Paramotoring: The essential guide preview

LEARNING TO FLY IN COMPANY PFLYING ‘This book should be at the top of every pilot’s checklist’ – Tom de Dorlodot R ELEVEL HOW WE FLY LOW VIEFLYING W REFLEX EXPLAINED COLD CLIMATE FLYING CHOOSING A GLIDER THE SPARK PLUG THE DIFFERENT TYPES OF ADVENTURE TOURING ENGINES RAPID DESCENT TECHNIQUES CHOOSING A PARAMOTOR POST-FLIGHT INSPECTION ENJOYING YOUR FLYING TRAVELLING WITH YOUR RUNNING IN MOTOR HIGH, MEDIUM AND LOW TANDEM FLYING HANGPOINTS FLYING TRIKES THRUST, TORQUE AND COMPETITION FLYING GYROSCOPIC PRECESSION ECONOMY TASKS AIRSPEED AND GROUNDSPEED SLALOM FLYING FITTING YOUR SPEEDBAR PYLON RACING THE ULTIMATE PRE-FLIGHT UNDERSTANDING THE FUEL CHECKLIST SYSTEM LAYING OUT THE WING UNDERSTANDING RISK THE PERFECT LAUNCH AVOIDING ACCIDENTS HIGH WIND LAUNCHES KILLING THE MOTOR SPEEDBAR AND TRIMMERS RESERVE PARACHUTES CONVERTING FROM THE CARBURETTOR PARAGLIDING CARB ICING or visit your local school NAVIGATION AND FLYING XC paramotorFUEL CONSUMPTION SPOT LANDINGS BASIC PROPELLER REPAIRS LANDING REFLEX GLIDERSand friends ETHANOL AND YOUR ENGINE

PARAMOTORING The Essential Guide THAT WAS JUST A PREVIEW TO FIND OUT MORE AND BUY THE BOOK VISIT www.xcshop.com

DEAN ELDRIDGE

PARAMOTORING THE ESSENTIAL GUIDE DEAN ELDRIDGE and friends

In the core, since 1988

About this book

Flying is our passion, and this book reflects that. It started out as a collection of the best instructional articles published in Paramotor Magazine, but evolved, got bigger and expanded. The result is what you have in your hand – 220-plus pages and over 50 chapters dedicated to the art, skill and pleasure of flying powered paragliders. The book is aimed at anyone who already flies or wants to fly a paramotor, and is designed to be an aid to, not a replacement for, proper instruction. If you have done or are doing a course, it’s for you. With Dean Eldridge at the helm the book is designed to be best used as a reference manual, for dipping into and learning more or refreshing knowledge with some revision as you progress through the sport. You will find some theory inside here, but mainly you will find hard-won practical experience, explained in a simple way by pilots who have been there and done it many times before. It’s quite simply the best of what paramotoring is all about. Enjoy the book – and see you in the air.

About Cross Country

Cross Country International has been involved in publishing magazines and books about hang gliding, paragliding and paramotoring since 1988. The company has always been owned and run by pilots, and always will be.

Publisher’s info

Cross Country International Tollgate Beddingham Lewes BN8 6JZ UK www.cross-country-int.com Published 2014. Photographs and text copyright Cross Country International Ltd. All rights reserved. No part of this book may be reproduced in any form or by any other means without permission in writing from the publisher. Paramotoring is an evolving discipline: theories adapt, equipment is superseded and advice changes. Please let us know at editor@xcmag.com.

Author: Dean Eldridge and contributors Editor: Ed Ewing Designer: Marcus King Editorial team: Louise Joselyn, Charlie King, Hugh Miller Sales: Verity Sowden ISBN: 978-0-9570727-7-0

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There is an art to flying Douglas Adams, Life, the Universe and Everything

�

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CAPTAIN DEANO “I’ll be in charge of your flight today.”

Photo: Sophie Bolesworth

WELCOME TO OUR WORLD WELCOME to the amazing, highly addictive and enviable world of paramotoring.

Whether you are eagerly anticipating your first flight, are looking to improve some skills or are a well seasoned pilot, you should find something of value inside this book.

The contents are a culmination of flying experiences I’ve gained over the last 20 years of being a pilot. There are also many contributions from other well-respected pilots from around the globe. It’s been my privilege to spend time with them over the years – thank you folks.

The wonderful characters at Paramotor Magazine and Cross Country have put in an amazing amount of work and energy to combine and organise everything you read and view here, so infinite thanks to them too.

While I’m able to extend some appreciation, I’d like to thank both Parajet and Paramania for supporting me over the years.

In the following pages you will find technical tips, help with a wide variety of launch, landing and flying techniques, some superb pointers on keeping safe and staying

legal and plenty of advice to help keep you and your equipment in top shape.

With paramotoring we have the most incredible form of motorised aviation. It is the dream of many, to have a wind-in-theface flying machine that not only fits into your car or can be packed into a suitcase, but that can be launched from laughably small spaces. The possibilities for improving our flying experiences are limitless, the locations that it’s possible to fly are endless and we are still at the pioneering stage with equipment improving every year.

We also have a great deal of freedom in most places around the globe and we really need to look after this great privilege and keep it that way, for all to enjoy for many, many years to come. Keep reading and not only should your own future flying experiences be enhanced but maybe others involved in the most wonderful form of flight there is will benefit too. Wishing you pleasant reading, safe and happy flying.

Dean Eldridge

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ď‚ƒHEAD IN THE CLOUDS The privilege of flight is ours. Cruising in France.

Photo: Franck Simonnet / Dudek

CONTENTS 7 Introduction 12 Contributors 15

Learning to fly, by Dean Eldridge

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How we fly, by Dean Eldridge and Ed Ewing

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Reflex explained, by Mike Campbell-Jones

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Choosing a glider, by Dean Eldridge

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The different types of engines, by Dean Eldridge

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The propeller, by Dean Eldridge

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Buying secondhand, by Paul Mahony

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Running in your motor, by Dean Eldridge

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High, medium and low hangpoints, By Dean Eldridge, with Paul Haxby, Eric Dufour, Dani Martinez and Sascha Burkhardt

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Thrust, torque and gyroscopic precession, by Dean Eldridge

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Airspeed and groundspeed, by Dean Eldridge

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Fitting your speedbar, by Dean Eldridge

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Converting from paragliding to paramotoring, by Alex Ledger

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Fit to fly, by Dean Eldridge

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The ultimate flight preparation, by Dean Eldridge

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Laying out the wing, by Dean Eldridge

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The perfect forward launch, by Dean Eldridge

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The reverse launch, by Dean Eldridge

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Speedbar and trimmers, by Dean Eldridge

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Navigation and flying cross country, by Neil Slinger

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Landing on cross country flights, by Tony Gibson

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Landing reflex gliders, by Dean Eldridge

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Spot landings, by Edward Lichtner

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Flying in company, by Dean Eldridge

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Low level flying, by Sascha Burkhardt

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Cold climate flying, by Dean Eldridge

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Flying over water, by Dean Eldridge

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Adventure touring, by Ed Ewing

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Flying wingovers, by Edward Lichtner and Tom de Dorlodot

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Rapid descent techniques, by Dean Eldridge

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Post-flight inspection, by Dean Eldridge

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Travelling with your paramotor, by Dean Eldridge

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Tandem flying, by Edward Lichtner

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Flying trikes, by Sascha Burkhardt with Ludovic Migneaux, Andy Phillips, Daniel Crespo and Pascal VallĂŠe

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Competition flying, by Dave Hairs

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Economy flying, by Neil Slinger

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Slalom flying, by Michel Carnet

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Pylon racing, by Pascal Campbell-Jones and Dean Eldridge

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Setting records, by Michel Carnet

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Understanding risk, by Dean Eldridge

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Avoiding accidents, by Klaus Irschik

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Killing the motor, by Marcus King

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Reserve parachutes, by Edward Lichtner

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Why your engine is expensive, by Dean Eldridge

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The carburettor, by Thomas Keller and Sascha Burkhardt

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Carb icing, by Marcus King

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Making basic repairs, with Paul Haxby, Tony Gibson, Emilia Plak and Chad Bastion

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Basic propeller repairs, by Dean Eldridge

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The spark plug, by Dean Eldridge

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De-coking a two-stroke, by Dean Eldridge

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Understanding the fuel system, by Dean Eldridge

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Ethanol and your engine, by Dean Eldridge

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Fuel consumption, by Dean Eldridge

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Enjoying your flying, by Dean Eldridge

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Index and glossary

236

The author

ď‚‚GO WITH THE WIND Photo: Franck Simonnet / Swing

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CONTRIBUTORS Chad Bastion

Instructor in California and pioneer of the sport in the States

Sascha Burkhardt

German pilot and paramotoring journalist

free-flight

and

Eric Dufour

National champion, instructor and pioneer of paramotoring in the USA

Ed Ewing

Editor of Cross Country magazine, assistant editor Paramotor Magazine

Mike Campbell-Jones

Tony Gibson

Pascal Campbell-Jones

Dave Hairs

Michel Carnet

Paul Haxby

Daniel Crespo

Klaus Irschik

Dav Dagault

Thomas Keller

Designer with Paramania and pioneer of reflex technology Paramania team pilot and founder of the Parabatix pylon racing team Multiple British Paramotor Champion and Paramotor World Champion 2009 Spanish team pilot, instructor and world record holder Designer and chief test pilot with Ozone

Tom de Dorlodot

Red Bull adventure pilot and founder of the Search Projects

Bob Drury

South African paramotor champion and instructor with Flying Unlimited British competition pilot and world record holder British paramotor instructor with AXB Paramotoring and photographer DHV instructor, completed a dissertation on safety and paragliding German paramotor champion and trike world record holder

Marcus King

Editor of Paramotor Magazine, associate editor of Cross Country

Editor of Cross Country magazine 20052010 and writer for Paramotor Magazine

Alex Ledger

Piotr Dudek

Edward Lichtner

Designer, instructor, founder of Dudek and flying since 1987

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UK instructor and secretary of APPI PPG French pilot, journalist and contributor to Paramotor Magazine

Paul Mahony

UK instructor and BHPA Flying and safety committee member

Dani Martinez

Spanish pilot, instructor European Champion

and

former

Ludovic Migneaux

French pilot and instructor with Atlantic Paramotoring

Cover photo Louis Garnier

Illustrations Charlie King Marcus King

Support

UK pioneer and member of the British team

When we first aired the idea of this book several manufacturers were quick to offer their support, allowing the project to get off the ground. Parajet, Maillon Rapide and Ozone are all longterm supporters of paramotoring, Cross Country International and its writers and photographers. You’ll find their adverts towards the back of the book. Editorial independence was retained by the author and publishing team. Thanks to all for helping make it happen.

Pascal Vallée

Thanks

Andy Phillips

UK competition pilot and in 2000 first to paramotor the UK’s 1,200km ‘Tip-to-Tip’

Emilia Plak

Women’s world champion, adventure and competition pilot

Neil Slinger

Paramotor world champion member of the French team

Photographs

Apco, Paul Bailey, Sophie Bolesworth, Benedikt Bos, Sascha Burkhardt, Pascal Campbell-Jones, Ben Clowes, Francis Cormon, Nigel Davies, Tom de Dorlodot, Piers Dent, Air Design, Iwona Dudek, Dean Eldridge, Ant Green, Jeff Hamann.

Harris C., Paul Haxby, Kangook, Marcus King, Panagiotis Konstantinou, Alex Ledger, Horacio Llorens, Jeremias Marinovic, Jorg Maas, Ozone, MacPara, Alex Mateos, Douglas Noblet, Nova, Mike Nunn, Parajet, Paramania, Emilia Plak, Polini, Mathieu Rouanet, Chris Santacroce Franck Simonnet, Elina Sirparanta, Karen Skinner, Sky Paragliders, Swing, Karan Thapa, Frances Valdez, Pascal Vallée, Olivier Vietti-Teppa, Jason Whitehead.

Creating any book is a time-consuming labour of love, and this one was no different – but it was made a lot easier by the contributions and generosity of all those listed on these pages (as well as probably some we have forgotten to mention, for which my apologies). Thanks to all of them, especially Louise Joselyn, Charlie King and Marcus King for making the production of this book a lot easier than it could have been.

Also thanks to Deano for his boundless enthusiasm for the project. From taking Skype calls in Switzerland to responding to emails while floating in the Indian Ocean, he was always ready to answer numerous queries and send in yet one more revision.

Thanks also to all the readers of Paramotor and Cross Country magazines and to those who have bought this book – nothing happens without your continued support.

Ed Ewing, editor

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ď‚„FLY IN PEACE The Peace Pagoda in Pokhara, Nepal.

Photo: Marcus King

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READY TO GO UK instructor Paul Mahony instructs Verity Sowden.

Photo: Marcus King

LEARNING TO FLY

By Dean Eldridge WE ARE all introduced to our sport in different ways: we either see others flying around, hear about it from friends and family, or maybe transition from another aerial activity like skydiving or paragliding.

For me it was the latter. For more than 10 years I had enjoyed the peace and tranquility of paragliding – but it must be said I’d had a few scrapes and spent more ‘para-waiting’ hours on the tops of beautiful hills during that time than flying hours. “What’s needed is one of those motor thingies!” I told myself, and that’s where my life’s journey took an unexpected but totally wonderful turn.

Beginner’s mistakes

I had a trusty old beginner/intermediate wing at that time and I thought all I had to do was strap any old motor on my back and all would be fine – I’d soon be racking up those extra hours.

Thankfully, my first untrained motorised ‘flight’ with a cheap and nasty paramotor purchased from an online auction site didn’t end in disaster, but it very well could have.

However, it only lasted from one end of the field to the other before I realised I really didn’t know what I was doing (I was also only just out of restricted airspace).

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There is absolutely no substitute for first class tuition

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Adding up all my nervous setup time, an hour trying to get the damn motor started and a couple of scrappy, aborted launches that almost ended in broken equipment, I was worse off flight-time-wise and more out of pocket than I was when para-waiting on the top of the hill.

It was then I decided to get a little instruction.

regulated in your country, any instructor or training school or facility worth their salt will be teaching to a recognised syllabus.

They will offer courses that encompass not only the physical elements of learning to fly but also include lectures and videos on the theory of flight, air law, meteorology, motor forces, variations on equipment and the rest.

Know the regulations

Should you book a week course or go day by day?

There is absolutely no substitute for first class tuition when you initially get bitten by the paramotoring bug. You are taking to the skies with a bag of fabric over your head and what could potentially be a bluntedged meat-slicer on your back into possibly congested airspace – who wouldn’t want to be taught properly?

With good, thorough training by a recognised instructor you immediately reduce the risk of disaster and very quickly become comfortable with your equipment and being aloft with it.

Many countries now have mandatory training. You need it to be able to fly a paramotor legally and you will have to display a number on your wing. This is what we call regulated. Other countries, including the UK, Belgium and USA, for the time being, do not. This is called de-regulated.

Whether the sport is regulated or de-

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Not everyone is able to take a week or two off work or away from family commitments to take a dedicated course, but from my experience this is by far the best method to really soak up and absorb all that is necessary to safely take to the skies. Paramotoring is quite physically demanding initially, especially for those not used to romping around a field trying to get a wing above their head, but most folks find sucking nice clean air and the release of endorphins extremely satisfying.

Having a half-day every other weekend is better than not, but you’ll probably end up having to re-learn all the vital info you gained from the previous lesson. However, extra half-days can also be very beneficial – they help you get out there in your local field and get those launch techniques up to scratch in between lessons.

Word of mouth

Most good instructors and training centres have a spotless reputation and are kept busy mainly through word-of-mouth. So many new, aspiring pilots attend courses from those they have been influenced by or have heard about. Magazines specific to our form of flying also offer adverts for recognised training and a search through the internet will soon give you an idea of where to go to seek expert advice.

Be wary of instructors or teaching facilities that try to sell you a bunch of new equipment before you’ve even had a chance to try a motor on your back. Although some folks will want to learn on their own kit, it shouldn’t be a requirement.

Different approaches

There are numerous approaches to getting someone’s feet off the ground for the first time (and hopefully bringing them back down again with a great big smile on their face!). It would be wonderful if the same standard and techniques were available in every corner of the globe, however, different locations require different methods. There are some organisations and some countries where you are required to have completed a basic paragliding course from a hill first, but there are also other, safe methods of ground training before an aspiring pilot makes their first powered solo.

For example, there is the towing method, either by winch or hand-tow, although this should only ever be done with the correct equipment and with an instructor who’s

very experienced with the techniques.

Personally, I also love to include a tandem powered foot-launch flight as part of any training. The feedback I get from students, as well as their subsequent success on first time powered solo launches, proves this method is useful. It is also a first-class seat for the instructor to observe the student when they take the controls and, with the correct communications setup, to discuss all the elements of the flight as they happen.

Learn properly and avoid developing bad habits

There will still be some folks who will go out there and try to teach themselves or learn from a friend. All I can say is that they will only end up with potentially bad or even dangerous habits that are difficult to shake once they have them. Learning the right techniques from the start will provide a firm foundation, giving you the best start possible for many wonderful years of glorious flight.

NEED TO KNOW • D on’t try and teach yourself • Do seek a recognised, recommended instructor • Get ready for a bit of ‘physical’ • Don’t be persuaded into buying all the new kit before doing your training • The training you get at the start will be the foundation of your flying for years to come – invest in it now and avoid developing bad habits in the future

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REFLEX EXPLAINED

By Mike Campbell-Jones THE BIGGEST evolution in paramotoring, aside from improved engines and better understanding of frame geometry, is the introduction of reflex profiles. It is now generally recognised that they have helped turn our sport into a practical, fun and relatively safe form of flying.

In the early 1980s similar developments took place when pioneers began bolting engines onto hang gliders. While these early ultralights flew, they were not ideal, because wings designed for power have very different requirements. I was privileged to have been a part of those early pioneering days. My experience spans hang gliding, ultralights, general aviation, gliding, ballooning and paragliding to my present day passion for paramotoring. This experience proved invaluable when developing the original Reflex paramotor wing in 1994.

Used in a paraglider reflex profiles have a different effect, because unlike hang gliders the angle of attack is maintained through the lines connected to the pendulum weight of the pilot suspended below. This works in the same way as a wing with a fuselage and a tail-plane, as a lever, controlling the wing’s angle of attack.

Reflex profile enhances this pitch-stability, by adding an effective elevator into the wing, whilst keeping the centre of lift/pressure close to the leading edge. The wing-loading is higher (as less of the wing’s area is used for lift) so stability and speed are increased without the need to change angle of attack.

There are other factors, but the end result is there is more efficiency at speed and a greater range between cruising and stall speeds (a flatter polar curve), leading to safer flying. For us, this is an exciting development.

What is reflex?

Pitch stability

Reflex profiles are not new: they were first used extensively as far back as the 1930s in tail-less aircraft, such as the Horten brothers’ flying wings or the Fauvel tail-less glider. It gave these wings the aerodynamic pitchstability normally produced by a tail-plane.

Hang glider designers also adopted reflex.

It improved safety as it helped prevent tumbling. The effect was simple enough: more reflex, more pitch-stability, though less speed and performance as the angle of attack was increased.

Pitch, roll and yaw are the three types of stability vital to any aircraft. They make up the three axes of control for most aircraft.

For paraglider wings the first two matter most, especially in those developed for powered use, due to the low slung mass of pilot/engine and the gyroscopic and torque effects of the propeller thrust.

Inherent pitch-stability is easily recognised in normal flight whilst flying through thermals or areas of turbulence, and can be defined as:

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30%

15-20%

15%

Full Speed

CENTRE OF PRESSURE The classic paraglider (top left) has its centre of pressure at about 30% along the chord, making it pitch negative – it pitches back in lift. The reflex glider has its centre of pressure further forward at about 15-20%. It is pitch positive.

At speed the centre of pressure shifts further forwards. The result is increased stability. Illustration: Marcus King

• If the aircraft pitches forward as it enters the thermal and backwards as it exits it is pitch positive.

• If the aircraft pitches backwards as it enters a thermal and forward as it exits it is pitch negative.

This movement is very noticeable on paragliders because the centre of gravity is so far below the wing, a long way from the centre of lift / centre of pressure compared to most aircraft.

For maximum efficiency performance paragliders have a centre of pressure around 30% along the chord from the leading edge, which makes them inherently pitch negative. The wing’s stability is dependent on the pendulum effect of the centre of

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gravity (pilot weight) to control the angle of attack. In turbulence the centre of gravity changes. Imagine flying an aircraft where the size of the elevator changes in flight!

This is why paraglider pilots are taught to fly actively in turbulence, to constantly control the pitch of the wing with the brakes – otherwise large changes in angle of attack can and do cause collapses. Indeed, some wings are even designed with more sensitive pitch control to enhance feedback.

Lower performance paragliders generally have more pitch stability to reduce the input required of the pilot to keep their wing open: this is considered safer. Designers generally achieve this by using flatter wing sections, which results in the centre of pressure being

ď‚ TWO-STROKE The cheapest and most popular option.

Photo: Marcus King

ď‚ FOUR-STROKE Reliable and easier maintenance.

Photo: Marcus King

THE DIFFERENT TYPES OF ENGINES

By Dean Eldridge WHEN it comes to choosing a type of engine for a paramotor, given the general criteria of maximum power and minimum weight, most will opt for the two-stroke variant with its relative simplicity as an added bonus. Below we will discover why this is but also look at the options and their pros and cons.

The Two-Stroke

Despite their decline in popularity in just about every other sport due to increasing

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emissions regulations, two-stroke engines are by far the most popular choice for the paramotor pilot. This is because they currently offer the best power-to-weight ratio of any production-based engine.

By producing one power stroke for each revolution of the crankshaft and negating the need for heavy and complex valve-driven intake and exhaust systems, the little twostroke packs a big punch for its kilos.

Mechanically it is also very simple, which is very appealing for most, but occasionally

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Two-stroke engines are the most popular choice

they do tend to be a little finicky, with some becoming very cantankerous with slight changes in altitude, temperature and humidity. Two-strokes also require a finelymeasured amount of high-quality specialist oil mixed with their fuel as they do not have a separate lubrication system. This, along with the correctly tuned fuel/air ratio from the carburettor is absolutely critical if you don’t want to end up with melted internals.

The Four-Stroke

Most other internal combustion engines in many forms of transport are four-strokes.

This is due primarily to their reliability, economy and extensive investment from many sources over the last century.

This should be a big plus for paramotor pilots too, but until quite recently they were incredibly heavy and underpowered due to being adapted from engines made for other applications rather than being built specifically for our purpose. Now however, albeit expensive, we are seeing lighter, more powerful four-stroke engines becoming ever more popular within our sport, especially for those favouring cross-country and/or requiring a more ‘turn-key’ approach to their flying.

With the added bonus of only requiring neat/ straight fuel instead of mixed and not being so fussy about its quality either, it’s no wonder that the four-stroke is finding more friends.

A four-stroke though will not make its power as quickly as its two-stroke stablemate, and with the recent trend moving to smaller, more agile wings requiring increased power, the four-stroke is lacking a little in the oomph stakes.

Electric engines

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With the apparent negative points surrounding petrol-driven, internal combustion engines, for years many pilots have been dreaming of the electric-powered paramotor that would give them everything: quietness, power, ease of maintenance etc.

Well, it is actually possible to have all this and more (compactness, cleaner, greener etc) but always at the expense of cost, autonomy and longevity.

The motors themselves are fairly inexpensive but the batteries, controllers and chargers still put the cost of an electric paramotor way beyond the price of a conventional one. Plus the batteries themselves have a charge cycle life, are heavy and sometimes volatile. Many years on from the first ones and we are still only seeing sub 30-minute flight times. Plus you always have to land with the same weight compared to shedding kilos during flight on a petrol motor.

That said, electric engines are gaining popularity with a small group of paraglider pilots, enabling them to keep aloft on light or non-thermic days or maintain height between thermals. Their compact nature means they can fit into a standard looking harness and, because the engine for a paraglider pilot isn’t in use all the time, the engine has greater autonomy than for us power-hungry mongrels.

Rotary engines

There is another type of petrol engine that has a better power-to-weight ratio than a two-stroke, is as reliable as a four-stroke and

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Torque

Thrust line

Propeller spinning anticloclwise

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ON THE RUN Torque opposes the force of the propeller.

Photo: Franck Simonnet

THRUST, TORQUE AND GYROSCOPIC PRECESSION

By Dean Eldridge IT IS commonly believed that the physical force enabling us to fly is the wonderful ‘lift’ that pulls us up against gravity and the ground. But to create this lift we need a precise balance of the other forces, notably speed, drag and weight. The optimum mix and balance of these forces will enable a wing to have lift and therefore a certain glide.

However, our paramotor comes with its own set of forces of which we should also be aware.

These other elements help keep us in the air.

Thrust

Thrust is purely and simply the amount of force that is pushing forward, and is measured in terms of the kilograms of force it would take to hold it back. So 50kg of thrust would take a an opposing force of 50kg to hold it back.

Taking off requires a decent amount of the stuff. As we know, we have to accelerate to create speed over the wing, which creates some of our lift, and then we have to keep that thrust coming to enable us to climb out. Once up there though, on a correctly sized wing, it actually takes around half the amount or less of that thrust to keep us aloft. If we want to fly our wing faster we have to increase the amount of thrust accordingly, either to remain on level flight or continue climbing.

Thrust has a direct impact on the pitch of the wing too. We are akin to a pendulum underneath our wing, so care has to be taken when coming quickly on and off

the power. Cruising along nicely and then suddenly dropping the power will cause us to swing back under the wing and for the wing to pitch noticeably ahead of us.

Instantly squeezing on a load of power would see us swing forwards under the wing and consequently the wing pitching back behind us. The first time you try this should be under instruction as learning to control pitch is an important part of becoming a pilot, otherwise you might end up wearing your breakfast, or worse, your glider.

Torque

A consequence of having just one propeller spinning in a certain direction means that everything else that propeller is attached to is trying to turn in the opposite direction.

Remember, for every action there is an equal and opposite reaction. This is called the torque effect and is NOT the amount of torque the engine makes as in automotive engine specs.

Imagine a propeller spinning really slowly and you grab hold of it. Suddenly everything else would spin in the opposite direction.

Similarly, if you are holding an electric drill while boring a big hole and it suddenly ‘grabs,’ you immediately have a drill that wants to rip your hand off in the opposite direction.

The effects of torque on a paramotor can be quite significant. It all depends on many factors, including weight of the propeller, whether it

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ď‚„ON LOCATION Winter coastal flying in Spain.

Photo: Marcus King

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DON’T LOOK DOWN Stand up, don’t lean forward.

Photo: Alex Ledger

CONVERTING FROM PARAGLIDING TO PARAMOTORING

By Alex Ledger PILOTS often think it is simple to switch from paragliding to paramotoring, but as a paramotor instructor I have not found this to be the case. I reckon 20% of my students have had some form of paragliding experience before paramotoring. Once paraglider pilots are airborne they are in their element, and the actual flying is very similar to what they are used to, but getting airborne and landing require different techniques.

Launch techniques

The differences are subtle but extremely important. I teach in the UK and when a paraglider pilot takes off here it is often in strong winds using a reverse launch technique, with no need to run very far before getting airborne. A typical launch would involve the pilot launching the wing with an A-riser and toggle in each hand, inflating it above his head, applying both

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“

Taking off is optional and landing is compulsory

brakes to stop it overshooting and then turning, leaning forward and running down the slope.

Paraglider pilots who are used to flying in the mountains in light winds usually use the forward-launch technique – leaning forward and running off the edge of the slope. This technique, like the UK take-off described above, when used with a paramotor would likely end in disaster. In order for paraglider pilots to learn how to take off correctly with a paramotor, they effectively need to be untaught and then re-taught, which is easier said than done!

Groundhandling

The most important thing is groundhandling, as every paramotor pilot knows. You need to be able to keep the wing directly into wind while taking off on flat ground.

When launching with a paramotor pilots are unlikely to get away with errors such as drifting off the wind line, lifting their legs, jumping into the seat, applying brake etc.

In my opinion the best way to reverselaunch a paramotor is the A and D method: Take the A lines and left toggle in the left hand, and the D lines and right toggle in the right hand along with the throttle.

Then build a wall directly into wind, and launch the wing using the D lines to stop it overshooting. This avoids the risk of the hands getting too close to the prop while applying the brakes.

There’s more on this later in the book, but for now suffice to say the A and D method can be learnt in a matter of minutes and offers good control of the wing without even

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being clipped into the harness. With plenty of groundhandling practice it all becomes second nature.

Don’t lean forward

Another tendency paraglider pilots have when launching is to lean forward when taking off. Without a motor this aids launch by pressurising the leading edge, but the thrust from a motor simply pushes a body in this position diagonally downwards.

Paramotorists need to stand up straight and allow the thrust of the engine to push their body horizontally forwards to launch.

When to brake

Paraglider pilots often apply both brakes to stop the wing from overshooting during launch. But when paramotor pilots take off in light winds it is important to generate forward speed first, which means hands-up while applying power and running forward into wind. Only when they approach the take-off speed should they apply a touch of both brakes to allow the wing to take off in a smooth and controlled manner.

Keep running

Finally, some paraglider pilots have a tendency to jump or lift their legs immediately after taking off from a hill in order to get straight into their seat.

This is bad practice in free flight, but will have dire consequences when done with a paramotor. Pilots must keep running, even when they feel they are close to the takeoff point. This is particularly important

POINT OF VIEW Good preparation is key.

Photo: Benedikt Bos / BGD

THE PERFECT FORWARD LAUNCH

By Dean Eldridge A PERFECT launch is paramount to avoid frustration and fatigue. There’s nothing worse than struggling on the ground to lay out again while your friends are already in the air.

The forward launch seems to give the most grief, especially in those nil- or lightwind situations, when you just know there are glorious flying conditions up in the air.

It is worth taking the time to really learn to nail the forward lauch – practice makes perfect as they say.

Equipment setup

The first element to the perfect launch is immaculate preparation and equipment setup. This is well described in the previous chapter, so no need to go into it here, but with practise this need not be a time-consuming exercise.

The aim is to achieve a flawlessly laidout wing in a nice crescent shape, angled so that the cells are facing into wind and the tips form a symmetrical arc. This takes two minutes maximum.

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Positioning and posture

Assuming you have positioned yourself in a place with ample take-off space, and have an engine on your back that has been rigorously checked and delicately warmed, clip into your wing, noting not to step too far away from it and upsetting all your hard work.

Have your throttle control and brakes in hand and place the A-risers in the base between thumb and forefinger or however your equipment allows you to get a good purchase on them. The only thing running underneath your arms should be the throttle cable.

With arms outstretched in a ‘twenty-pasteight’ position very gently walk forward until you feel light pressure equally in both hands from the A-risers. Don’t walk forward too much as you could pull the leading edge of the wing over and make launching a much less elegant affair.

Those with high hangpoint motors will probably need to have their hands higher, maybe in a ten-past-ten position. Step left or right accordingly and when everything seems equal take a good two strides straight backwards, keeping your hands in the same position.

Reflection and focus

Once your engine is running and everything is set up correctly as described, you now have a little time to reflect and focus on what you are about to do and mentally prepare.

One key point to a perfect forward launch is to actually visualise doing it and to enjoy it, not endure it. Remind yourself you need commitment right from the start: to continue forward momentum, to not decrease speed (unless it is necessary to abort the launch), to drop the A-risers at the correct time and apply the power fairly quickly if all feels good above, or make a

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little correction if necessary.

Remember also that it takes speed over the wing to create lift. You must keep your hands high so you are not inducing drag, and you may need to run a little faster than you were. The golden rule is to keep running even when your feet come off the ground.

It used to look super cool to hop into the seat as soon as your feet departed terra firma, but actually a few little air-steps as you climb away from the ground can appear just as cool. Certainly it’s a lot cooler than jumping into the seat too early and fluffing yet another launch.

Semi-power launch

Some top guys and girls use a little power as they initiate their forward push. But this should only be done if you know what you are doing, and when your lines go tight you are not going to pull your cage into your wonderfully crafted, spinning propeller.

Some cages allow this to be done, others, especially lighter machines, definitely don’t.

As an alternative you can give the engine a good rev-up confidently and safely while standing static, if you have the correct posture.

This clears the throat of your motor if it has been idling for some time and gives you the reassurance that it is making full power.

It also creates a very useable flow of air above the wing.

What seems to work with most folk is to have one foot in front of the other, the front foot pointing straight forward with the knee locked straight, the rear foot off at 30 to 45-degrees and bent slightly at the knee, with an additional slight bend forward at the hips.

In this stance, and with your hands and controls as described above, it is safe and easy to apply power in the static position to create this flow of air up and over your elegantly laid-out wing.

WHICH WAY NOW? Learning to navigate is crucial – and enjoyable too.

Photo: Marcus King

NAVIGATION AND FLYING CROSS COUNTRY

By Neil Slinger NAVIGATION is the first thing you do when you get airborne. Simply asking yourself, “where the hell am I?” sets you thinking about your place in the sky in relation to the ground.

“How fast?” and “can I get back?” are the next two questions that need an understanding of navigation to answer.

At the start of a flying career these questions can be answered easily enough by looking at the windsock in the field, or the height of the terrain around you. But soon pilots start to incorporate wind direction, wind speed

and a map into pre-flight planning.

If you do that pre-flight planning properly, in flight the unknown landscape passing underneath you becomes a series of landmarks on a pre-planned journey. It’s very satisfying to land when and where you said you would, and by thinking ahead and planning the journey the world opens up.

But beginners can feel totally inadequate in the face of air charts, with their confusing lines and blocks of legally imposed No-Gos. Perhaps, they think, navigation is better left

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to the guy who usually leads the group’s XCs? Not so. An evening spent studying an air chart can soon make reading the map fairly straightforward (if you can understand a motorway driving map, you can get to grips with an air chart). And from there, learning the real art of navigation can begin.

Is technology the answer?

The answer for many who can’t navigate is a GPS. For me, you might as well make love with a woolly sock on. Yes, it’s easy to use, one size fits all and you always get there … but some of the vitality of the freedom we are privileged to enjoy is lost. By vitality I mean that momentary connection you have with each village, stream, canal, railway, wood or farm that confirms your route. You carry visual memories of the flight way beyond a little LCD graphic. There is nothing better than knowing how to navigate properly. So here goes.

Back to school

Before getting in the air get a pencil case.

Stock up on Day-Glo highlighters, black and red markers in various nib sizes – fine and medium for black with perhaps one broad red – a 30 cm ruler, compass, divider, rubber, pencils and a small notebook. And then review the size of that pencil case.

For good measure get a calculator and pick up a couple of rolls of sticky-backed clear plastic to cover maps. Finally, get a small bottle of methylated spirits so you can wipe the map clean.

Learning the art

The first thing to learn is how to orientate yourself in the air using a map. There will be obvious landmarks which will guide you as you climb, but it is reading the map in such ‘terms of reference’ that can be difficult.

An idea worth exploring is turning the map to match the ground. Heading south? Look

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at the map with north in your belly, south furthest away. Matching familiar ground references will be far easier without having to twist the printed or physical image round in your head. The hill over there on the right is on the right on the map too.

A second art is using the compass. If you don’t know how to use one of these on the ground, then you never will in the air so the first thing to do is practise on terra firma.

Just remember the red bit points north.

In the air you will probably elect to use a globe compass rather than a flat compass, as the unsteady nature of flying means globe compasses ‘settle’ more easily in flight.

Getting used to a chosen compass is vital: tilt-quirks mean it can stop rotating; a small dial or watering eyes can all affect how easily it is read. Mounting it correctly is also important: putting it on the boot of a shaky leg can give Bermuda Triangle readings as you jiggle in the cold.

As with using a calculator, it is always wise to have an idea of the answer you expect from your compass, otherwise blatantly wrong results can be followed blindly. The sun will help: you just have to think ‘where should it be?’ In the northern hemisphere it rises in the east, travels through the south and sets in the west. It’s a simple tool but massively confidence boosting, and ignored at a pilot’s peril.

The Perfect Circle task

To help master navigating, try this simple fun task. Draw a 3km radius circle on a good local map that shows fields and individual farms. A route like this takes in all wind directions, giving plenty of track-accuracy problems. It is about 18km long but never far from home (the old adage ‘you’re never lost if you know where you came from’ can be applied here). It is short enough to fly twice – reversing the direction perhaps – and if you fly it with a GPS to record the

TURNING CIRCLE A competition setup with GPS, map and stopwatch.

Photo: Jörg Maaß

tracklog you can compare your track with what a circle really looks like.

The point of this is to learn about using a map in the air. First marking it up, holding it, turning it in the air, reading it (this is where you find out about goggle/glasses conflicts), interpreting what is on the map, matching map features to ground features and then triple checking all that you’ve deciphered.

You’ll discover that following a line on the map over field corners, clipping farms and river meanders is totally absorbing, so remember to look out for other air traffic.

Once you’re happy with that task, or as an alternative, try flying a straight line over a similar distance using different map-toground references. But this time instead of using the ground below to navigate by, fly by using two or three points in the distance

while keeping them aligned.

Both of these tasks are extremely satisfying.

Moreover, they will reveal a lot about your in-flight setup too. Did the marker pen obscure map detail and would a finer tip be better? Could you break the pen line so feature-detail is not obscured? Did the map flick up in your face or did you have to do the whole thing with the map stuck northsouth in your lap?

Mapping it out

In competition, pilots are normally given a good local map that covers the area in enough detail to permit navigation by ground features such as woods, streams and villages. If you’re not in a competition, then this is the first thing you should equip yourself with. Cover it in sticky-backed

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SPIT AND POLISH Keeping your machine clean is step one.

All photos: Marcus King

POST-FLIGHT INSPECTION

By Dean Eldridge WE all do pre-flight checks, but how many of us do a regular post-flight inspection? Any pilot who has flown in a competition will attest to the essential nature of post-flight checks. After all, it’s frustrating, not to say detrimental to your points haul, to find you need to make a 30-minute repair just five minutes before a task starts.

Post-flight checks only take a few minutes but are 100% worth it. To make sure nothing is overlooked, I’ll split the motor unit into three areas: harness, chassis and engine.

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Harness

Buckles: First of all check all the attachments on the straps open and close as they should. Many buckles need two fingers to open them: make sure they don’t open with just one, especially leg straps.

Webbing and stitching: Have a good look at the integrity of all the webbing and stitching while you are there too. Whatever configuration of machine and hangpoints you have, there will certainly be karabiners there somewhere. There are various ways of locking closed so check this thoroughly.

SHACKLES Check the shackles connecting the harness to the frame are undamaged and fully closed.

Sand, grit, dirt and other matter can get in there and stop them functioning properly.

Make sure they work perfectly: an open karabiner is not very strong.

Attachment points: Now have a good look at the webbing the karabiner is attached to and if you have low / medium attachments, the shackles going from this into the torque / swinging arms and also the shackles at the end of the arms.

Attachment of the harness to the chassis is very important. Sometimes this consists of just a couple of unsubstantial looking M6 bolts and nuts. It’s not the end of the world if you are still safely in your harness when your machine drops off your back, but it would be embarrassing, not to mention expensive.

Chassis

The chassis is often left out of flight checks if there haven’t been any heavy landings, knocks or bumps. However, there are a great many forces going through a chassis that can cause problems. From cage-squeezing from power launches stressing fixing points, to

WEBBING Check all webbing for wear.

damage caused during transportation and all the associated resonance and vibrations from the engine. In extreme cases these can even cause welds to break.

Start from your harness attachments and have a good look at all the welds, netting cable-ties, cage attachments (Velcro, plastic, metal) and finally, on low attachment point machines, the torque-arm attachment to the chassis. These have been a cause of concern on more than one occasion. There is only one manufacturer that I know of – Parajet – that has implemented a failsafe locking system for this attachment once the cage is in place.

Engine

The prop: Start with the propeller and work your way through to the chassis from there. The propeller should obviously not have any damage, especially on the tips, and it should also be running true in the cage.

With some propeller mounting systems it’s possible to tweak out small discrepancies between the tips. Hold a pencil on a part of the chassis where it will stick out and just touch a prop tip. Spin the prop 180 degrees

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FLOATY AIR Pilots flying circuits in an economy task.

Photo: Harris C

ECONOMY FLYING

By Neil Slinger “TAKE OFF and don’t come down until you run out of fuel…” “Fly as many 2km circuits as you can on five litres of fuel…”

“You’ve gone further than you should have, now get home…”

Most of us haven’t really dealt much with economy because, unlike sticks or navigation, we simply don’t think about it until competition time. A lack of accurate fuel consumption figures for our motor/ glider combo, or fears that we’ll have to battle with thermals and cloud-suck can make it a worrying prospect, but the key to success in an economy task lies in our ability to make best use of the air itself, and in optimising our efficiency. In turn this helps us be better allround pilots, and gives us more confidence to explore when flying cross-country.

prop tip. If it is curved-out it generates less parasitic drag at the tip in the form of vortices, which is why modern airliners have wingtip extensions. Playing with reduction drive ratios and using more than two blades can increase efficiency, but are beyond the scope of your average pilot’s weekend tinkerings.

The cage and pilot

A leaner-running engine uses less fuel per piston stroke, but it also creates more heat and you run the risk of burning a hole in the piston top or seizing the engine as the lubricating element of the two-stroke petrol/ oil mix struggles to cope. Using less oil in the two-stroke mix can put more fuel in the tank (ie less oil, more petrol litre for litre) but the engine may seize if the mixture is outside the manufacturer’s recommended tolerance, so tweak carefully.

Reducing weight and drag increases efficiency. The lighter you are and the smoother your profile is the better. Tucking your elbows in and pointing your feet out in front can reduce your drag profile, while a flight deck angled slightly on the knees acts as an aerodynamic down-force like a spoiler on a sports car, adding ‘weight’. Listen to your vario while adjusting your sitting position to demonstrate this.

Aerodynamic profiles on cage tubing, netting cord thickness and riser/webbing widths all affect ‘form drag’. The drag from a strobe light system mounted on a cage may use a tenth of a litre more fuel per hour, but this is minimal compared to the effects of weight. Shave excess weight by wearing lighter clothing and footwear. Petrol weighs 720 grammes per litre, so where fuel is unlimited, learn how little fuel you can get away with for a task.

The propeller

The glider

Tweaking the engine

There are various claims about propellers producing more or less efficient thrust per rotation depending on the shape of the

Unsheathed lines and glider size do influence economy, but trim settings are more important. The ‘minimum sink’ setting is

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FUELLED-UP Michel Carnet’s comp fuel bottle.

Photo: Francis Valdez

the most efficient. It will be at the slower end of the range, but not necessarily as far as ‘full-slow’, so consult your manual.

A small glider with a heavy pilot is not efficient for economy, but is fast for distance and speed. A small pilot with a big glider is good for economy but bad for cruising and getting anywhere quickly, or combating headwind. Competition rules dictate that the same glider or its equivalent replacement (if damage occurs) must be used for all tasks, so you have to choose the best compromise.

Competition gliders have partially unsheathed lines to improve the drag profile, slim aerofoil sections and a high aspect ratio for glide and speed. However, it’s not entirely straightforward: A 31m2 glider may be faster than a 29, for example, due to the way aerodynamics work in various scenarios.

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Preparing for competition

In an economy task pilots are either issued with a limited amount of fuel, or are sent up with as much fuel as they want, but it’s weighed before take-off and after landing.

The weighing technique – fairly complex and laborious – while requiring marshals and weighing scales does open up a few more task options and reduces the risk of mass land-outs which can delay the start of the next task on a good day.

In both cases distances or times are confirmed by GPS and scored according to the task mandate.

Using a comp fuel bottle

Most serious competitors have a competition bottle to monitor fuel levels during a task.

Usually a litre in volume, it is attached to

CUT IT OUT Covering the air intake on the airbox, and flooding the engine with the primer bulb. Photos: Marcus King

KILLING THE MOTOR

By Marcus King COMING in to land one day you go to kill the motor but find yourself with a problem – it just keeps purring away behind your back. What should you do?

Pascal Campbell-Jones offers sound advice: “Don’t panic! Land normally, just remember not to squeeze on any throttle as you flare. Once safely on the ground you can then deal with the problem.”

Mathieu Rouanet echoes this advice, adding that if you don’t have a clutched motor you should be careful of the lines getting tangled in the prop. “If your glider sometimes takes a while to stall and fall

back,” he says, “then you should maybe think of using no brakes and letting it fly over your head while at the same time taking a few steps backwards. This way all the lines will be in front of you.”

On the ground

Once you are safely on the ground you can think about killing the motor safely.

A petrol engine requires three basic ingredients to function: petrol, air and electricity. Withholding the supply of any of them will stop your engine.

The key thing is to have a plan of options

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KILL IT Hand over the exhaust (hot, wear gloves), and interrupting fuel flow on a membrane carb.

YOUR OPTIONS

• Turn off main ignition switch if you have one • If you have a remote choke, pull it on and apply throttle • I f you can reach the air intake safely, cover it with your hand • I f you have a primer bulb pump it to flood the engine • C over the end of the exhaust. Do not attempt this if the prop is spinning • P ress the pin on the membrane of the carb • K ink fuel lines and / or close fuel-tank breather • P ull off spark-plug cap. Be very careful of getting electrocuted et it run out of fuel • L

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for achieving this. When my kill-switch failed I had to try several methods before I found one that worked. If you have an experienced pilot nearby you can ask them for help, but avoid asking unqualified bystanders – it’s all too easy for an inexperienced person to get injured.

Switch it off

If your motor has a master ignition switch, think yourself very lucky and switch it off.

Generally it is only machines with electric starters that have this, although some pullstart units do have one as an extra safety feature.

Dieseling and choke

Failing that, the first thing to try is applying some throttle with the kill-switch pressed.

FLOAT CARB Popular in paramotoring.

Photo: Marcus King

THE CARBURETTOR

By Thomas Keller and Sascha Burkhardt ALL combustion engines require two vital ingredients: air and fuel. These are normally mixed in a carburettor. The precise ratio of fuel-to-air is what makes the difference between an engine running sweetly and one spluttering and coughing away.

Mixing chamber

The carb acts as a mixing chamber for the fuel and air and sits between the piston and barrel and the filtered air intake. ‘Run lean’, with too little fuel and too much air, the engine runs badly, overheats and will probably be damaged. ‘Run rich’, with too

much fuel and not enough air, and the engine floods and most likely won’t even run, or at best does so badly wasting fuel.

Fuel is delivered through jet valves into the mixing chamber. There are two different jets, which come into use at different stages – one delivers fuel when the engine is revving or operating with an open throttle, and one for when the throttle is closed and the engine idling. Screw valves control the amount of fuel delivered through each jet.

Pressure chamber

When the engine is revving, the down-

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Throttle cover and cable connector

Valve spring Needle

Valve

Atomiser Wired choke

Starter knob

Idle screw

Main jet (R) & Slow jet (L)

Air screw

Gasket

Float IN BITS Carburettor close up.

Photo: Polini

stroke of the piston draws the air into the main barrel of the chamber where is it squeezed through a narrow opening, called a Venturi, which accelerates the airflow. As the air flows through this venturi it speeds up causing low pressure, a process known as Bernoulli’s Principle. This low pressure causes fuel to be sucked into the airflow through the open throttle fuel circuit and main jets, which are small holes in the side of the mixing chamber itself.

The amount of air flowing through the chamber is regulated by the throttle valve.

When the engine is idling there isn’t enough

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Cover

Floating Needle QUARTER TURN Adjusting a membrane carb.

Photo: Marcus King

airflow for Bernoulli’s Principle to have any effect, so it doesn’t form the low pressure needed to draw the fuel in. However, because the throttle is closed, a different low pressure sets up behind the throttle valve and the down-stroke of the piston is still able to draw in enough fuel to run the engine. The fuel is delivered through the idle circuit and the idle jets, which are positioned behind the throttle valve.

Out in the cold

When the engine is cold the fuel vapourises less easily and can condense on the

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ď‚ SPARK Small, but powerful.

Photo: Francis Cormon

THE SPARK PLUG

By Dean Eldridge THERE are many components in our paramotoring equipment that are fundamental to our fun and enjoyment.

Possibly none is more important, misunderstood and overlooked than the spark plug.

Spark plug basics

A spark plug is composed of a shell, insulator and the central conductor. It is threaded through the cylinder head and therefore must also seal the combustion chamber against high pressures and temperatures without deteriorating, over

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long periods of time and extended use.

Most spark plugs seal to the cylinder head with a hollow metal washer. This sealing ring is crushed slightly between the flat surface of the head and that of the plug, just above the threads. (A general rule of thumb: to tighten a plug with a sealing ring, turn it finger-tight then a quarter to half-a-turn extra.)

The primary function of the spark plug is to provide a path and a location for electrical energy from the ignition coil to ignite the air/fuel mixture within the combustion chamber under all

RPM ranges and operating conditions.

A sufficient amount of voltage must be supplied by the ignition system to spark across the spark plug gap. This is called the ‘electrical performance’. The gap must therefore be set to the manufacturer’s setting.

A gap that is too small means the spark duration will be too short resulting in a thin and weak spark. This can lead to a loss of performance and an increase in fuel consumption. If the gap is set too large, the ignition system will struggle to cope with the demands and a misfire situation and subsequent engine malfunction can occur. Neither option is good.

NGK spark plugs stripped down

There are many manufacturers of spark plugs including Champion and Denso, but the most commonly used brand for paramotors is NGK. All other plugs operate in the same way and have similar construction.

To explain the code or symbol on the NGK plug consider the common B10ES model: B: 14mm thread, 10: Heat range (cold plug for higher temperatures) E: Thread reach (into the cylinder head) 19mm S: Standard copper core electrode Variations on these that are of interest include a lower number for a hotter plug, an ‘H’ instead of the ‘E’ for shorter thread reach, a ‘G’ or ‘IX’ at the end instead of the ‘S’ for different electrode types and an ‘R’ inserted (eg BR10ES) as the second symbol to denote the addition of a 5kohm resistor.

Resistor spark plugs reduce electromagnetic interference with on-board electronics. They are recommended for paramotor pilots who have systems such as radios, GPS systems and alti/varios on board.

Heat ranges

All of the above is fairly self-explanatory apart from maybe the heat range, which is very important. The spark-plug firingend temperature must be kept low enough to prevent pre-ignition, but high enough to prevent fouling. This is called ‘thermal performance’, and is determined by the heat range selected. The heat range of a spark plug is the range in which the plug works well thermally and is indicated by a number: lower numbers indicate a hotter type (needs lower temperature to reach optimum thermal performance); higher numbers indicate a colder type (requires higher temperature to reach optimum thermal performance).

In most paramotor engines, especially two-strokes, due to the constant high engine RPMs and therefore high temperatures created, we usually find colder-rated spark plugs, ie: those that need higher temperatures to get hot. The above mentioned NGK B10ES is a good example.

Be aware that putting a colder-rated spark plug in your engine will not make it run colder, but a hotter-rated one will definitely raise the temperature!

‘Reading’ the spark plug

For any engine, but especially a two-stroke, having a fresh spark plug is incredibly important, so you should check your plug often. Spark plugs are a window into the engine, and a valuable diagnostic tool.

PLUGS AT HIGH ALTITUDE

Air and cylinder pressures decrease as altitude increases. As a result, spark-plug tip temperature will also decrease. Fouling can occur more easily if the air-fuel mixture is not adjusted to compensate for extended altitude flying.

Higher altitude = thinner air = less fuel required

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THE PERFECT MIX Fuel (red) and air (blue) mix in the carburettor.

Photo: Parajet

UNDERSTANDING THE FUEL SYSTEM

By Dean Eldridge AFTER carefully storing your paramotor in the shed during the winter, it’s fine to just throw some fresh fuel and oil in and go for a blast right? Well, not really. A cold and damp winter layoff can play havoc with your prized possession.

This means that at the start of the season, as well as your routine pre-flight checks, it’s a good idea to spare a thought for all the components that make up the fuel system. This will help pre-empt any possible problems once you get in the air again.

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Coming out of hibernation

Storing your paramotor devoid of fuel is a good start. But all those components that make up the fuel system (from the tank pickup to the reed valves) could have had a hard time in those frigid months.

All these components contain at least a bit of silicon, plastic or rubber that can deteriorate, stretch, shrink and harden with extreme cold and damp conditions.

If you are suffering some poor starting, erratic running, irregular idling and engine

cutouts after machine storage then you might want to take a close look at some of the fuel-system components. Basically, these comprise fuel hose, priming bulb, filters and carburettor/pump. (Unless you are running a competition bottle, a fourstroke or a motor with the tank above the engine, the pumping will be a function of the carburettor.)

Your fuel system

In very simplistic terms, your fuel is sucked from the bottom of the fuel tank, through the fuel hose (that may or may not contain a priming bulb and filters) to the carburettor.

Here it is metered and passed in an exact quantity into the air passing through the central Venturi of the carburettor.

Any variability in the quantity of fuel, or demand from the carburettor to get the fuel or indeed air in the fuel can have a detrimental effect on the smooth running of your motor. Every part of the fuel system has the possibility of creating poor engine performance if not properly checked, maintained and serviced regularly.

Fittings and attachments

A length of fuel hose that appears OK visually may harbour a small hole or slit hiding beneath an over-tightened fitting or clamp. Jubilee clips are notorious for doing this, as well as wire ‘butterfly’ crimps.

As the fuel hose can harden over time and in cold weather, vibrations from a motor can cause the fittings to tear small holes, resulting in air being dragged in, but not necessarily allowing fuel to leak out. Cable ties are better for securing fuel hose to fittings, but not as good as proper hose clamps that ‘wrap’ the hose without pinching.

Fuel hose

It’s best to make sure you have the highest quality fuel hose available: clear, not black,

for detecting air bubbles, especially near the carburettor. Tygon or kart-racing hose is great, but make sure it has the correct internal diameter for its intended application.

Overstretching a small I/D fuel hose onto a large priming bulb fitting, for example, can weaken the hose wall and possibly cause problems. Some cheaper hose (especially from garden machinery suppliers) is liable to harden after a short time.

Priming bulbs

Priming bulbs are used mainly on pullstart machines to purge the fuel system of air before attempting to start them (saving a hefty amount of sweat, tears, swearing and tool throwing). They are also an area of concern. There are many cheap versions on the market that don’t work at all on a paramotor. As soon as the engine has started, they can suck air in with the fuel where the fitting locates into the bulb, causing all sorts of headaches.

They also have a ‘one-way-ball-valve’ in them, which only works correctly at the best of times. In dire cases, they allow the fuel to drag itself back down through the bulb at low revs. The best units seem to be from boat chandleries (Quicksilver brand) and also those used in some diesel cars. Do not buy ones that have a very plastic feel to the bulb, it should feel rubbery.

Breather pipe option

Some folks opt to simplify their fuel system by doing away with the priming bulb altogether. They rely instead, on pressurising the fuel tank (for purging the air and priming the carburettor) by blowing down the fuel-tank vent tube.

This is all well and good so long as you are mindful of the amount of moisture it’s possible to blow down, along with pieces of cookies, cakes, crisps and other gastronomic delights that might end up in the bottom of your tank!

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THE AUTHOR DEAN ELDRIDGE was born in Southampton, England in 1965. He started flying in 1995 when he took up paragliding in Colorado, USA and flew in France, Italy, Greece, Spain, Morocco, Switzerland and Austria before returning home to the UK. With no access to good free-flying sites, in September 2006 Dean took up paramotoring. Pretty soon he’d swapped his day job for fulltime work as a trainee instructor.

A year later he was deeply involved in redrawing the UK syllabus for PPG training and was setting up his own flying school, Paraviation. He has been chief flying instructor ever since.

A founding member of the Parabatix display team he has also excelled in classic

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ď‚ DEAN ELDRIDGE Photo: Sophie Bolesworth

competition, winning Best Newcomer at the British Nationals in 2009 and lifting the trophy and the title of British Paramotor Champion in 2012.

That year Dean also found time to set world records for speed, clocking 73.84km/h over a 25km course at the Salton Sea fly-in in California.

Most recently he has been heavily involved in filming projects, using his paramotor and flying skills to provide a unique perspective for TV production companies around the world, from Brazil to Burma.

A consultant for several paramotoring manufacturers, when not teaching in Europe or filming in an exotic destination, he can be found at home in the relative peace and quiet of the southwest of England.

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