rate of descent, which is close to a 14:1 glide ratio - over 14 nm from 6,000 feet if you're ever faced with the necessity. And if gliding doesn't appeal, the aircraft can be fitted with a ballistic parachute to lower you gently to earth.
As you'd expect of an aircraft with these characteristics, stalling is an unexciting affair except perhaps at climb power with full flap, and you'd have to be a serious dunce to ever stall a Foxbat inadvertently. In level flapless flight, you have good three-axis control right down to the break at 32 kt, where mild aerodynamic buffet gives you plenty of warning, but in most configurations, the major symptom to watch out for is a high rate of descent, which is normally arrested simply by adding power. However, at steep nose angles with 20 degrees of flaperon you may also observe a tendency to drop a wing, which is negated by simply relieving back pressure on the stick. In that configuration, the stall break appears to occur at about 24 kt, although the advertised stall speed is 27 kt. Pitot position error at the unusually high angle of attack may account for that discrepancy. Stalling in turns, the Foxbat tends to roll to level flight rather than 'tucking under' as many aircraft will do.
Keeping you on your toes
Despite its low-speed capabilities, its huge - just 3 mm short of 10 metres - and its general configuration, the aircraft takes a little slowing down to maximum flap extension speed of 58 kt. The electric elevator trim is very effective down to all but the last 15 kt of the speed range, after which you need only relatively light pressure to hold the nose up, for example in a minimum speed approach for a super-short landing. It's quite an experience landing the Foxbat into a 15 kt wind, with a touchdown speed of 10 kt, but this should only be attempted when you're very comfortable with the aeroplane, and fully aware of any possible wind gradients close to the ground. A safe and non-frightening short field approach would be at 45 KIAS, reducing to 35 over the fence.
Controls remain effective and easy to manage in a sideslip or a crosswind landing, and with Foxbat’s low touchdown speeds there’s hardlya crosswind that will stop you, because you can always land into wind.
At (A) $77,500 including GST, shipping, and registration, a factory-built Foxbat makes a great touring aeroplane - versatile, comfortable, robust, economical, and really fun to fly. When you've refuelled, you'll want to get back in and do it again. And considering all the friendly little airfields this remarkable aeroplane opens up, you probably will.
with a slight tailwind. It's journeys like that, replacing more than eight hours of driving time, along with the modest price and low operating costs, iliat get you thinking about the practicality and utility of owning your own light sport aeroplane. Sales Manager Peter Harlow of SilverWing Aviation, thoroughly familiar with the aeroplane, took me flying in this remarkable little aeroplane.
One of th<e first things you notice about the Foxbat is that it's very transparent! Much of the fuselage that would normally be covered by conventional skin - including the lower half of the huge doors - is instead glazed with Lexan transparent material. The resulting all-round view from the cabin bubble is astounding, because vou can see where vou've been almost as well as vou can see where you're going, with helicopter-like vision - although there's a bit of a blind spot in a steep turn if you don't crane your neck forward and look up through the well-raked windscreen.