French Kiss Frank Ogden The Kiss is a highly significant trike. Not only is it the first new design to reach the British market for several years, it is also the first kit-built flexwing to go through the BMAA airworthiness scheme. Frank Ogden assesses the French newcomer. BMAA member Steve Elsbury is building a Kiss 400 and has a web site for others interested to see how the build is going and to learn from his experience if they want to build one for themselves. This link, along with many others, has been available via the BMAA Directory for some time. Our list of microlight oriented links is updated regularly. At almost every microlight club meeting and trade event one attends, you hear the repeated refrain as to how British flexwing manufacturers are locked into a design time warp. This criticism is as unfair as it is regrettably true. Our Section S airworthiness system was forged at a time when one or two highly suspect three axis aircraft designs fell out of the sky very publicly. This resulted in a stifling UK regulatory approach that we still have to live with nearly 20 years on. The French in the mean time had no such inhibitions. Pilots could operate and fly weightlimited machines on the basis that, provided they killed only themselves and nobody else, then the Department of Aviation would take minimal interest. The French ULM manufacturers were allowed to accept responsibility for ensuring safe design: They simply reckoned that selling lethal machines was bad for business; proven design negligence could leave designers and manufacturers open to action in French civil courts. While this approach has had few implications for aircraft safety, it has given French makers greater scope for successful mutation of the basic microlight genre and a larger home market for economy of scale. Air Creation has been around since 1982 producing some 4000 wings and 2500 trikes since it began. Based at Aubenas in Southern France it currently employs 27 people turning out new machines at the rate of five per week. This productivity is at least double that of any company in the UK. The Kiss 400 weightshift microlight is a typical result of the pilot-focused, free-wheeling design philosophy allowed by the French certification system to which UK importers Flylight Airsports, run by Paul Dewhurst and Ben 'Doodlebug' Ashman, have added the probity of full UK BCAR Section S certification. UK pilots can now buy and fly a genuinely different - and possibly more advanced - flexwing aircraft... providing they don't mind building it first. More about this later. First impressions count and they are all good. Even the leaden skies of a bleak Northampton November afternoon couldn't disguise the bright plumage of a small, complex but beautifully cut wing sitting on top of an equally colourful metal and plastic trike. And the wing is small: just 13 sq m of composite fabric lifts 400kg of man and machine in dazzling style. At over 30kg/sq, the effective wing loading of the Kiss 400 blows away the old 25kg/sq m Section S definition of a microlight; it follows the new rules governed by stall speed. The low speed characteristics of this two-seater pocket handkerchief were likely to be interesting. The other aspect which immediately impresses is the short wing keel. It is indeed so short that the extended propeller arc misses the keel and trailing edge of the wing except for the final metre or so at each wing tip. This allows the propeller to throw stones, cameras and lose items of pilot/passenger equipment harmlessly upwards without slicing through a critical part of the wing. If it were not for two seats and a meaty Rotax 582 high power engine behind, a casual glance might mistake the machine for a Chaser S. There are other touches to delight pilots like me who enjoy chucking a tent and sleeping bag in the back of a trike to go touring for a few days. When not occupied by the rear passenger, a U-frame folds up from within the seat area behind the pilot to create simultaneously a comfortable back rest and a usefully large zippable luggage bag. The other delight is the optional 60 litre fuel tank (as fitted to the review machine; standard fitment 38 litres) which will tilt the balance of flight endurance towards the pilot's need to jettison previously drunk cups of tea rather than the machine's need to take on more petrol. There is a serious point about fuel and cockpit loads which applies not only to the review machine, but any fitted with tanks larger than the 50 litre maximum allowed under the old regulations. Some voices will raise objection that the fitting of big tanks as standard encourages people to fly overloaded machines. Using the example of the Kiss 400, a combined pilot and passenger weight of 180kg leaves an allowable fuel volume of just 27 litres without exceeding the 400kg MTOW limit. The doubters say that pilots will inevitably fly two-up and fuelled over the weight limit. I would answer that decisions on cockpit load/fuel weight trade-offs affect every branch of aviation and there is no reason as to why microlights should be made a special case for concern. I personally do most of my flying one-up and all the more safely for having a purpose-designed single tank of adequate capacity. Complicated multi-tank fuel arrangements have caused serious problems for pilots in the past and it is my view - offered with the benefit of 17 years experience flying flexwing microlights - that the new regulations take flight safety forwards, not backwards. We are quite aware that overloading is neither safe or sensible: heavy loads adversely affect takeoff roll/climbout, particularly on soft grass strips, and primary flight characteristics especially in parts of the envelope towards the stall. The Trike The first - and lasting - impression is of design excellence. The beautifully moulded fairings partially conceal a fairly simple tube and bolt structure in which the individual tube members have been factory finished in a hard coat paint to match the mouldings. The single drum brake arrangement on the sprung front wheel is the same adaption from a motor scooter as currently fitted to Pegasus trikes. The unbraked rear wheels inside finned spats - these assist lateral flight stability as well as keeping flying stones away - are triangulated at the bottom of oleo suspension struts. They subsequently proved themselves to be soft enough to adsorb the bumps of taxiing without the rest of the machine wallowing around on over-soft suspension. The main wing pylon folds forward for (de)rigging, hinged at the top of the seat frame in the style of Pegasus Quasar trikes. This vastly improves design ergonomics over folding trike arrangements. It allows installation of large, permanently installed fuel tanks, a favourable trade between structural strength and weight and gets rid off that cow poo-collecting fabric 'skirt' at the rear of the pod which make old British trikes look so shabby. The front forks with the oleo-damped wheel assembly turn in what amounts to a large hole in the bottom of the pod - no draught excluders here! However, a moulded fairing around the hole really does stop the wind blowing around up your ankles in flight. Paul Dewhurst said it would and it does! The trike has other, finer design touches. The starting battery (electric starting for the 582 is listed as an optional extra which, in my opinion, amounts to a screaming necessity) fits within a recess at the bottom of the HDPE plastic fuel tank moulding with the trike keel taking the weight of the battery. The three-point engine mounting virtually eliminates perceived vibration from the watercooled engine. The unit is mounted at a slight slant along its axis to offset the propeller torque reaction on the mounting rubbers by virtue of its own weight. The notable lack of in-flight vibration is also probably helped by the slow-turning three-blade propeller driven through the 3.47:1 reduction ratio E-series gearbox. It makes the aircraft remarkably quiet when witnessed either from the ground or from the pilot's seat. The cooling system also has a nice touch: the radiator is mounted horizontally below the trike within a moulded cowling, forcing air downwards through the matrix. Wire mesh keeps out the crap. Cockpit instruments are mounted into a fairly small front panel with little room for more than the basic flight and engine necessities. But this is very much part of the machine's Gallic heritage. The French really do think that British trike flyers are a bunch of fairies for wanting any kind of weather protection, never mind instrumentation… Sizewise, cockpit accommodation is definitely on the cosy side when flying two-up but near perfection when flown solo. The pilot leg room suits me perfectly but then at 5ft 9in I'm not much of a design challenge. However, with Paul Dewhurst in the rear seat, I think that we both experienced a degree of intimacy unusual outside the realm of consenting males. At 6ft 2in and 95kg, Paul is definitely not built to Section S. The wing Apart from being visibly small for a two seater machine, the wing planform looks in no way unusual. But then, as with so many aspects of this French machine, interest is in the detail. For a start the principal sail surfaces includes Dyneema filaments within the weave creating a material of much greater intrinsic strength than that of pure Dacron. Dyneema is a proprietary high performance polymer made by the Dutch chemical giant DSM and enjoys similar tensile characteristics to Kevlar. Leading and trailing edges are reinforced with a laminate for architectural stiffness. The sail retains a beautiful cut both on the ground and in the air without any sign of wrinkling or, Heaven forbid, flapping. The undersurface occupies some 80% of sail area and connects to the upper surface by a flexible neoprene tie strip along its entire trailing edge allowing a degree of relative movement between the upper and lower surfaces for controlled aerolasticity. A further tie system between upper and lower surfaces is located deep inside the wing chord close to the leading edge. This arrangement gives a positive servo assistance to roll inputs making the machine demonstrably light to handle in the air. Air Creation has provided a neat finishing touch at the wing tips with caps between upper and lower wing surfaces held in place by Velcro fastenings. 23 top surface and 12 undersurface batons maintain the wing profile. The batons are retained in their pockets by ordinary cord rather than the ubiquitous bungee. According to Dewhurst, the dimensional stability of the sail material obviates the need for a flexible baton retention system. Certainly the machine flies straight as a die in the air. Should a turn ever manifest itself, it can be tuned out by rotation of the sail attachments at the wing tips. Structurally speaking, the wing holds no surprises. Interest is once more in the detail. For instance you won't find a bolt through a bit of ali channel hinging the crosstubes to the leading edges. This French machine uses a purpose designed complex hinge giving a controlled movement in three axes. The hinge components are individually machined from solid metal. Having said this, I rather like the simplicity of a simple aircraft quality bolt at this lifedetermining position. The trim system shows the same attention to quality and detail. The trim knob on the A-frame uses integral gearing to ease use in the air while wearing thick gloves. The system acts on the middle luff lines only but this is sufficient to take 10mph off the 60mph untrimmed airspeed. The airframe uprights have been faired with clip-on profiled coverings offering a neat, structurally neutral solution to draggy tubes. Some enterprising chap should offer them for sale to those of us with older trikes: I am sure that there would be quite a few buyers for such a simple solution to an old problem. In Flight With Paul Dewhurst shoe-horned into the back seat we commenced taxiing to the easterly holding point at Sywell. The massive foot-shaped pedals for brake and throttle are also the footrests and operating them smoothly does take a bit of practice. Ground steering is satisfactory - very little wallowing on the suspension - although the drum brake on the front wheel is not progressive and tends to snatch. Lined up and cleared by the Tower, the excitement begins. The first thing you notice on opening the throttle fully is how leisurely the 582 sounds. Although it pulls 6200rpm, the big reduction on the slow-turning prop made me wonder if I had opened the throttle fully. The next 100 metres of travel down the slightly bumpy grass strip dispels any doubt with the machine rotating decisively at just over 40mph IAS. You know instantly that the machine is a good one. It leaps into the air in an absolutely straight line and the pilot becomes immediately aware of the positive forward bar pressure required to keep airspeed down to 50mph for best climb performance. And what performance! The Kiss had no trouble sustaining a timed 700fpm at the maximum legal takeoff weight of 400kg. Indeed, it mostly pushed 800fpm fully laden. And it wasn't the sort climb rate that required a bit of nudging and scratching around the heavens together with a scrupulous eye on airspeed to maintain. The machine achieved this climb effortlessly and repeatably. I couldn't wait to get the thing back on the ground to boot Paul out and see what a French Kiss could really do. Also, I found that his long legs were projecting so far forward past my shoulders that I couldn't really pull the bar in far enough for fun without giving him a kneecap job. Before this, there were other things which this machine absolutely begged you to try. Blade and Q(uantum) pilots would be totally familiar with the fully laden pitch response of the Kiss reassuringly positive and disappointingly heavy. It needs real muscle either to hold the bar into your chest or outwards against the front strut. Heaving the bar in returned a sustained IAS of 85mph while straining to keep the bar against the front strut brought the indicated airspeed down to 40mph without any sign of an imminent stall - both figures obtained at 400kg flying weight. The engine seemed fairly leisurely in the cruise. With the trim control set at fast giving a handoff indicated airspeed of 60mph, the rev counter showed 5000rpm. I would guess - and it is only a guess - that the power setting would equate to about 12-14 litres/hour. Winding up the trim control took about 10mph off the airspeed but I can't imagine why anyone would really want to do this in a machine built for going places. Opening the throttle on most machines while straight and level normally produces a climb with little change in indicated airspeed. The Kiss is unusual. Opening up the throttle puts about 10mph on the airspeed and requires a pilot input to convert all the added power into climb. This isn't a problem, just a noticeable difference. The roll response is probably the lightest that I have ever come across in a two seater flown two-up. It acts both rapidly and positively and probably requires about half the effort required for Blades and Qs. This French machine is possibly even lighter in roll than my own personal two-seater favourite, the Raven. It is quite a good test of roll control to place the machine in a gentle bank and take your hands off the bar. Well-tuned Pegasus wings will eventually reduce the angle of bank without pilot input. Ravens have a tendency to increase the angle of bank until things get scary. This French machine simply sits in the attitude you left it in although, like all flexwings, it requires a handful of opposite control to damp violent roll manoeuvres. There isn't a two-up stall as such. Gently decreasing airspeed by edging the bar up to the front strut simply results in a fully flying machine with ponderous roll response either in bank or level flight. Accelerated entry to the stall does produce a more classic response - a significant symmetrical drop below the horizon which can easily be recovered with carefully controlled rearwards bar movement. Interestingly, an observer in an accompanying chase plane said afterwards that the accelerated stall had looked spectacular 'losing several hundred feet'. I have to say that the manoeuvre did not feel spectacular from the pilot's seat; the positive and progressive pitch response of the Kiss 400 made recovery almost pedestrian. Time to head back to the airfield. The machine was easy to line up for a deliberately long approach: with an examiner of instructors and an exemplary pilot sitting in the back seat, I wanted to do the perfect landing. It wasn't to be. Executing a near perfect approach and sliding down to the threshold as if on rails with 65mph of airspeed on the clock, it looked as though the landing might be a greaser. Enter into the flare and burn off the flying speed at just an inch or two above the grass. All is going well until… you reach the front strut and the wretched machine is still flying with no forward bar movement left to flare with! The back gear gently touches the grass, hits the smallest of bumps, and sends you back a few inches into the air until the wheels touch the next bump. And the next… It was a perfectly acceptable landing but not completely tidy: the front strut places a restriction on forwards bar movement preventing the aircraft from flying right to the stall. This was borne out both by the stalling tests and in a further landing. Time to go solo with just 300kg of takeoff weight. With such a small, short keeled wing above, it is like climbing into a Chaser. Line up, open the throttle and... Wow! The high power 582 literally catapults you into the air after what seems like no ground run at all. The VSI edges past 1200 fpm and the thin layer of stratocumulus rushes down to meet you in a manner unusual for a microlight. Actually, the machine is climbing at such a wonderfully crazy angle that sky is really all you see, even with 50mph on the ASI. Oops. Extract myself from the cloud and try to be a tiny bit professional. Flown one-up the machine feels entirely different. True, it exhibits the climb performance of a sky rocket but what really stand out are changes in roll and pitch. Although both axes remain positive and convergent, they reduce significantly to the point where, if you were to shut your eyes, you could be flying a hot single-seater. You can throw the machine about, point it at any place in the sky or on the ground and go there directly and precisely. Wonderful stuff. This machine really does become a weightshift fighter aircraft. A more measured appraisal suggests a neutral bar trim of 58mph with the engine turning at 4700rpm for level flight - a fast solo cruise would probably be possible with a fuel consumption in the region of 10 litres/hour giving an easy endurance of 300 miles on that big 60 litre tank. Pass me the Little John. Pulling the bar right in puts 75mph on the ASI with the machine still capable of going upwards but the rearwards bar force required to sustain this would soon become uncomfortable. Pushing the bar gently out to the front strut once again fails to stall this machine. It simply grumbles along at 40mph or thereabouts. An accelerated stall entry once again produces a definite but easily recovered stall. The lowest sink rate on a trailing throttle would be about 500fpm at 45mph. And back for a solo landing. Once again, everything travels down on rails to the runway threshold resulting in a textbook flare. And once again, I run out of forward bar movement before flying speed has properly decayed resulting in a bump, bump, bump. Would I want to buy one? Oh yes, even if it is a bit of pain to put back on the ground cleanly. The Kiss 400 really does have a dual personality. As a small two-seater it outhandles the competition in most respects - it would have been interesting to fly this machine in heavy turbulence. The high wing loading might confer some advantage, possibly offset by the light roll characteristics. As a single seater hot ship, it wipes the floor with everything else that I have ever flown. This really is a machine that is whatever you want it to be. Get Your Kit Built Flylight only supplies the Air Creation Kiss 400 as a kit requiring typically about 100 hours of build time. The machine arrives in five boxes of various sizes containing absolutely everything needed for a complete machine. All the members are pre-cut and drilled and individually labelled. In essence, putting a Kiss 400 together is a straight Meccano job. The only drilling required is for a set of self-tap screws to attach the seat webbing. Construction has to be overseen through the BMAA inspector network with inspections taking place at rolling chassis, wing/airframe completion and after final assembly. TECHNICAL DATA Flylight Kiss 400 582 MANUFACTURER Air Création, Aérodrome de Lanas, 07200 Aubenas, France; tel +33 47593 6666; fax +33 47535 0403;. Director: Jean-Luc Tilloy. IMPORTER Flylight Airsports, Sywell Aerodrome, Northampton NN6 0BT; tel 01604 494459; fax 01604 495007. Proprietors: Paul Dewhurst, Ben Ashman. SUMMARY Tandem two seat flexwing aircraft with weight-shift control. Rogallo wing with neither fin nor keel pocket. Pilot suspended below wing in trike unit, using bar to control pitch and roll/yaw by altering relative positions of trike unit and wing. Wing braced from above by kingpost and cables, from below by cables; floating cross-tube construction with 80% double-surface enclosing cross-tube; 22 battens on top surface, 14 battens on under-surface. Undercarriage has three wheels in tricycle formation; gas damped shock absorber suspension on all three wheels. Push-right go-left nosewheel steering independent from aero-dynamic controls. Drum brake on nosewheel. Rectangular-section aluminium-alloy tube trike unit, with glassfibre pod. Engine mounted below wing, driving pusher propeller. EXTERNAL DIMENSIONS & AREAS Length overall (to tips) 3.90m, 12.8ft. Height overall 3.57m, 11.7ft. Wing span 10.20m, 33.5ft. Chord at root NA. Chord at tip NA. Dihedral NA. Nose angle 130°. Wing area 13.3m 2 , 143ft 2 . Aspect ratio 7.5/1. Wheel track 1.63m, 5.3ft. Wheelbase 1.60m, 5.2ft. Main wheels dia overall 36cm, 14 in. Nosewheel dia overall 36cm, 14 in. POWER PLANT Rotax 582 DCDI engine, liquid-cooled. Max power 64hp at 6500rpm. Propeller diameter and pitch 1.70m x 23°@50.5cm radius, 67 inch x 23°@20 inch radius. Gearbox reduction, ratio 3.47/1. Max static thrust NA. Power per unit area 4.8hp/m 2 , 0.45hp/ft 2 . Fuel capacity 38 (60 optional) litre. WEIGHTS & LOADINGS Empty weight 178kg. Max take-off weight 400kg. Payload 222kg. Max wing loading 30.1kg/m 2 . Max power loading 6.25kg/hp. Load factors +4, -2 recommended, +6, -3 ultimate. PERFORMANCE* Max level speed 78mph. Never exceed speed 87mph. Economic cruising speed 60mph. Stall speed 37mph. Max climb rate at sea level 750ft/ min. Min sink rate 500ft/min at 45mph. Best glide ratio with power off 8/1 at 45mph. Take-off distance to clear 15m obstacle 159m on grass. Landing distance to clear 15m obstacle 180m on grass. Service ceiling NA. Range at average cruising speed 200miles with reserves and 60 litre tank. Noise level 80dB(A) LEL. * Under the following test conditions Airfield altitude 0ft. Ground temperature 15°C. Ground pressure 1013mB. Ground windspeed 0mph. Test payload 400kg. PRICE INCLUDING VAT £11750 +options and instruments NA = Not available Figures above are manufacturer's/importer's data Figures in text are tester's experience: test conducted 16/11/01 at Sywell Aerodrome, weather light overcast, stratocumulus, nil turbulence, <5mph surface wind, 11°C, QFE 1021mb, RH 70% (estimate).
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