Interested in slope soaring eh? Let me warn you at the outset that although at times you may find it extremely frustrating, the sport will bite hard with a grip that you can not, nor would not, want to shake off.

The ’Lotus Eaters’ are alive and well and thriving on our hills, with a euphoria akin to the surfer who has found the ’perfect wave’. The subject can be dominating to the exclusion of wife, kids, house and job but after the ’honeymoon period’ emerges as a psychologically well balanced, healthy, rational, methodical, caring individual, with an inward satisfaction which a Zen Buddhist would recognise and admire (who am I kidding?). Slope soarers are without doubt, devout in their worship. They will undertake a lengthy round trip or diversion to inspect possible sites. Holidays are never taken except within reach of hilly country, and if forced elsewhere, will spend hours watching the gulls and mentally twiddling the sticks. If you are still with me and are even vaguely curious, read on. In the series of articles, which follow, it is intended to present the hows and whys, the do’s and don’ts which will take you from a clueless novice to a proficient aerobatic pilot. Maybe I have more confidence in your ability than you have, but it won’t cost you a fortune to find out that I was in fact right all along. I am not proposing to teach you how a glider flies; you don’t need to know if you do what we tell you. All you really need is the basic knowledge that if the air is going up faster than the model is coming down, you have extended flight. Right?

Here, we remind you of Gardiner’s first law of soaring; ‘If it’s in lift, it will go up, if not, it will come down’.

Slope lift is the most basic variety of lift generation, and its availability most predictable, providing the wind is blowing of course.

Any hill or ridge facing an oncoming wind will generate some lift as the mass of air approaching has to be diverted up and over. Figure 1 shows a typical scarp slope. Area (a) indicates maximum wind speed and an imaginary line at (say) 60^o – area (b) shows the area of best lift. At (c), the air can in ’fact spill round the side and no lift will be generated. At (d), the wind speed has dropped and with it the lift, this is in fact the area where we start to practice landings. If the site is a spine ridge, you will find ’sink’ or ’curl-over’ on the other side so the down wind area initially must be treated with caution.

You will find that even comparatively low ridges will give useable lift particularly if they are longish and have smooth air, square on. I guess there are many sites that regular slopers drive past looking for somewhere different to fly. In practice, a ridge between 100ft. and 250ft. gives all the lift we need, more is better, less not impossible but try it and see. So, what to fly? Initially your model should have a low flying speed or at least the ability to fly slowly without stalling. By altering the elevator trim, the model should be able to be speeded up or slowed down; you have more time to correct if the air speed is less. ! Remember, however, that with a glider, the control surfaces are only effective if a positive forward speed is maintained so for now everything will have to be a compromise.

Most people learn to fly slope on’ Rudder/Elevator machines, though I see no reason why one should not begin with an Aileron/Elevator model, except that such machines mostly fly too quickly for a beginner. Right, so rudder/elevator it is but which one? There are numerous designs in the RCM&E, Plans Service or your local dealer can usually be trusted to sell you a suitable kit, but it is worth remembering that you can pick up a ready built, serviceable, perhaps well worn model for a few quid. Side benefits are that a second hand machine will have had the bugs ironed out, and you may even receive some help and tuition from the vendor. Your task over the next four weeks is to sort yourself a suitable model, something substantial with an all-up wing loading of between eight and 11 oz. per sq. ft. Check center of gravity position, incidence angles, control movements, etc., and we’ll take it up next month. Future articles will steer you through from competitions and the sort of challenge you should enjoy as you improve. From there you may progress to pylon, aerobatic, cross- country or scale, either way the possibilities are endless.

By now you should have fixed yourself up with a suitable model and will almost certainly have paid at least one tentative visit to the slope to watch the lads performing.

You will no doubt have seen all grades of models and pilots, conversation with whom should have fired your enthusiasm.

So what did you get? A simple two-channel rudder/elevator model? With the radio gear installed, the wing loading should be between 8 and 11 oz. per sq. ft. If it is much less, either the model is too flimsy or you've forgotten the Ni-Cad pack. If it is more than 11 oz. Per sq. ft., you will need a stronger wind and the model will be flying too quickly for a beginner, but don't despair.

Hopefully, you have the original drawings and the balance point under the wings is right. Should it be too far back, add lead inside the nose to correct, alternatively, too far forward, move the receiver or batteries rearwards. Whatever you do, get it right though 1 should add that a little further forward than specified will initially make the model less twitchy to fly. Verify that your incidence angles are as shown, and ensure that your flying surfaces are free of warps. The wings and tail plane should be positively attached to the fuselage so that they do not shift in flight. If using rubber bands however, remember that they can damage the wing in an awkward landing so use ply reinforcements and sufficient bands to ensure rigidity, no more. Now look on the front of the model and check that the wing, tail plane and rudder are not out of line.

Control movements will be as recommended but in practice, about 30^o each side for rudder and 10^o up and down for the elevator should suffice. If your transmitter is two stick, two channel, it is normal to use elevator on the left-back for up, forward for down. Rudder right for right, left for left as in Fig. 1. Should your transmitter be four channel, you must still use the right stick (primary control) for rudder, but you have the option of right or left sticks for elevator, the choice is yours and eventually you will use either. I do however, strongly recommend that you start with two sticks, as your eventual aerobatics will progress the better, you will see why in due course. Your trims should be in the centre position with the incidence angles correct. Now go through it all again.

So, your Ni-Cads are charged and you're ready to go.  Hold it, have you done a range cheek on the radio? With the aerial collapsed, you should have solid control at a distance of 5 to 75 yards (as specified by the manufacturer). Right? Grab your warm clothing and you can go, but at this stage, be absolutely sure that you know your control movements as we are about to commit time, money and effort. Remember that it's 'right for right', away from you but reversed coming towards you. Therefore mentally project yourself into the model and, eliminate the need to think which way the stick goes. Up and down elevator don't change of course (until you fly inverted, but that comes later).

Now you're on the hill, the wind is square on and you've checked your frequency is clear. Wind strength? If it feels 'fresh' it's right, if you (a) can't feel a wind or (b) can't stand up - go home again.

OK, here we go. Switch on. Aerial out and hold your model up into wind. It should feel buoyant and a firm downwards launch should get your model away.

Be prepared to feed in down elevator to increase speed if the machine will not penetrate and adjust your trim such that the model moves forward whilst steadily gaining height. When learning, always make your turns away from the slope and remember the tendency is always to over-control. Make your first rudder movements as a series of 'nudges' in the required direction and you will soon estimate the amount required for smooth control. Right so its out and its up, your trim is adjusted, what we need to do now is tack up and down the ridge. 'Nudge' your rudder and see what happens, more, and your model should be heading sideways across the slope. Now nudge, the other way and make a 180^o turn so it heads back, adjusting elevator as necessary. Practice this until your pulse rate goes down and we'll try a landing. Your model must be landed in the area of sink behind the slope and here patience will be rewarded. Let each progressive pass along the ridge drift further and further back until you lose the obvious lift. At this stage the model should be behind you, turn around and you will make your turn back into wind without thinking .  Feed in enough down elevator to prevent it drifting back and hold it. Do it right, and the model should slide to rest at your feet. If you had too much height, fly out into the lift and start again.

Remember what I said about control surfaces and flying speed? As you become proficient, you will realise that you can increase speed by applying down elevator control or trim, and your model will become more responsive. At any time, you can swap speed for height, so practice flying a little more adventurously. Keep it moving and have fun.

When you can fly the model quickly and have no orientation problems, try the simple straight in landing. This involves a downwind leg that needs plenty of speed, so be positive. From a cross wind tack, feed in down and fly the model through a 2700 turn until it is heading back into wind, with a comparatively slow ground speed. Remember the model will be travelling quickly on the down wind leg and could cover a lot of ground so do it all in one movement. When practicing landings do both right and left hand approaches.

Next we'll try basic aerobatics for rudder/elevator and look at our selection of an aerobatic model.

By now your geography and meteorology have improved, you know what 5-minute epoxy is for, and have a wider circle of friends. If you are feeling more confident in your flying ability, and remembering also that speed means effective control surfaces and directional stability, try these:

1. Loops. Head straight out into wind. Well up and well out and check your orientation. Here goes - down elevator for a progressively steepening dive. When the model is flying quickly, ease in and hold 'up' elevator. If the speed is sufficient, the model will fly over the top and down gaining speed on the descent. Hold on the 'up' as the model passes the bottom of the loop then feed in a touch of 'down' to prevent ballooning up. Aim for a smooth transition back to level flight.

2. Continuous Loops. As above but case off the 'up' on the downward part to build up more speed, then 'up' into the next loop. You will appreciate that continuous loops are really elliptical in shape so be prepared to resume level flight before you drop out of lift or hit the deck! When you feel up to it, try loops across wind, use rudder if necessary to prevent rolling out. Remember, speed makes it easier.

3. Stall. You will have been trying to prevent a stall, now induce one. Head into wind and progressively ease in 'up' elevator. You will see the nose rise and flying speed drop until the model fails off to one side and drops nose down. At this point, control can only be regained by pushing in 'down' elevator and consciously diving to re-establish flying speed. Only when the speed has built up can you case in 'up' elevator to regain level flight.

4. Stall Turn. Fig. 1 a. Do this across wind. Dive for speed, ease in 'up' until the model is climbing at an angle of say 45⁰ and neutralise elevator. Now, just before the model stalls, apply full rudder away from the slope and your model should turn in its own length to face down. Centralise rudder and dive for speed to regain control.

5. Double Stall Turn. Fig. 1 b. Following you dive from the stall turn, case in 'up' for the climb and apply rudder the opposite way i.e. still away from the slope, just before the stall point is reached. Properly done, this is a neat 'Vee' with both sides the some length and square on to wind - keep trying.

6. Spins. Plenty of height, well out, head into wind pull and hold up elevator. As the model stalls. apply and hold full rudder, right or left. The model will perform a rapid banked turn followed by a spiral descent - actually in stalled condition, so down elevator an opposite rudder will be required to regal control.

7. Pylon Race Turns. You won't win an races, but fly the model along the slope at eye level. You will need down elevator to proven height gain, do it and watch the speed bull up. At your 'tacking' point, apply rudder away from the slope and as the model starts to roll, neutralise the rudder pulling in 'up' elevator and return when the model is heading back Repeat each end, always away from the slope.

It is possible to perform inverted flight, roll and bunts with some R/E models, but they d not yet form part of this programme. When you have mastered the foregoing and can take the model home in one piece, you are ready for the next stage.

We need ailerons and elevator only on the next sloper. If a rudder is fitted, tape it up and disconnect the servo for the time being - it' a complication we don't need just yet.

Aileron is now the primary control - replacing rudder on the right hand stick. ‘Right' moves the right hand aileron up, the left one down and vice verse. Elevator on the left hand stick means that vertical and rolling movements can be done without interaction, you will come to appreciate this in due course. You will in fact be able to perform most manoeuvres in 'the book’s lying two channel only and if your first aileron model is not fitted with a rudder, don't worry, as it will be some time before you will need it. Having confirmed this point, be aware that the cheap' 27MHz gear available is still adequate for slope soarers, as we don't fly at great distances as Thermal soarers do, so you should not suffer from illegal CB interference. In any case keep off Blue and the Splits and you'll be safer.

What to fly? Look for a conventional model about 60in. span, no dihedral, asymmetrical section (E374 is good), strip ailerons and substantial construction. Again, your choice of plan or kit is complemented by the possibility of a good 'second-hand' buy.

Have a chat with the lads on the slope or your friendly neighbourhood dealer. In due course we'll get round to a review of full house aerobatic soarers on the market, but for the moment, one is as good as another. In choosing a ready-built, do check for crash damage as some repairs can make a model unsatisfactory. Refer to the checklist regarding centre of gravity, incidence angles, slop-free linkages that do not bind, etc. and we'll be ready for next month.

Meanwhile, you may consider the sort of simple competitions to test your growing skills. Set yourself a target time from launch to landing - say 3 minutes, deduct one point per second over or under for a maximum score of 180. Your timekeeper will count you down. You can aim to land as close as possible to a spot marked out beforehand out of lift of course. Score 30 points within one pace; deduct one point per pace away to a maximum of 30. Then combine time and spot for a maximum score of 210. Got it?

Lots of fun can be had from the loops competition. Aim to loop as many times as possible within say 3 minutes, one point per loop - i.e., rolls and stalled or part-loops do not score. Stop counting loops at the end of time end start deducting one point every 10 seconds over 3 minutes before landing.

All good fun and practice for your aerobatic debut next month - go get yourself a model

By this time you are hardly new to the slope, but we'll keep the same heading anyway.

If you have visited the slopes, you will have seen aerobatic machines and soarers of all types, so you should have had little difficulty In deciding which model to build or acquire. Just to recap; two channel, aileron elevator for the next stage. All checked out and ready to go? Great.

Session 3's offerings included the' Pylon race turn' for rudder/elevator models and this is really the key to aileron/elevator flying. You will be aware that a rudder/elevator model with dihedral can be made to circle on rudder only. Application of rudder causes a yaw which produces offset lift/drag and a consequent banked turn which is neutralised by centralising the rudder. You will remember that the pylon race turn was a combination of the two controls, but with one extra ingredient, speed. We were driving the model at eye level along the slope with a little down elevator to prevent height gain, but this produced an increase in speed as we were in effect diving through the lift. Sudden application of rudder produces a tendency to roll, and in a banked position, the rudder then becomes 'down' elevator so the rudder was neutralised and 1 up' elevator fed in as the elevator now becomes the rudder. Centralise controls as your new heading is reached and you've done it. Easy?

Right, its aileron/elevator time folks. Treat every turn as a R/E pylon turn but using aileron to induce a roll. As before, when the necessary angle has been reached, centralise ailerons and apply ‘up' elevator hold until your turn is complete and centralise but note one addition. A dihedral R/E model will 'pendulum' back to level flight but an aileron model requires the application of a little opposite aileron until the wing5 are level again. Practice mentally until you are confident you'll get it right.

1 should mention of course, that your first aileron/elevator turns will not be at eye level but with as much height as you can gain. Also, remember it is no disgrace to let an experienced pilot fly the model first to check it out and gain some height before handing over. You will have even more confidence if he shows that the model is capable of a few aerobatics, but just as important, watch the landing.

Right, it's your turn and though you may choose to take over from an experienced pilot with some height on, I'll presume you are confident enough to start from the launch. (if you've played Space Invaders', this is easy).

Wind right checked frequency clear? Switched on? Controls neutral and working the right way? Now for it. A firm, slightly downward launch will get the model. away and give you a couple of seconds to feed in whatever corrections are necessity to get the model moving upwards and outwards away from the slope. Head straight out for effective height gain. i.e., Height above launch point plus height above the slope and prepare for a turn. First feed in a little ‘up' trim to slow the model down. Now, remember the *Nudge, Nudge' technique for not over controlling the rudder/elevator model? Try the same for your ailerons. A small movement and return should change the direction without touching the elevator control. OK, right, right, right. left, left, left. -See what happened? The momentary bank produces a sideslip which changed the heading and with a touch of 'up' trim to slow the model down, the turn came automatically. Try it always away from the slope - until you get the hang of it, then try tacking up and down the ridge making a 180^o turn each end.

By now you should have plenty of height, so adjust for more speed by feeding in a touch of down trim, but beware that your aileron control will become more effective and the roll more positive. Be prepared to neutralise ailerons, apply up elevator, neutralise and apply opposite ailerons to regain straight and level. See sketch below. With your R/E experience, elevator response should be automatic but keep your stick movements gentle until you are sure you are in command.

So far you have made your turns into wind and away from the slope so we'll try a large circle. Remember the tendency to drift back towards the hill so position well out, and fly parallel to the ridge; speed helps. Aileron to bank, centralise and ease in up elevator to keep the model going round and as it reaches the mid point, ease off with a touch of opposite aileron to straighten up. Practice right and left then put some height and distance on because we are coming to the exciting bit ...

Start your full circle, but only do 270^o before carrying out the correction technique normally done at completion of the circle. The model is now coming towards you. Now what? Joe Cool eases in opposite aileron and ~up elevator to begin a circle the other way. 'Hold the elevator until the model is heading forward into wind again and centralise before patting yourself on the back.

Build up your orientation skills by practicing turns towards and away from you until your aileron and elevator coordination is automatic. Do not attempt aerobatics until you are sure of this, as things happen very quickly and it would be a shame to wreck the model at this stage.

A worthwhile tip. If you do find yourself in trouble, pull ‘up' elevator. From upright or inverted, this puts the model into a loop, if 'you are banked it will be a circle and you should have time to see which way it is going before your next move which will almost always be a shallow dive for flying speed. If you are too low to start with, hard luck, you should be up and out, eh?

No, we won't leave you up there until the next section., your landings should if anything be easier with A/E than R/E as you have more precise control on the approach. Fly the model towards you along the slope doing left and right turns Fig. 2. If you are in doubt, bank and turn back into lift. By practising turns towards yourself, you will come to correct any tendency to drop a wing on the approach for landing which will be behind the slope, out of lift and heading into wind so that ground speed is lowest.

Make each approach lower and further downwind until you are sure that the model is out of lift then turn into wind. If the wind speed equals model speed, then it will settler gently but the equaliser is your left stick. Should the model be too high, tack from side to side to lose height, or fly round again. No hurry, but do it right.

Next section we'll get around to a little more advanced stuff, but as you've now got ailerons, we'll try a simple roll.

Height on, up and out. Head into wind and dive for speed, ease in a little 'up' elevator sufficient to induce a fast shallow climb. Bang over the ailerons and hold them on as the model rolls. Be ready to neutralise as soon as the roll is almost completed to regain level flight. The experts feed in ‘down' whilst the model is inverted to stop the nose from dropping but as you started in a shallow climb, you won't have to worry about that yet.

Three things you need; speed, coordination and practice. Keep at it, soon you'll have beginners asking for your advice.

Yippee - you're getting good.

This section covers a selection of basic aerobatics that will look good, give you lots of satisfaction, still only need two channels and set you up for the advanced stuff.

Just a reminder, speed makes everything easier and you can always swap speed for height, so fly with confidence and the precision of a brain surgeon.

1. Loops and straight stall - Exactly the same as for your R/E model.

2 Roll. We put you into it last month from a shallow climb into wind. Now dive for speed as before but try a level entry, feeding in a touch of 'down' elevator as the model rolls past - inverted. This will keep the nose up. Properly done, your model will do a neat axial roll and will finish straight and level on the, same heading.

3 Inverted. Still into wind. Dive for speed. Level out and apply aileron to roll. At the inverted part of the roll you have been touching in 'down' elevator as in 2, but neutralise ailerons to stop the rolling movement and hold in the down. Too much down and your model will stall, not enough and a shallow dive will result. 'Balance' the model on ailerons and fly on elevator. See how long you can hold inverted into wind then relax'. Elevator and roll upright to complete.

An inverted stall can be controlled by adjusting elevator, you will eventually fly inverted without thinking but should you get it badly wrong. half roll and give it 'up.' You will find your model the right way up but it could be travelling in any direction so watch and correct as required.

Most newcomers are pleasantly surprised to find that the aileron controls for left and right turns do not alter when the model is inverted, but it is obvious when you think about it. Yes? Your elevator is of course reversed when inverted and the amount of 'down* to hold on to maintain level flight is only to be discovered by trying. If the model is high enough, you won't develop any ulcers.

4. Inverted turns. From inverted into wind, gently nudge in aileron left and right feeding in a little more down to promote the turn. Don't turn downwind yet, tack left and right but be prepared to roll out if necessary. We'll give you the inverted circle later.

5 Roll off the bottom. You'll love this one. From straight and level across wind with plenty of height, push and hold 'down.' Your model must perform half a bunt (outside loop) but whilst inverted at the bottom, half roll upright letting off down elevator to regain,' level flight,

6. Roll off the top. Across wind, dive for speed, pull and hold 'up' but half roll and neutralise elevator at the top to regain level flight (but in the opposite direction).

7. Loops across the wind. Again. 'up and out' - head across wind and initiate a long' shallow dive for speed before pulling in 'up' for the loop. As before, ease in a touch of ‘down' to prevent ballooning up on completion. Consecutive loops across wind involve easing off the 'up' on the downward part of the loop to build up speed but you may find the model drifting back towards the ridge so be prepared to apply a little aileron (or rudder if you have it) to yaw away from the slope, particularly on the upward half when the model is tending to slow down. Don't overdo it or you will actually find it heading towards you at high speed on the downward sector.

The manoeuvres so far described are the 'building blocks' for most aerobatics. The descriptions and methods may be an over simplification but we are relying on your progression by way of the rudder/elevator mode to form the basis for your own improving technique. Practice these until your co-ordination is automatic. Remember to keep the model moving quickly, this is easy enough in lift and you should not be attempting aerobatics if it is poor. Next, we will look at some manoeuvres which are a little more advanced, but all using the basics you have tackled so far. Co-ordination and practice are the keywords.

As you will know this is a horizontal eight comprised of two loops joined by half rolls. This is a development of the 'roll off the top' except that the half roll begins at about 'ten past' and leads immediately into the next loop which is anti-clockwise as drawn. You can approach from either side, but Ideally, your start, crossover and finish super-imposed with a side. The main thing to remember with a Cuban Eight is that speed must be maintained throughout the first loop as there is little time to regain lost momentum during the half rolling portion of the manoeuvre. Aim to keep your first loop quite wide, as the main reason for loss of speed is too much up elevator and too tight a loop. The wider you make the loop, the more time you will have to execute the half roll and regain the speed lost on the upward section. So initially keep it smooth and fast.

Right, here's how we start. Practice a few fast loops across wind and a couple of 'rolls off the top'. Leave the final half roll as late as you can each time until you can roll at quarter past' and resume level flight. When you are satisfied you can arrive at this point with enough speed, attempt your second loop and half roll out approaching the cross-over point for completion of the manoeuvre. You can of course abort at any time using the usual roll out or up elevator technique. You should not experience any problems if you have progressed with me this far,

If your model is correctly set up with any inherent tendency to turn trimmed out, you should not have problems performing square on to the wind, but you will appreciate that if you roll more or less than 180^o, your second loop will begin with the model pointing towards or away from the slope.

There you have the basic Cuban Eight. Only practice will show how tight your loops can or should be made for style or continuity, as it should be possible to do consecutive Cuban Flights once the technique has been mastered. Practice this basic version and we will polish it up in due course.

If you are not sure of your model's ability to perform an outside loop, you will appreciate the 'roll off the bottom' we introduced last month. Until you gain experience, there is no substitute for height and speed, so push well out for effective height gain for your first attempt, which we will do across wind. Practice your 'roll off the bottom' leaving the half roll out later each time. This means that if you find yourself on the upwards side of the bunt with insufficient speed, you will have no problems remaining in command.

Now you are satisfied, try it for real. Well up, well out and off to one side. Then start a long shallow dive for speed before pushing the stick forward for your manoeuvre. Again, be warned that too much down elevator produces too tight a bunt which kills flying speed instantly and makes a stalled exit almost certain. Fly your outside loop smoothly with as much speed as you can maintain and hold in 'down' until the model has passed the 12 o'clock position. If you have enough speed on, you may feed in a little more down as the model approaches the top. Ideally you should finish with the same height with no deviation across wind.

By now you will know whether your model can perform a satisfactory outside loop and if you are feeling confident, try one downwind towards yourself.

The fig shows the sequence which for the same reasons make continuous outside loops easier. For your own peace of mind (and the model's safety) start up and out, off to one side and commence a shallow dive building up speed in a banked turn towards yourself. As soon as your model has built up enough speed and is heading towards you, push the stick forward and hold your breath as the model tucks under with plenty of height to spare. At this point you will find the lift is helping to maintain speed and your model should have no trouble continuing the climb over the top. It will then be heading towards the slope and it is essential to roll away to clear the ridge. You can of course abort at any

time except during the second quadrant when you are inverted closest to the hill. Do be careful where you 'chicken-out' but fly with confidence.

By now you will be aware that the half roll is the secret of learning most advanced manoeuvres as they can be attempted one piece at a time in the knowledge that control can be regained at any time should any attempt fail.

If you are able to cope so far, you should have no problems with the next offerings which will include horizontal and vertical eights that are a combination of inside and outside loops. After that, we'll begin to look at the use of the rudder in your slope aerobatic career.

This session we look at the vertical and horizontal eights, which you should find easier than the Cuban eight providing you keep speed up through the whole of the manoeuvre. The Cuban eight is comprised of two loops joined by half rolls whilst the vertical and horizontal eights involve consecutive loops and bunts to describe a figure eight pattern square on to the wind and requires no rolling whatever.

Consider first the vertical eight and ask yourself why one would not commence this manoeuvre at the bottom. The reason obviously is that there would be insufficient impetus to carry the model over the top of the manoeuvre. Starting at the top with a bunt would require one and a half circles and the subsequent loop would finish at the interaction with the model inverted, so that is out. The vertical eight must start at centre with as much speed as possible over the initial loop, as the build-up for the bunt starts from inverted' at the top of the loop, the highest point of the figure.

In practice, gain plenty of height and begin from one side with a long shallow dive and as much speed as possible. Mentally project your vertical eight onto the sky and aim for an intersection-point which will give you ample height to recover if your speed on the bunt be too slow. Aim through the intersection point and pull up into the loop which should not be so tight that speed is lost. At the top and on the downward leg of this loop. consciously ease in the 'up' as this is your only chance to build up speed for the bunt which begins with down elevator at the intersection. Hold down elevator throughout the bunt and aim to complete at the crossover point remembering that an out of balance or out of trim model nay tend to veer to one side, so be prepared to take corrective action. You should have no trouble rolling out of the bunt should you decide to abort, remember height means safety or speed, speed means ability.

The horizontal eight is a development of the same theme except that there is no opportunity to build up speed once the manoeuvre has begun. Thus we must take advantage of the fact that most models will loop better than bunt so our initial dive for speed will be used for the outside loop first with the slower inside loop last. Consider your mental projection and aim your dive for speed to join the first bunt at a tangent at about 45⁰ from the vertical. Hold on down elevator for the first circle and pull up elevator at the cross over point. Hold for the loop. dive out and turn away from the ridge on completion at the centre point.

These are not competition winning presentations but serve as a useful introduction before the final 'polishing up' course which comes later.

Now for another 'basic'. You will remember we showed a simple roll by diving into wind, initiating a fast, shallow climb before banging the ailerons over for a roll. The slight nose-up entry was sufficient to stop the nose dropping during your initial attempts precluding the use of down elevator on the inverted section. You should have mastered the down elevator touch by now and as we are going to attempt a four point roll without a rudder, the knife-edge position cannot be prolonged. Initial attempts can be into wind as your aileron coordination can be assessed more accurately when you see how much roll is obtained from a particular stick movement. Eventually, you will be carrying out the four point roll across wind but for starters, gain height and dive from overhead, lifting the nose into a fast shallow climb as before. Now nudge the aileron stick and neutralise to see its influence on the model, quickly nudging it back to the upright position. Next, assess the amount of movement necessary to roll the model to knife-edge and return. Then start again with a fast shallow climb and nudge and neutralise the ailerons four times in quick succession in the same direction and you will find you have executed something akin to a recognisable four point roll.

Now try it again using a dab of down elevator on the inverted section as with a conventional roll and you will find entry can be made slower without a great loss of height.

Next - if you feel really confident, try it across wind.

We will come back to this one again when you have a model which is rudder equipped, meantime, think about variations. Is a three point roll harder than a four-point roll and who needs a rudder anyway? You will find out in the next part.

The question is "What for?" - The answer, "Not a lot." When you have un-taped your rudder, or coupled up your servo or whatever, you have a control with limited usefulness but one which is essential for those few extra points in an acrobatic comp. On a low aspect ratio sloper, we do not have a need for coupled rudder/aileron turns as is full size practice (particularly high aspect ratio sailplanes) and application of rudder is required in only a few manoeuvres.

Treat this exactly as your first rudder/ elevator model. Dive for speed across wind, nose up and apply rudder away from the slope just before the model stalls. Aim to turn the model back in its own length. A double stall turn is the 'Vee' presentation as described in the Nov. '82 issue. This is not a high scoring manoeuvre and is generally left out of most competitions' schedules.

Here you need height and plenty of it. Head into lift, pull and hold up-elevator and as the model stalls - apply and hold full rudder and full aileron movement in the same direction -i.e. right aileron, right rudder. The model is then in a fully stalled condition and will follow the usual spiral descent pattern. Anticipate the time needed to straighten out and neutralise controls so that the three turns are completed with the model straight and level on the same heading. Right, so you used the rudder to put in a yaw to emphasise the change of direction - now try the same spin procedure again without touching the rudder, would the judges have noticed any difference?

We have tackled the four-point roll using a little elevator to keep the nose up in the inverted quadrant but we now have the ability to apply opposite rudder to maintain a level axis throughout the whole of the roll. The easiest way to coordinate your controls is to practice a 'pattern' and here the aileron right, rudder/elevator left transmitter mode helps. The sketch here shows a sequence for a right hand roll.

Again practice it away from yourself until you see how much effect your stick movements have and practice until your fingers move automatically' You may not need much elevator movement but generally full rudder is necessary to have any effect in keeping the nose up as the fuselage lateral area obviously has restricted effect during this manoeuvre.

Again, if your model is flying fast, the need for 'top rudder' to keep the nose up in knife edge is minimised but the expert judge will always be impressed by a slow four point roll - particularly if this is followed by one in the reverse direction.

There are other manoeuvres which are designed to incorporate correct use of rudder and the three examples given here will set you up for the rest which will be introduced in future issues. Suffice it to say that in these eight articles, you have the basis for all your acrobatic flying and having mastered those, you are unlikely to have further problems with anything the competition organiser asks. Fly with confidence and you will see that the promise made back at the beginning has been kept.

Hope that this has helped, your comments would be appreciated.