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FLY03_FlightTest(rev).PW.LeP 2/21/05 12:34 PM Page 4 mph. The advised climb speed of 100 mph yielded a climb rate of 3,400 fpm. I discovered immediately that this aircraft is very responsive to stick or rudder input. It took a bit of right rudder to keep the aircraft on heading during the climb out. Cruise speed is 200 mph and Va is 180 mph. According to the book, the Vne is 260 mph but during flight testing speeds of 330 mph have been reached without any flutter or other problems arising. On the way to our training area I checked some stability parameters (for the record, all speeds quoted are IAS, there was some turbulence about and we operated between 3,000 and 6,000 ft). Static longitudinal stability: from a trim speed of 200 mph I progressively reduced the speed through 10, 20 and 30 mph by pitch input. The force necessary to keep the aircraft 30 mph off the trim speed was in the order of 3 to 4 kg. The stick force gradient appears to be linear. I could not detect a real breakout force. Slowly allowing the stick to return to trim position and releasing it resulted in a sick-free return speed of 198 mph. A push force of about 2 to 3 kg was necessary to keep the aircraft 30 mph above the trim speed. This time the stick-free return speed was 200 mph. The same procedure was repeated at Vapp, 100 mph, and I found that the stick forces were approximately 1 to 2 kg at most – making the stick more of a pressure control than a movement control. Flying with the fingertips is the name of the game. MSW AVIATION VOTEC 322 �DIMENSIONS Wingspan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.30 m Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.50 m Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.50 m �WEIGHTS & LOADINGS Weight, empty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 kg MTOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 kg Max wing loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 kg/m 2 Max power loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.97 kg/PS �PERFORMANCE (at 950 kg) VNE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 mph Level cruising speed, 75% power . . . . . . . . . . . . . . . 218 mph Stalling speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 mph Max rate of climb, sea level . . . . . . . . . . . . . . . . . . . . . . . . . 3,000 fpm Takeoff run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 m Landing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 m Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,200 km g limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +/-10 Manufacturer: MSW Aviation, Rigackerstrasse 24, CH-5610 Wohlen, Switzerland. www.mswaviation.ch Base price (kit): 100,000 euros Dynamic longitudinal stability (long period): From a trim speed of 170 mph the speed was reduced by pitch change to 160 mph, the stick was moved to trim position and released. The ensuing phugoid was only lightly damped (meaning that the 322 has slightly positive dynamic longitudinal stability). The maximum speed was 185 and the minimum speed was150 mph. Short period: The frequency is pretty high and the moment you release the stick the oscillation stops, so the short period stability is deadbeat. Directional/lateral stability: at 200 mph the rudder was slowly moved to maximum deflection and with opposite aileron the heading was kept constant. The rudder forces increased steadily. Without specialist instrumentation, my best estimate of the rudder force was 25 to 30 kg at maximum deflection. The maximum yaw achieved was 30°. ‘Playing’ the stick with two fingers (minimum stick force/movement) was enough to keep the aircraft on the right track. Releasing the rudder caused the aircraft to yaw back nicely. No rudder lock was observed. Flat turn: at a trim speed of 180 mph turning the aircraft with rudder alone was possible. Again the necessary stick forces and the stick movement to keep the wings level were minimal. Dutch roll: pushing the rudder left and right produced only yaw. Release the rudder pressure smartly and the snaking motion will stop after three to four overshoots. With the stick free and slowly feeding in rudder it was not possible to pick up the wing from a 30° bank (left or right makes no difference). This behaviour is not really surprising since there is no dihedral built into the wings. Aerobatic pilots prefer this kind of neutral stability (not found in normal light aeroplanes) as they need not worry about inadvertently rolling when yawing. However, if you desire it, the aileron spades can be fine-tuned to reproduce the dihedral effect. (Actually, the <strong>Votec</strong> 322 was flown with this form of ‘dihedral’ at one stage, but the aerobatic pilots asked for the effect to be removed.) 322’s aerodynamic balance is tuned to perfection Manoeuvring Stability: during a ‘wind-up’ turn it was found that the stick forces increase with increasing g-load up to about 4g. I estimated the stick force to be some 1 to 1.5 kg per g. As I continued to pull more g, I had the impression that the stick started to move further back on its own. This reduced stick force also reduces pilot workload during high-g manoeuvres or high-speed manoeuvres. Again the stick displacement is minimal. For the manoeuvres flown, the stalllimited maximum g-load I achieved was +7. The seating position is very much like in a glider, with full leg support down to the ankles… You thus have what is effectively a g-suit - 6g felt more like 2g Throughout the flight test, I came to appreciate the excellent seat. The seating position is very much like in a glider, with full leg support right down to the ankles. Thus, upon pulling g, your legs will be squeezed against the supports and – voilà – you have what is effectively a g-suit. If you doubt that such a simple idea could work properly, or think that might pose other problems, all I can say is that I found that 6g felt more like 2g, and getting in and out of the aircraft is not a problem. The very comfortable seating position is also a huge benefit for your back (a babe in a cradle could hardly be happier). Sighting frame gives essential ‘lines’, elegant spat backplate features NACA brake cooling intake, vents ▲ MARCH 2005 FLYER 023 ▲
FLY03_FlightTest(rev).PW.LeP 2/21/05 12:34 PM Page 5 ▲ ▲ Little temptation for the aerobatic pilot to stay right way up, although straight-and-level range of 1,200 km on non-aerobatic max fuel is useful for transit Turn performance (maximum sustained g): checking the maximum sustained g is always a very tricky test, since you have to do a perfect horizontal turn with steadily increasing back pressure on the stick without climbing or descending a foot – which has to be done by adjusting the bank angle. If you climb, you reduce the available energy, and if you descend you add energy, thus increasing the apparent max sustained g. The maximum I could achieve in the above mentioned conditions was almost 4g. Spiral stability: with high directional stability and low lateral stability some sort of spiral instability was to be expected. Banking the aircraft to the left 20° and releasing the stick caused a slowly but steadily increasing left bank. So the spiral stability to the left was negative. To the right, the bank angle slowly but surely decreased indicating positive spiral stability. Trim: the trim system is an electrically operated Flettner type. It was easy to trim the stick forces to zero at cruise and approach speed. The only specific trim test I tried was simulating runaway trim at a cruise speed of 200 mph. The force necessary to keep the speed at 200 mph with trim fully forward was approximately 15 kg. With the trim fully back the force is approximately 10 kg. Power-off stall: the power-off, wings-level stall is a non-event. Stick back, the nose comes up, 3 to 5 mph before the stall (in our case it was slightly above 55 mph indicated – translated to max weight and ISA conditions, this gives a stall speed of 65 mph). A very distinct airframe buffet could be felt through the stick, the break was clean, the nose went down and a minimal wing-drop occurred. Moving the stick forward two centimetres re-attaches the airflow again, and the altitude loss until recovery is minimal (less than 40 ft). The ailerons remain effective without aileron reversal right into stall and even thereafter the fully-stalled aircraft can be turned left or right by the smooth (that is, not 024 FLYER MARCH 2005 excessive) application of either left or right stick. The power-off stall with 30° bank to the left or right is also a non-event, except that the speeds are a little higher. Accelerated power-off stall: first of all, the nose-up attitude is some 45° at the break. Speed just drops off the bottom of the scale, making it a bit difficult to judge the exact stall speed – but I estimated it to be approximately 30 mph. When the break occurs, the nose drops and yaws some 30° to the left, together with a wing drop of 15°. Power-on stall: the power-on (50 per cent MCP) stall wings-level is not a lot different from the power-off stall. Only the speeds are lower (30 to 35 mph), the nose-up attitude is more pronounced (around 60°) and everything is a bit more lively – but still easy to handle. With the huge power reserve this aircraft enjoys, one can also recover from a stall in a very different way. This is how it goes: slow the aircraft smoothly and steadily increase power. At the point the stick is fully aft and maximum power is reached, Slow the aircraft and steadily increase power. When the stick is fully aft and maximum power is reached, the 322 will hang suspended in time and motion the airspeed will have dropped to a very nice zero. The 322 will hang there, in a 60° nose-up attitude, seemingly suspended in time and motion. The minute corrections necessary to keep the aircraft hanging there have to be experienced to be believed – truly astonishing. When you move the stick just a hair forward, the aircraft launches forward and, in a heartbeat, you are at flying speed again. Count ‘one-and-two’, and you are travelling again at 180 mph… Accelerated power-on stalls with 30° bank to the left or right are very lively indeed, but still easy to handle. Spin: entry is standard and the break is very gentle. The turn rate (approximately three seconds per turn) and the nose-down attitude (approx 45°) are very comfortable. After one turn, neutralising the controls is enough to stop the spin. A slight pull is sufficient to pull out. Behaviour is the same, turning left or right. It takes three turns for the spin to become fully developed and stable. The altitude loss for a three-turn spin was some 600 ft. Inverted spins were not attempted but, according to Max, these are “no big deal”. Aileron roll: You have only to think ‘roll’ and the 322 rolls (indicating a roll-mode time constant of 0.00 seconds!). Shove the stick to the left or to the right (the throw is 18 cm) and the full-span ailerons will ensure that the whole world rotates around you at a tremendous speed. The roll rate of some 400 degrees per second demands some attention to arrest precisely but, with a little bit of practice, I managed to stop the roll as desired. The maximum stick force was approximately 2 kg at full deflection. No roll ‘ratcheting’ was observed. One would assume that this kind of roll rate should be enough even for the most demanding aerobatic pilot. However, Max would not be Max if he were not trying to make it faster still. Currently, he is experimenting with sealed ailerons and different sizes of spades. The sealed ailerons look very promising but the fine tuning is still in progress, so no official figures have yet been posted. What happens if you move the stick to the left and release the stick? The aircraft just keeps on rolling at a steadily decreasing rate. Flick roll: Maximum speed for a flick roll is 140 mph and the flick is initiated by a quick pull on the stick followed by hard application of left or right rudder. Once the aircraft rotates you increase the rate by unloading the elevator by easing the stick pull. Opposite rudder and a bit of forward stick arrest the flick. Vertical penetration: with an entry speed of 200 mph and a 4g pull up you run out of steam some 3,000 feet higher. Time ‘in the line’ is approximately 14 seconds. You want to roll on the way up? Four vertical rolls are not a problem and five can be achieved with finesse. The aircraft prefers to stall turn to the left. Loop: move the stick back a fraction (or, more accurately, simply apply back pressure) and you are inverted. Due to the amount of power available I ended up higher than expected, and I experienced airframe buffet when first pulling up into a loop. With such a powerful elevator it takes some practice to fly smoothly with minimal stick movement.
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