The windsock hangs limp under a spring skyscape of decaying cumulus. I hoist the Java 155 to my shoulders and practice the deft one-handed movement required to push the throttle fully open. Lowering the glider to the ground again, I go through the starting routine: decompressor cocked, ignition on, 'Clear Prop!' and pull. An urgent thrumming comes to me from behind, and out of the corner of my eye I catch sight of the dayglo-tipped propeller slowly revolving as I blip the motor to warm it up. Picking the glider up again, I brace my feet against the anticipated thrust, dab a hand quickly down to the throttle and grab the upright again. As the motor picks up to an insistent but muffled roar I begin to walk, then run, ever faster, across the expanse of flat grassland ahead. After twenty yards I'm running on air! The nose pitches up a little and I'm climbing away, straight ahead, clawing for altitude in the afternoon sun. I'm alone in the sky on a hang glider and I'm going up - in a straight line!
The remarkable device I'm privileged to be flying is the Mosquito powered harness, imported from Sweden by Andy Buchan of Light Flight, on this occasion hung beneath Avian's viceless Java wing. One or two early Mosquito harnesses have been around in the UK for several years, scaring their pilots half to death with their marginal climbing abilities, but the latest - and now legal - model that Andy is importing has power to spare.
The heart of the device is a 120cc Husqvarna engine, tuned to go-kart power levels as the Radne Raket (rocket!) and giving 15 horsepower at 8,800rpm. The motor is permanently mounted at the back of an otherwise fairly ordinary pod harness and drives the two-blade carbon/kevlar pusher propeller via a toothed belt, centrifugal (i.e. moped-type) clutch and a long tubular shaft. The prop sits a foot or two clear of the end of the harness, protected from ground contact by two folding legs that retract to the horizontal when the harness zip is closed. The throttle lever is at the pilot's waist on the left, the choke, decompressor control and ignition switch are on the right and a small fuel tank lives high up on the right-hand upright. It's that simple.
Glider modifications are minimal. The keel needs to be shortened by a metre or so, then sleeved and fitted with a pop-button catch so the cut-off section can be replaced for ordinary flying. Wheels need to be fitted to the base-bar and cord loops attached to the lower side-wire tangs at the cross-tube junctions to attach the limit-stop ropes (these prevent the prop chewing up the glider's sail if the harness is swung too far out of line).
Is it easy to fly?
In a word, yes! I started the day at Andy's base carefully following the BHPA pilot-conversion syllabus: being introduced to the mysteries of power application, effects of controls and engine failure drills. The conversion course, which normally takes a whole day, usually includes a flight in a flex-wing microlight to demonstrate the effects of power on a hang glider wing. This was waived in my case due to my existing microlight time, and we moved on to safe climbing attitudes, turns under power and the importance of keeping the thrust line parallel to the glider's keel. Andy had some neat little instructional models that were useful in demonstrating the basic principles and by the time we set off for the flying field I felt fairly confident that I understood what was involved in flying the Mosquito.
Rigging and preparation
The simplicity of the Mosquito system became apparent when we reached the field. After rigging, the Java and tethering the nose to a ground anchor, Andy unzipped the harness bag, inspected the motor and hung it on the wing. Just like that! All that's required is to hook the harness on to the glider's karabiner, mount the tank on an upright, connect the fuel line and hook up the two limit-stop ropes to the loops protruding from the undersurface. The propeller is then secured to the shaft with a simple locking pin and the whole assembly is ready to be pre-flighted. From unzipping the harness bag to ready-to-go takes about five minutes!
Climbing aboard and starting up
This is where the Mosquito becomes a little bit awkward. The harness remains attached to the glider, so the pilot has to wriggle into the top-loading pod from in front, aided by a helper lowering the nose to the ground. Andy says the job can be done single handed, but it doesn't look easy. Once settled through the leg loops and various straps you feel a bit vulnerable. The weight of the engine rests on the two legs behind you, but they prevent you from walking backwards or turning sharply on the ground. However, as all you actually need to do is start up, pick the glider up, open the throttle and launch, it's probably not such a great handicap. I had watched Andy demonstrate a couple of launches and landings before I flew and the engine was quite warm, but if it's stone cold it's a good idea to run it up before you climb in.
Once I was settled in the harness Andy gave me a further briefing on launching, flying and landing characteristics, and a quick practice session on opening the throttle without losing ; control of the glider. Ground runs with a dead engine are also part of the conversion syllabus to ensure the student has grasped the correct glider attitude for launching. aerotow experience is definitely an asset here as the launch sequence is very similar - but not as brutal as being dragged off the ground behind a 50-horse Rotax.
In the air
With mounting apprehension I stood facing the zephyr of wind that was available. My mind was trying to remember climbing airspeeds and Andy's admonitions to 'watch it in the turns at first' and, 'remember the bar comes back further than you'd expect'. The wind-up I always experience on flying a new wing, plus the limp windsock, weren't adding to my sense of inner calm. Still, it was a big field, and I can run!
In more-than-gentle turns under power I found the glider wanted to wind-in quite strongly. Although Andy had warned me against feet-first steering - it gives an into-turn yawing component that is really unhelpful - I suspect that I was still doing this and making the spiral instability much worse. Keeping the climbing turns quite gentle avoided this problem, but I expect that with more time to tune in to the glider's characteristics under power steeper turns could be sustained.
At about 350ft I retarded the throttle to give a more gentle (and quieter) cruise-climb. In this condition the power-on characteristics were lessened and the machine became a joy to tootle around the sky. In the air my mental state is closely bound up with whether things on the ground are getting bigger or smaller, and the receding landscape made me really start to enjoy the proceedings. A certain amount of low-frequency vibration reached me from behind - the prop rather than the engine, I imagine - but the noise level was really the only negative sensation in an otherwise pleasant and novel experience. Here I was, ascending rapidly into the blue heavens without having to worry about keeping station on the tug or centering in the lift. A bit like the flying dreams I used to have before I started hang gliding!
Closing the throttle completely put me back on familiar territory - flying a good handling, high-performance hang glider. Apart from the put-put-put of the idling motor and the rearward bar position caused by the tail-heavy harness, I could have been out on my own wing after an aerotow release. Beep-beep-beep... What's this? As if on cue, a gentle blob of late afternoon buoyancy drifted up, giving me a chance to do a couple of 360s and gain fifty feet. No trouble here - it thermals just like any other kite - so clearly the idea of Mosquito- launched thermal flying is a practical proposition. Although I didn't stop and restart the engine in flight, Andy says that this presents no difficulty - and is essential for cross-country flight.
Down to earth
After a couple more sustained power climbs to lengthen the flight and observe again the transition from climbing to level flight and then gliding, I closed the throttle one last time and sank back to the lengthening shadows on the ground. I switched the engine off at about 300ft, confident that I could make the landing area, and coasted in. Putting my legs down early, and mindful of the deceptive bar-in trim position, I flew a completely normal hang glider approach. Andy had warned me not to do a big stand-up flare (propellers are expensive!) and that the trailing legs touch down before the pilot, so I cruised across the grass to a dead stop with just a steadily increasing push on the uprights. In any case the shoulders-forward trim position gives increased pitch authority for landing. Perhaps because my legs are longer than Andy's I didn't get the height cue from the trailing legs, but it proved to be unnecessary. My overwhelming thought was: can I have another go?
The verdict?
Simply brilliant! I can't afford a Mosquito, but if I could I'd seriously consider buying one. Not to give up 'conventional' flying but as another interesting way of getting 'up amongst it'. Andy says that group ownership is probably the way many pilots will go, and of the ten units he has sold already at least one is to a partnership. His customers are mostly people who have been flying for years; some have tried powered flying and not found it to their taste but all have a need for a more convenient form of hang gliding in the face of increasing family and work commitments.
Learning to fly it effectively will obviously take a while - Andy himself says he's still getting the hang of it - but its simplicity and the the fact that as a glider the outfit is no different from any other is a big advantage. The rather awkward technique required to get into the harness is a small drawback and the noise level in the air a greater one, although ear plugs are probably the answer to that. In answer to the obvious question, no, it's not noisy from the ground; at 300ft the Mosquito couldn't be heard above the sound of a nearby tractor and the little RAF training aircraft that always seemed to be buzzing around; overhead at 500ft it was close to inaudible.
Andy has used the Mosquito with gliders as diverse as the Solar Wings Typhoon, Rumour, Scandal and Breeze, the Aeros Target, the Airwave K3 and K4 and, of course, the Java (the Mosquito is not compatible with Airwave's Calypso). Apparently the higher performance wings are just as easy to fly with the Mosquito as the intermediates or older models.
The power harness is easy to convert on to for a reasonably experienced hang glider pilot (Andy recommends around 50 hours as a minimum). It's well thought out and put together and only hampered by the noise level for the pilot and the desirability for a helper on the ground. It's cheaper than most paramotor units and considerably cheaper than the only other hang glider power-pack on the UK scene. And the first Mosquito that appeared in the UK is still going strong after six or seven years!
The Mosquito harness will not appeal to the purist. Those who like novelty and those needing a convenient way to get airborne (no long drives, no winch queues, no aerotow crews - or fees!, no frustration) may be intrigued by the possibilities it offers. Soon someone will fly a long way in thermic conditions on one of these from a field not far from their home. Though many die-hards will scream that it's cheating, this onlooker at least will be very impressed.