Ever wanted to get into or improve your aerobatics?

[Peter Jenkins]

I forgot to add the judging criteria for the two superimposed loops. Here they are:

Two loops

Model pulls up and performs two superimposed loops and recovers in level flight.

Downgrades:

(1) Loops not round

(2) Loops not superimposed

(3) Wings not level during loops.

(4) Changes in heading during loops

Moving on now to dealing with the effect of a cross wind on your manoeuvre.

Let’s say you are flying right to left with the crosswind blowing in your face. You will have used right rudder to set the flight path so the aircraft tracks correctly parallel to the runway but with the nose pointing to the right of track – you will have used rudder to establish this position and then gone back to neutral rudder. There are two techniques to holding the right position.

The first way. As you start your pull up, you need to do two things. Look for the effect of any yaw induced by the increase of power and keep the aircraft tracking straight AND gently squeeze in some right rudder to keep the aircraft tracking correctly in the vertical plane. What you are trying to do is to fly a slightly barrelly loop to prevent the wind blowing the aircraft towards you but so you pull up, you need to introduce this change of direction.

The second way of dealing with this situation is to use a small amount of bank. Using the same conditions as above, as you start your pull up, you introduce a small amount of right bank to start the barrel. You don’t need much and do it smoothly so it doesn’t look obvious. Once you’ve established the bank keep your eye on the flight path and either take some bank off or add a touch more to keep the loop in the right place. As you are coming down on the loop, you need to consider that your wings must appear to be level at both the top and the bottom of the loop so keep that in mind.

Choose which ever technique suits you – both work. An easy way to remember in which direction to apply rudder or bank is that it is always in the direction from which the cross wind component is blowing.

Clearly, when the cross wind component is from behind you then the opposite control movements to the above case are needed.

[Peter Jenkins]

Willy UK - well done mate. I hope you feel the aircraft is much nicer to fly now.

Graeme - I'm surprised that you managed to get through Clubman that fast. Then again, it depends on how big you make your manoeuvres. The brain strain does get a bit less the more you practice. If you have a colleague who can act as your caller and in telling you when you are crossing centre it becomes a little bit easier. They can also be helpful in warning that you are approaching the edge of the box or can call when you should start your end manouevre. You are right about not needed excess weight on board vis a vis battery and fuel. Just remember that as you practice that some flights everything goes well and others not! That's just part of the challenge of flying aerobatics. No two flights are ever the same!

I don't think many folks realise how much effort is needed to string together the 9 aerobatic manoeuvres that comprise the Clubman Schedule. Don't try and fly the whole schedule immediately. Build up to it by doing 2 manoeuvres first and then add a third etc. You will find that if you get out of line in a manoeuvre it causes a problem with your next manoeuvre as you entry point may not be optimal! As I say, take things at an easy pace but keep building up the manoeuvre list as your flying and accuracy improves.

[graeme jones]

Peter - sorry, my mistake. 2 min 30 sec is the time on my Tx but does not include all flying time. Timer is set to run only above 5% throttle, so I can add another 30 to 60 secs for the spin, the down lines and the last leg of the landing. Total flight time therefore between 3 and 3.5 mins. Does that sound more reasonable? Not sure I can make the loops, for example, any bigger without exceeding the vertical 60 degrees or flying further away, in which case I'd need a telescope.

I'm probably missing something obvious, but how is the vertical 60 degrees marked?

And how do the judges decide if loops are round? What looks round to one person will look oval to another. Without something circular as a reference it must be very subjective.

Graeme

[Peter Jenkins]

Hi Graeme

The 60 deg vertical box is not marked it's a judging decision as to whether you are outside the vertical box. 60 deg is a pretty steep angle though. If you have a set square with a 60 deg angle line your eye up with the 60 deg slope while you look at your house roof!

With a 50 size model, Wot 4 etc, you should aim to fly at around 70 metres from you. That is quite a long way out and does give you a pretty fair amount of space both horizontal and vertical in which to operate.

As regards judging a round loop - well, I guess that comes with some experience of judging. By the time you've spent the best part of a day looking at loops you can pretty much judge that the entry and exit heights are the same or not, that they look round as opposed to egg, or some other, shape! Bunts are also fairly easy to judge since most people tend to push too hard on the second half and perform a figure 6 instead. Where it gets really difficult is when you are judging at the top end. As in all sports, there is very little to choose between the top pilots and it comes down to very minor deficiencies. I'd like to say that having a big name doesn't influence the judges but anecdotal feedback from the recent World Champs tended to be that the big names got away with misdemeanours that the unknown pilots didn't! So, yes, judging is subject to some subjectivity but there would be no contests without judges so you have to learn to take the rough with the smooth - just like life!

[graeme jones]

Peter - thanks for that. I've come across the "halo factor" before. Something about judges assuming that top competitors get all the easy bits right. Happens in many sports. I've thought of a way to check how round my loops actually are, using a video camera with the zoom set to give a 60 degree field of view, set on a tripod so that the bottom of the frame is lined up with the horizon i.e. camera tilted up at 30 degrees. Do a few loops, look at the video and try to work out what went wrong! Might be useful for the cuban eight as well. Hope to try it tomorrow.

Graeme

[Peter Jenkins]

Graeme, it's notoriously difficult to judge your own manoeuvres accurately as you are concentrating on flying the bally things. Best to get a club mate who knows a bit about aerobatics to hold up a ring of some sort and view the aircraft's flight path around the rim of the ring. A serviettte ring would do but make sure it's a round one and not one of those flattened ones!

I'll be coming to flying the Cuban 8 shortly but if you are up to that stage already remember that the flight path is what the judges are assessing not the model's attitude. So as the Cuban 8 is started into wind remember that the wind will stretch out the first 45 deg down line so you need to fly a steeper downline to compensate. Conversely, on the second 45 deg downline when you are flying into wind, your ground speed will be reduced and so the actual path will be steeper so you need to fly a shallower downline. This will have the effect of allowing the actual path of the aircraft to be closer to 45 deg on both legs.

Peter

[graeme jones]

Peter - I don't often have the luxury of another pilot to help, but I hope to try that when I'm doing some serious practice later in the year. In the meantime I'm thinking along the lines of a hoola-hoop on a stick. I'll do a bit of maths later to work out how far away it needs to be.

Tried the camera on a tripod. It only half worked. My best camera has a horizontal field of view of around 50 degrees on wide angle, but it's "widescreen", giving a vertical field of view of only 30 degrees. I've got 5 mins of video showing the bottom half of about 20 loops! I'll try it again with the camera some distance behind me and pointed at where I intend the centre of the loops to be. 3 cameras could cover the whole of the "box", giving feedback on the turnarounds as well. Probably not much good for serious competition work but it's good fun to try these things.

Didn't try the rest of the schedule today. It was very windy, the trees, buildings and wind turbines upwind were generating so much turbulence that everyone else packed up and went (or was it something I said?). At least I didn't get a headache.

Graeme

[Martin McIntosh]

Many, many eons ago at a team practice and judging session someone came up with the idea of placing a square frame to represent the box limits in front of the (single) judge. A piece of string was attached and when the end touched the judge`s nose the box was in the right place to give +- 45 and 60 vertical. This really worked well and showed us that most manoeuvres were easily within the vertical plane but we had to fly a fair distance away to get, say, a 5 second roll plus entry and exit of 100m within the box.

[Willyuk]

Well, this ere arereobaticy stuff is too hard. I have been practising ( note I am a bit new to flying, let alone precision stuff) I can see where I am wrong on loops and stall turns, spins are all over the place etc etc but I know practise is the key. BUT slow rolls! I just can't even get close. I can manage a reasonably fast roll say 2 secs with a bit of down ele usually at around the right place, so more practise and I think it will come but trying to slow it down more just causes real troubles. I know the theory and have tried using rudder but it is a mess. SO, anyone have any good ideas of a suitable practise regime, or a way of getting in sync with the sticks?

As for landing in the wind today, nightmare!

thanks gents

[Steve Colman]

Willyuk,

What has really helped me is flying a small, light, EPP foam model. One of those 3D thingies with very tamed down rates. Those brown trouser moments don't cost so much (indeed often nothing).

Of course, a convenient place to fly, plenty of time to practice and decent weather helps too. I'm very lucky in this respect as I work a few hours part time, a field is 5 min walk from the house and I live in Spain. I can go out in the morning with model and four lipos, get in four flights and be back in the house within an hour. Then, depending on my commitments for the day, the lipos can be charged ready for another session usually in the evening.

Of course, it's great to do the above and just have aimless fun flying around. The trick for me was/is to concentrate on one thing per flight. Even something as basic as flying a square or rectangular circuit in both directions for instance, at a constant speed, constant height with the turns in the same spot. And, as has been mentioned many times in this thread, just flying straight and level, do the same inverted, try the circuits inverted and so on.

Of course, I do appreciate that I'm in a very fortunate position re the above and not everyone is as lucky. Also, not everyone takes a shine to small foam models. But, for me they have been instrumental in the slow but gradual improvement of my flying skills.

Steve.

[Peter Jenkins]

Willy UK - I'm assuming that you have got your CG in the right place as I described much earlier on. If you have the CG too far forward, rolling is much more of a chore! Assuming the CG is right, a useful trick to learning to do the 2 rolls is to start with a 45 deg climb and sufficient power to maintain your level speed. That removes the fear of hitting the ground as even if you make a hash of the first roll you are probably only flying level and at a significantly greater height than when you started the rolls.

As you get more proficient in rolling, bring the angle down gradually till you are flying level. I found that helped me to overcome my fear and therefore the clumsy use of the controls.

I was flying in today's winds and managed 2 cross wind landings with one with a gentle tap on the ground with a wing tip and the second one fine. I assume you were also landing cross wind in which case the thing to remember as you squeeze in rudder (away from the direction from which the wind is blowing) is to squeeze in some opposite aileron to keep the wings level.

These are viable alternatives to Steve's use of foamies since today was not a viable day for foamies!

Can you be a bit more precise about your spin problems? Is it the recovery to the same direction as entry or getting into the spin?

Peter

[Martin McIntosh]

Willyuk, Are you trying to do slow rolls without having first mastered the four point?

When I started in this game I did four points a little at a time. Do a quarter roll and by adding rudder try to keep it there for a second or two. This will show if your model is set up and trimmed correctly. Then roll to inverted and hold it there. Now try rolling in the opposite direction and hold knife edge again. After much practice you should be able to string this together and apply the correct amount of rudder each time. Use loads of expo on rudder and it will become much less critical.

The slow roll is just a progression of this but with a smoother transition between quarters. Being an old git I fly mode 1 which means that I can just hold the aileron stick over and move the left rudder/elevator stick in a rough sort of circle, keeping the roll rate constant. Eight points are probably the most difficult because the rudder needs to be controlled in definite steps but I can, and do, flick the ailerons for each point, allowing the stick to return to centre with my thumb off. Not possible if you fly mode 2 because you still need to control elevator.

The manoeuvre to really test you and get you used to putting in the correct rudder is the reverse point roll. Three points one way then three points back. Then start again rolling the opposite way.

Best of luck.

[Willyuk]

Thanks for the input all, I am trying the rolls at about a 30 degree upward trajectory so hopefully not too much fear of the ground. As for the spin, I have hardly tried this before so it is just practise. At the moment it is very random as to if it spins, and when. In my defence I have only flown this particular aircraft a few times and it was put together as a cheap practise hack. I hope after a few more flights to have learned its characteristics a bit more.

ha ha ha - reverse point roll I think someone is having a laugh. Guys I still feel lucky when I land in one piece as I didn't last time in the god awful blustery wind. I will try Martins suggestions of stating with four points and try to get each one correct at a time.

Thanks for the help

[Peter Jenkins]

Hi Martin - thanks for your valuable contribution. You are right about the 3 of 4 points reversed! I'm just beginning to get some semblance of control on the reversed section!

[Swissflyer]

Yes Steve & Willy it was dissatisfaction with slow rolls that made me spend a season working on knife edge flight. My personal objective was (is) to be able to fly the model continuously in any attitude (normal, inverted and left & right knife edge) with “fly the line” control.

Roll from normal to controlled KE came first, then KE to inverted and finally inverted to KE either way – I found that the toughest part as I kept overshooting & ending up in normal flight. Once I had the “control” in any facet, transitioning to the next one was much easier i.e. I was going from one stable “state” to another one.

This is pretty much the same advice as Martin gave on four point rolls but coming from the other direction.

This season I have been practicing that “in the wind” which adds some challenges.

Like you Steve, I train on a foamy, I have a big field across the road where I fly most of the time and take my “proper” 53in span, 700W model to the flying field when I can.

I should say that everything I fly on the big model looks much better than on the foamy! I think this is because the extra inertia smoothes out my errors!

Those big control surfaces on the foamy ruthlessly expose every small mistake; I tell myself that the visual feedback helps me improve…

That said the foamy has its own rewards, my log tells me that with a steady wind in early February I was able to practice slow rolls “stationary” about 30ft above my nose. That was a great chance to test control inputs and fine tune things, it was enormous fun, do try it some time.

Another trick that I “borrowed” from the designer (and one time Czech champion) is to prop hang the model in the wind. If you try this don’t be surprised to see any spectators calling the animal rights groups, the model hangs there and looks like a poor crucified sea bird!

**LINK**

I have trimmed the model for F3A flight, as Michael Wargo says in one of his videos “3D flight is tough enough, why make it more difficult with unstable trim?”

I can only speak for my two models but he does seem to be right, the Zoom Zoom with F3A trim will do everything it should do as a pure aerobat and perform the “beyond the stall” manoeuvres (harrier etc) perfectly well too.

Do you keep a log book? Having a ruthless record of every flight really helps me to decide what to improve on. It is also very satisfying as despite my permanent despair at my bad flying, the log book lets me see that some progress is being made!

A club mate friend of mine flies big helicopters in international competitions around Southern Europe, I recently watched one of his training sessions in total admiration, his comment “so many mistakes!”

Happy flying
Mark

[graeme jones]

Peter - managed some more Clubman schedule practice last Wednesday. Still having trouble with the slow roll i.e. not slow enough. This happens because my thumbs struggle to move the sticks correctly in 2 axes at the same time. My left thumb in particular has trouble giving elevator and rudder inputs at the same time, as needed for the slow roll. I've struggled to fly helicopters for 14 years for the same reason. It's not lack of flying practice, I've been at this now for 45 years! I can fly inverted and knife-edge with no problem, but always over-control in the slow roll.

Back on page 5, 07/12/13, you talked about increasing stick tension, so I thought I'd see if this would help. Discovered that the factory setting on my Futaba 7C is the maximum (unless I increased it myself and have forgotten) while the 6J doesn't have any adjustment. Out of curiosity I checked the stick tension using a digital scales. With the 7C it's about 50 grams to initially move the stick, increasing to 60 grams just before the end stop. The 6J is about the same, but my old F16 Tx from the 1980's, is about 80 grams, even with the sticks set to maximum length.

So does anyone know where can I get some stronger springs?

Graeme

[Peter Jenkins]

Graeme - have you tried contacting Ripmax to see if they can supply stronger springs for your Tx?

[Martin McIntosh]

Try a tool store at a show such as Wings and Wheels. You can usually find bags of springs of all sorts.

[Peter Jenkins]

Here are the judging notes for the Immelman Turn

Immelman turn

Model performs half a loop, immediately followed by a half roll to exit upright at a higher

altitude than entry

Downgrades:

(1) Changes in heading during half loop or roll

(2) Half roll not immediately after loop

The important point to note here is that the requirement for a good score is that the half loop is IMMEDITELY followed by the half roll. There is no pause between the two and if the judges see one that’s another point gone. So, to avoid losing easy points follow the guidance.

Make use of the size of the aerobatic box by not doing this manoeuvre immediately after the 2 loops! There is always the need to establish a line before and after a manoeuvre. By that I mean a short period of straight and level flying.

Remember this manoeuvre precedes the outside loop or bunt so you want to make the half loop a good deal larger than your bunt so that you don’t end up kissing the ground with your fin at the bottom of the bunt!

Again, go back and read the comments on flying a loop, especially in a cross wind, in order to make sure that your track at the top of the half loop is pointing in the desired direction.

Start the half roll just before the aircraft is level but not by much – it must not be obvious to the judges! A gentle squeeze of rudder, in the same direction as you have moved the aileron stick, helps to keep your roll level. Note that you can roll in either direction for this manoeuvre.

And, don’t forget that you need a line after the completion of the manoeuvre. Try and avoid any correction to flight path that is obvious while you fly this line otherwise those are grounds for another deduction in points. Whilst it is easy to say, try and make any corrections early, of small and really unnoticeable amounts and smoothly. That way you can score maximum points for the manoeuvre.

[Peter Jenkins]

The next manoeuvre is the Outside Loop. The judging criteria are:

Downgrades:

(1) Loop not round

(2) Wings not level during loop

(3) Changes in heading during loop

The bunt/outside loop needs to commence on the centre line. Failing to do this leads to….. you guessed it, a loss of a point! Don’t just close the throttle at this point but begin to smoothly retard it aiming to have it closed by the time the aircraft has reached either the 10 past or the 10 to point on the bunt. Also, it is a gentle squeeze you need to exert on the elevator stick to begin the manoeuvre and then watch the flight path to make sure that you are performing a round manoeuvre.

Refer back to the guidance on looping for wind correction both in and across the flight line. Remember the judging criterion of wings not level during loop. This can only really be judged at the top and the bottom of the bunt. So, if you are using bank to counteract the effect of a crosswind, make sure that you have the wings level to begin, end and at the bottom of the bunt. At other points it will be very difficult for the judges to detect that you have a small amount of bank on.

Power needs to be making a comeback from around the 20 past or 20 to position on the bunt. Again, a smoothly operated throttle stick is what is needed. If you are flying a specialist F3A aircraft you may not need full throttle but if not then you will do best to be at full throttle at the bottom of the bunt.

At this point you need to ease off down elevator a touch to avoid performing a figure 6! That is to have a smaller diameter bunt for the second half of the manoeuvre. You are aiming to have the aircraft reach the centre line as it reaches the top of the bunt and at the same height as you entered the bunt. This is not an easy manoeuvre to perform well and requires more practice than a loop to get right.

As you approach the top of the bunt, your throttle should be coming back smoothly to your normal cruise power setting. This is much easier for an ic powered aircraft than an electric powered aircraft due to the lack of noise with the latter. In that respect, if your Tx has a stick alert feature it is very helpful to set the throttle stick position for normal cruise power to give you an aural indication.

If your model has not been trimmed well enough, you may find that the aircraft will screw out of the bunt. You will need to go back to basics to make sure that your control geometry is correct in every detail. In particular, if you have separate elevators are you sure that they are moving exactly the same amount. A very minor difference in movement will roll the aircraft out of the plane of the bunt and you will be fighting to keep the aircraft straight.

That’s why, the best aerobatic aircraft are those that have no warps and control movements that are exactly equal e.g. the elevators are in line and move together at all times.

As regards the size of the bunt, try and make it the same as your loop.

[fly boy3]

Hi all,a foamy to practise aeros. on, not a bad idea. I'm only into normal club stuff, but I can see the logic in this. Any one out there care to nominate such a model. Got to be a budget aircraft, and perhaps a profile design. Thanks

[Peter Jenkins]

The next manoeuvre is a Split S. The model executes a ½ roll and immediately performs ½ an inside loop to recover in level flight but flying in the opposite direction. The judging criteria are:

Downgrades:

(1) ½ roll not exactly 180º

(2) Loop not constant radius

(3) Changes in heading during half loop or roll

Dealing with the first downgrade, if you roll fast you have less need to use rudder to keep the aircraft flying level while rolling. However, hitting the 180° exactly becomes more difficult than if you roll more slowly. In the latter case, you will need to use rudder to keep the aircraft from dropping its nose. So, the choice is yours but remember that you will lose points if your flight path drops too early or you over or under roll. On balance, it is better to learn to use rudder for a slower roll and have more control over when you stop the roll.

The second point is exactly the same as for the loop and bunt so if you have a problem there you’ll have a problem here! The key thing is to remember when gravity is helping and hindering and to adjust your elevator pull accordingly. So, at the commencement of the ½ loop, you won’t need much elevator, however, as you come past the ¼ loop be prepared both to pull in more elevator and bring up the power remembering to balance the curve to suit any headwind into which you are flying. It sounds more complicated than it is. Try it a few times in different head and cross wind conditions and you’ll begin to get a feel for what you’ll need to do to achieve the ideal flight path.

The last point is one I always struggle with. It is very easy to carry some bank into the ½ loop. You might also be using a small amount of bank to counteract a cross wind. What this does is to change the heading of the model – with a cross wind that’s exactly what we want as we are trying to counter the wind pushing us away from the desired flight path. Conversely, if there is no cross wind or you get the bank angle wrong, as you exit the manoeuvre at the bottom the aircraft will either be flying towards or away from you depending on whether you were carrying the left or the right wing low. Using a small model to visualise what the wing planform needs to be as the aircraft descends the ½ loop is extremely helpful. The small model doesn’t need to be an exact replica of the model you are flying although if it’s a biplane then you really want a biplane to help get the aspect correct.

So, there you are, having turned the aircraft through 180° and descended to position yourself for the next manoeuvre you are ideally positioned for the Cuban Eight – or not!

This is a deceptively simple manoeuvre but there are quite a few complications that you need to address to get it absolutely correct. An easy way to lose marks is not to begin the ½ loop immediately you have completed the ½ roll.

[Peter Jenkins]

Hi FB3 - I've been looking at a Foamy on the HK website. It was listed in the UK but is out of stock but is in the Euro Warehouse. The aircraft is called the Arcus F3A aerobatic biplane. The aircraft appears to be a copy of the Wolfgang Matt Amethyst F3A biplane which I just happen to have! What's good about a biplane F3A machine is that it can be flown more slowly than a monoplane, it has a very powerful fin/rudder so you don't need much rudder when rolling slowly and it will knife edge with consumate ease. There is a video of the aircraft being flown on the link I've attached. The manoeuvres are flown much faster than you would really want to for proper F3A but it serves to show the capability of this little foamy bipe. I suspect that if you go for too small and light a foamy then the wind will play havoc with your attempts to fly precision aerobatics. I don't know how much postage will be from the Euro warehouse but you could also wait and see if it appears again in the UK warehouse. I am very tempted to get one of these myself!

[Peter Jenkins]

F3A World Cup

The FAI run a series of Continental-wide aerobatic leagues and a round of the European F3A World Cup will be taking place in the UK next weekend. Actually on Friday 30^th May, Saturday 31^st May and Sunday 1^st June near Ashford in Kent.

Full details are available here but you will have the opportunity to see some of the best European Aerobatic pilots, including all of the GB team flying in this 3 day event. Pilots from the following countries will be flying: Germany, France, Poland, Belgium, Finland and the UK.

The website above gives the details of how to find the private airfield and there is no entry charge. Click on the Venue tab on the website and you’ll get a Google Map showing the location with a Lat Long and if you use the Google Maps navigation function (you may need to enter your own location) Google Maps plots your route and ends with a white dotted line showing you the access route off the public road following a farm road to the airstrip.

When you get there, if you ask for Ashley Hoyland, PRO of the GBR/CAA and tell him you read about this event from a post by Peter Jenkins, he will tell you what’s happening and if you’d like to try your hand at scribing he can arrange that.

Scribes are needed to sit beside the judges who then mutter the score (so that the next judge can’t hear) of each manoeuvre flown. The Scribes job is to write this number down against the next manoeuvre on the scoring sheet. You get a front row view (you are seated 10 mtrs behind the pilot) of proceedings!

In the past, the owner of the airfield has put on a short display with one of his aeroplanes at the end of the competition on Sunday afternoon.

Food and drink will be available during each day.

This is a great opportunity to see some international experts flying FAI standard aerobatics.

[chris Bond - Bondaero]

Just take delivery of my Hobbyking Arcus foamy so once it stops raining I will let you know I think postage was about £8

Thoughts so far

Arrived in four days in perfect condition

Very easy to put together

one aileron does not seem to centre too well

will use stock set up with 4s 1800mah

esc does not seem to shut off if tx signal is lost so use your failsafe settings

Overall very very impressed for the price