Taking off with the Mosquito NRG

Your aim is to run very fast while you are buckled in equipment that weighs 60 or 70 kg (motor + wing). In other words you are doing something that sounds impossible. But it is quite easy actually: you let the machines do the hard work!!!

In more detail: Your objective is to run very fast without any muscle effort. You want to let the wing take a large percentage of your weight early on during the running and let the engine push you foward. The only thing you will need to do from that point onwards is move your legs and keep the wing in balance (both in pitch and roll) while you accelerate. At some point you will be running so fast that the wing will lift you by itself...

The following tutorial is aimed to help anybody who is new to FLPHG and chooses to fly during calm, turbulence-free periods of the day. It provides guidelines for excecuting an easy and safe take off in light, steady headwind on a large field with no obstructions.

Here is the procedure step-by-step:

- You throttle up the engine until it starts pushing you and you start running and pulling the wing with the hangstrap (not carrying the wing foward with your arms). That means that you start running with the engine at around 50% of power and letting the wing rise up and start flying. Remember that you are pulling the wing with the hangstrap and once it is flying you relax your grip on the uprights because you do not have to carry its weight anymore. Instead you start flying it.

- Once the wing has taken its own weight and is flying, you change grip on the uprights and you make sure you are relaxed in the arms, hands, fingers and not holdning tight. You need a light relaxed grip on the uprights in order to give the wing the opportunity to rise and tension the hang strap while at the same time your hands remain at the correct height (a bit below your chest). As soon as you establish a balanced flying wing then you are ready to increase your running speed even more.

- You continue accelerating and let the wing carry some of your own weight as well (let us say around 40-50% of your weight). As soon as the wing takes some of your own weight, you start feeling much lighter and are able to do the "moonwalk". When you do the moonwalk, you feel like you weigh very little and you are about to lift. But in reality you will be able to lower the nose a bit and retain that feeling of being very light while you continue running & accelarating without lifting off the ground. Remember that you need to have a light grip on the uprights, at this point it is even more important to be able to "feel" with your hands what is going on. You are by this point essentially flying - but you are still in contact with the ground. That mens that your weight has to be lifted by your leg straps, not by you hanging from the A-frame like a gorilla.

The more you accelerate, the more you will have to lower the nose of your wing in order to keep yourself from lifting off the ground. If you maintain a fine balance by progressively lowering the angle of attack while you accelerate (you gradually lower the pitch so that the wing is constantly carrying around 50-60% of your weight throughout the acceleration) then you will be able to run very fast without actually putting any muscle effort into it. You will, in other words, start moonwalking from early on and will continue moonwalking and accelerating even after you have opened up the throttle to 100% and gotten full thrust from the engine. You are basically going from a moonwalk with the engine spinning below full power to a moonwalk with the engine spinning at full power.
It is important to understand that once you close your teeth on that mouth gas and go to full power you are not going to take off immediately.... You will merely moonwalk and accelerate even more until the wing lifts you at a high speed and engine running at maximum rpm.
Remember that if you lower the pitch too much then you will feel that you are heavy and each step will feel like a heavy thumb on the ground. You may even get a feeling that the wing is starting to fly faster than you can run and you are unable to keep up with it - in that case you allow the nose to rise a bit and return to the moonwalking. The running is always done with a straight back and the hands on the uprights - not the speedbar.

Once again: The running will be done with a straight spine, grip on uprights below chest height, the chin up and eyes looking towards the horizon and with the push of the engine to the hips and/or a bit above. Do not run leaning foward and through the uprights like a free-flight launch from a mountain!!!

As soon as you are in the air, you have to change from upright position to prone. With the mosquito NRG it can only be done once you have changed your grip from the uprights to the speedbar. Only once you have both hands on the speedbar can you get your feet in the harness. Once prone, pull the nose down so that you are climbing with speed 10-20 km/h faster than your glider's trim speed.
The change from uprights to speedbar should be done only when you are 100% certain that the running is over, the wing is climbing and there is no chance that you will come in contact with the ground again and run any more. It is recommended that you change from upright position to prone as soon as you are in the air and climbing, it will help you gain full control authority over the wing and the harness. Upon changing you will need to pull the speedbar in and accelerate for 3-4 seconds (you may find yourself flying parallel to the ground during that phase) and then slowly release pressure a bit so that you establish a climb with good speed margins. The best climb rate is normally achieved with a bit of speeding, maybe 10-25 km/h faster than your wing's trim speed. The safest way to climb after take off is therefore in prone position, flying faster than trim speed and with wings level. Take off is easier and safer with VG at fully loose positing. Please note:

* Making turns under full power near the ground should be avoided as the torque of the engine may cause the angle of the turn to increase.
* Just like with any other form of flying, the take off with Mosquito NRG requires that both hands are on the control frame when you are lifting and climbing. If you experience any problem with you equipment you have to continue flying the wing regardless. If, for example, the mouth gas slips out of place then you have to try to spit it out and make a landing (rather than taking a hand off the control frame and trying to put it back in place).

CAUTION: The technique shown on the video (excessive speeding after take off followed by quick release of the speedbar) is not recommended for pilots new to the Mosquito and should definately not be attempted by beginners.

What can go wrong?

The technique itself is easy and guarantees good take offs. But a lot of guys make the mistake of trying to launch with a motor harness by doing it the way they would normally perform a free-flight take off from a mountain.
But taking off from a flat field under power is totally different from a hill launch. If you apply the same mountain launch technique on flat ground you will end up pushing out the nose far too early. Unfortunatelly this happens quite often. In other words it is the instinct/habit that takes over and makes people stall the glider during take off.

If you have taken off from a mountain many times then you have built an instinct/habit/muscle memory and become accustomed to running a relatively short distance, reaching your maximum speed within a second or two (with the help of muscle power & gravity) and then letting the nose come up and lifting you while the mountain drops away. Even take offs with ground towing go fast and usually require just a few meters of running.
When you start from flat ground (with engine power) you will have to run a much longer distance and come up to a much higher ground speed while the acceleration will take a much longer time, maybe 10 or 15 seconds. These extra seconds will feel like eternity.

These differences often cause mountain flyers to think that "this running should be enough" or "I'm already running too fast" or "time to raise the nose" during the take off run and make a marginal take off or even stall the wing. You simply have to IGNORE SUCH THOUGHTS and JUST RUN for as long as it takes.

You should not be afraid to run a long distance. Run 100 or 200 or even 300 metres if needed, no problem with that. Just run and accelerate and resist the urge to "push the nose up" or allow the nose angle to increase too much. The wing will lift you when it is time to lift you - while you are moonwalking at an ever higher speed with full throttle. If you are not happy with something, just spit the mouth gas and abort the take off by making a flair on the ground. You can abort the take off whenever you want, which is not something that you can do when you launch from a mountain.

You have to keep away all the "mountain launch" thoughts that will go through your head once your running speed becomes high and continues rising. Just remember that the faster you run, the more normal and safe your take off will be. And it is TOTALLY OK if it takes you 5 or 10 or 15 seconds of running before you lift off the ground and start flying. Needless to say that your first attempts should be done in a light steady wind to help your wing start flying as soon as you take your first steps. And don't forget: even with some headwind you are still going to commit to running and accelarating as much as possible. Obviously such long runs will require a LOOOONG field with no obstructions or features that cause mechanical turbulence.
From the above we can conclude that any possible mistakes where the pilot stalls the wing during take off can be attributed either to the mountain-launch-power-of-habit or to bad choice of take off field.

Make sure your engine & propeller gives out maximum thrust:

Small differences in the output performance of your engine & your propeller can have a big effect on the amount of thrust you get out of your Mosquito. Make it a habit to check your mechanical parts before every flight. They should be in good working order and performing to the max.

- The mouth gas and chest regulator should make the carburetor arm touch the stop block so that full gas from the pilot corresponds to full gas for the engine. Both throttle regulators should function perfect. It is very important that the mouth gas functions extra smoothly and without much effort.
- The oil mixed in the fuel should be of the highest quality with 5% per volume recommended.
- The air filter should be clean of dirt (visible) and oil (not visible) so that air can freely rush into the engine.
- The spark plug should be free of soot and have a dark brown hue to it. The engine should be easy to start and run at the correct air/fuel mixture.
- Servicing the engine requires specialised knowledge and equipment. GoCart mechanics will normally repair and service the engine at a minimum cost in terms of money and time.
- The propeller should be well-balanced and rotate with as little vibration as possible. The more a propeller vibrates the less thrust it produces. If in doubt, take your propeller to your local air club for balancing. The Swedish Aerosport fixed composite propeller will typically produce the highest static thrust.
- The optimum angle-of-dangle during straight horizontal flight is body position & harness totally parallel to the ground. It causes minimum air friction and maintains the correct thrust vector (engine pushing parallel to the direction of motion). If you find it uncomfortable for your neck to fly totally parallel to the ground then you may lower the motor-end of the harness around 2 to 5 degrees so that your feet are lying a bit lower than your head. Exceeding these angles will reduce the useful thrust of the engine and make take off and climbing more challenging.
- Taking off from sea level / low altitude will be much easier and safer than taking off from a high altitude plateu. If you are new to FLPHG then you should consider doing your first few flights at sea level (in dense air) before attempting to take off in thinner air. Bear in mind that taking off from a high altitude plateu will negativelly affect both engine performance & wing performance.
- The take off field has to be as big as possible, flat and free of obstructions. The surface has to be free of anything that might cause friction on the mosquito legs: fine deep sand, high grass & vegetation, water puddles, mud, gropes etc. Such features will not only increase the friction and required extra running but even pose a danger of tripping over.

Make sure you are comfortable with your Mosquito, your wing and your technique:

- Train on a big field before attempting to fly. Choose a day with light steady wind and run repeatedly on the ground until you have managed to get into a correct FLPHG-moonwalk: without getting tired while running, without lifting off the ground and without having control difficulties. Typically you should be able to moonwalk with the engine throttle at 40-50% power for as long as you have field in front of you. Once you have managed to moonwalk a few times without finding it difficult/challening/scary/tiresome then you are ready to make your first take off. And if you can moonwalk fast without problem then you can also moonwalk a bit faster and lift off.
Attempting to moonwalk or take off in shifting wind is not possible. Any running or flying will have to be done in steady, light, turbulence-free wind. Take off in zero wind is more challenging and requires that you have first developed a solid take off technique in light wind.
- A correct moonwalk also requires good control of the mouth gas. A well-functioning mouth gas will take a few tries to master. Typically you will be able to increase the throttle while running but not decrease it (you will have to spit it out and let the engine go back to idle).
- A modern single surface hangglider is the best and easiest way to get into FLPHG. Wings like the Icaro Piuma, the Falcon 4 and the Malibu 2 are ideal for learning to fly and becoming comfortable with your Mosquito NRG. Older models (especially wings from the 90's) are to be avoided.
- If you have a glider with VG then it is recommended to train your moonwalks with no VG at all. Even take offs should be made with no VG. It ensures that your wing will start flying and give your hands feedback in the shortest possible time.
- The hang point for Mosquito NRG will normally be the same as with free-flying harness. You want the center of gravity to be neutral just like it is with free flying, that means that you should be able to release the speedbar and slow down to a trim speed that is around 2-5 km/h faster than stall speed.
*** If your trim speed is very near or same as your stall speed then you can try moving the hangstrap one position forward.
*** If your trim speed is way higher than your stall speed then you will experience more challening take offs, very slow rate of climb and uncomfortable flying. In that case you can move the hangstrap one position back and test to see if there is some impovement.

Disclaimer: This tutorial is by no means enough to get you safely up in the air. Please enquire with your country's central HangGliding organisation about flying schools and certified FLPHG instructors offering training courses.

Additional information about the above video:

Power Unit: Mosquito NRG with internal fuel tank
Hangglider: Wills Wing T2 with max hook-in weight 107 kg
VG setting: No VG at all during take-off
Weather: Steady wind around 5 km/h
Weight: Hook-in weight 105 kg (pilot + Mosquito + full fuel)

Share |


Did you know that...

Icelanders drink more Coca Cola per capita than any other people?
Design & CMS av Webzoo AB