| AVIAZIONE LEGGERA ON LINE - IL GRANDE SITO DELL'AVIAZIONE SPORTIVA ITALIANA |
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It is really impressive as it whizzes by on a low pass over the runway, with its clean lines, almost difficult to follow with a camera, and it is just as impressive as it shoots up in the sky becoming a tiny dot before losing airspeed.
That's the Ban.Bi for you, an "inexpensive two-place fast cruising aircraft", as defined by its manufacturer.
Designed by Michel Colomban (who also built the tiny Cri Cri), it is built in the French workshops of Dyn Aero, the company owned by Colomban and Cristophe Robin, son of the legendary Pierre. The aircraft is entirely built out of composites and has an amazing tiny wing, just 6,6 metres in wingspan and less than 7 square metres of surface area (7,9 and 7,5 respectively in the ULM version), basically a wing loading of 65 kg per square metre! With such high wing loadings you have no option but to go fast and designers had to do wonders with the flaps (double slotted and blown). The aircraft comes in three versions, ULM, Club and VLA, in two-stage kits or ready-to-fly, at a competitive price when compared with available fast aircraft. The price is unbeatable when performance is your only concern. Needless to say, the utmost care was put into developing clean lines and sophisticated aerodynamics, even in hidden areas: the engine cowling is a masterpiece, with carefully designed air intakes and an internal vane system for separating cool inflowing air from hot, even though this required a complex cooling system with a manually operated electric fan used to dissipate heat after landing. With such flying characteristics, a variable pitch prop was a must: not just a fancy toy but truly an essential item. Inside the cockpitClimbing in is easy, you just have to put your feet on the front edge of the seat and slide down in what seems like a perfect body-wrapping cocoon (we flew without problems with neither cushions nor padding); the body position is quite good, the control stick is short and between the pilot's legs.
Flying the Ban.BiAre 80 hp enough? In this case they are more than required, and not only in flight. You can certainly agree that with three wheels on the ground and during initial acceleration the wing and aerodynamics matter very little. The Ban.Bi, with the three-blade variable-pitch Quinti Avio propeller, constantly reminds you that the available horsepower is always plenty, as long as you know how to use it up (so much for turbochargers!).The Ban.Bi shoots off the blocks like a real thoroughbred and in 9 seconds we are at rotation speed! You have to start fiddling with the flaps right away as things happen very fast in this plane, and as the runway becomes smaller and smaller behind us the air speed indicator shows 180 km/h in a steady climb. We level off with the engine at 4800 rpm, the noise level is low and uniform so much so that initially it is hard to detect rpm variations, unlike in slower planes, and often you can find yourself flying at 500 rpm more than required even if you use a light touch on the throttle. It is just a matter of getting used to it, although initially it is best to check instruments often. Now, then, let's take a look at what this "rocket" can do: first of all, it is a stable aircraft while being very responsive, offering the kind of precise flying you find in a Pitts Special, and with an incredible roll rate, one of the highest around. Consequently, you need very little stick effort to do turns, with no need at all to use the pedals. The Ban.Bi gets back and "locks" itself in straight and level flight as soon as you centre the stick…pure fun! As far as speed is concerned, you can cruise comfortably at 260 km/h with a low 9 litre/hour fuel consumption; basically, you put the throttle to the wall only for the thrill of seeing airspeed shoot up to 300 km/h, as with economy cruise you are already going places in half the time you deemed necessary, cutting up turbulence and ignoring frontal winds, even on long trips. Approach and landing definitely need a good deal of attention: flaperons are quite responsive on final and the "reduced" approach speed is good, although touch down is inevitably at a speed which is higher than your average light aircraft. Sure enough, 200 metre fields are no longer enough (the Ban.Bi, using the brakes as best as one can, stops in about 250 metres from point of touchdown) The Importance of the PropellerOur first flight of the Ban.Bi was with a three-blade Arplast propeller without automatic pitch control, forcing us to manually correct the pitch several times; performance was good at low and medium speeds with good acceleration in take off.A major improvement was given by installing an automatic pitch control Quinti Avio prop, which is set up according to the characteristics of each individual aircraft type and fine tuned following a precise set of in-flight measurements. At this point, the pilot only has to work on throttle settings knowing that he'll have the optimal pitch for every flight situation, every time. Consequently, you get a strong but very progressive acceleration on take off. After lift off, you retract the flaps and climb out at 160 km/h, and gradually up to 180 km/h with the pitch adjusting automatically without any vibration. Straight and level cruise is a blast, at an incredible speed of 270 km/h at a setting of 24 MAP and 4800 rpm. Increasing MAP to 25 the airspeed goes up to 280 km/h. The propeller works wonderfully, turning out to be quite suited for high speeds; particularly, you fell no vibration going from one setting to another, unlike the Arplast. The automatic pitch control unit allows for incredible performance: a cruise of 270 km/h at 4800 rpm and 25 MAP, an economy cruise of 250 km/h at 4500 and 22 MAP, and an incredible top speed of 300 km/h at 5000 rpm and 27 MAP. The preset maximum MAP setting is 29", therefore you would still have power left with the plane flying close to VNE; the propeller definitely proves itself to be quite efficient at high speeds. Not for All PilotsWe are planning a trip to France to try out the new four-seater and the ULM version with a stretched-out wing, downward winglets and a flaperon system which lowers stall speed to 63 km/h. Whichever way you look at it, the Ban.Bi is not really a plane for all pilots: it requires good flying skills and the ability to manage situations typical of more complex aircraft; those who will take a humble approach to this beauty will be rewarded with performance and control responsiveness which set a benchmark in this category. It is this standard of excellence that makes the price utterly competitive when compared to other top of the line ULMs and simply incomparable to that of certified aircraft with similar characteristics.Technical Specifications
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