Dedicated to the Promotion of Electric Propulsion in all types of Aeromodeling

EMAC Rules & Information


  EMAC Has Been Cancelled by order of the SEFSD BOD, 7/2017.




      ?    1. Six practices and best four will be used for the final standings.?
    ?    2. Anyone can move to adifferent class if they wish, no restriction.?
    ?    3. 4 classes will be flown: Basic, Sportsman, Intermediate, Advanced.?
    ?    4. All participants are encouraged to be prepared to fly two sequences each round.?
    ?    5. All sequences will be from the IMAC 2017 schedule.?
    ?    6. Judging rules will be from IMAC.?
    ?    7. Schedule to be announced and records kept on the SEFSD site or linked.?
    ?    8. Awards given at the year’s end. At least first, second, third in each class.?
    ?    9. All SEFSD field rules shall apply.?

    •    See Tim’s EMAC Flying & Judging Seminar


 RC-Airplane-World has a nice website with good information to get started in aerobatics.





Feb 19: Aircraft Trim Clinic and EMAC Demonstration.  See Calendar for 2017 EMAC dates.












Sources explaining Aresti symbolls: Video

Learning Aresti Symbols Video




Assuming that you now have an airplane suitabe for basic aerobatic operation AND you have installed a good power system and have several battery packs (one is really not enough)… AND you have the best servos that your pocket book can stand….. AND you have zero slop in all flying surfaces…then you are ready to proceed down the road to precision aerobatics.

Trust me that if you go cheap on any of the aforementioned you risk distress and head scratching which will slow down your progress.


Setting up your aircraft is next and you maybe asking “what do I do next?”


Next step is… the aircraft and watch what it is doing. Hopefully it will stay straight and level with power on and power off. Pull to upline vertical and go 300 to 400 feet up without correction from you. If it fails to do these reasonable well then you must adjust:


      1. Center of gravity
      2. Engine thrust
      3. Decalogue of wing or stab


Two tests that I suggest for CG, assuming that you have set it at manufacturer’s recommendations, are…..Test # 1. get up high and fly downwind and roll to inverted and fly for 200 or so feet and watch to see how much down elevator is required to keep it in level flight. It should require a little bit. If it climbs or falls substantially then you must adjust the CG until it does what I described.   Test # 2. pull to a 45 degree upline and roll to inverted again and watch how much it drops the nose. Without down elevator it should just gradually begin to arc toward the ground……very slight arc….the longer that line goes without arcing the closer it is to being right. Down wind test may arc a little less than upwind.


Keep your adjustments small until you achieve this balance because it is essential to get this right. Fudge toward the aircraft being a little nose heavy as it is easier to land and will not be as pitch sensitive and it will stay on heading a little better that way.


If power on power off shows the airplane to climb and or dive then the thrust line is in need of adjustment. If you are carrying up trim in your elevator to get it to fly straight and level at full power than you have too much down thrust in the set up. If the airplane stays straight on horizontal flight when you power up and power down than move on.


If this is in the bag then begin to look at how the top of a vertical line ends up. Does the aircraft go left, right, to the wheels or to the canopy? Small adjustments to the motor thrust line will pay dividends and keep it straight a little longer. A small washer here or there will usually do what you want to get that line a bit longer.


Your ultimate goal is to have an aircraft that is in a groove in horizontal and vertical flight…….NOT BUSY….. as in requiring constant corrections to keep it in a straight line.   If your airplane is busy than your thumbs will be busy and that is definitely not a good thing.


If your aircraft is flying straight then be happy, burn electrons, and bring the aircraft and fully charged batteries to the first clinic for more advanced setup tests and modifications.


February 19 at 10am.   Pedro Brantuas, Ray Fulks and I will be there to consult with you and fly your aircraft and make further adjustments to: Exponential, amount of throw, differential, and small mixing programs that will make your thumbs relax even more.


Tim Attaway






By Tim Attaway




            One of the first things one must ask oneself is do you like a challenge. Precision aerobatics is a challenge that will infect you with a desire to learn to fly straight and loop beautifully and then expand on these two essentials. When asked what to practice first my standard reply is learn to fly wings level and do loops that maintain constant radius and stay on heading. Sound simple enough? The neat thing about getting into this is that any aircraft that is straight and set up correctly will allow you to practice these things anytime you want, adding little things to your repertoire until you are able to do a number of really nice looking figures. The basic figures that comprise the beginner level are really simply horizontal lines, vertical lines, 45 degree lines, simple axial rolls, and then spins and stall turns to provide a bit of spice.


            When you have soloed and you have moved up to more challenging aircraft…perhaps a low wing tail dragger. Take offs and landings are in the bag so to speak and you are looking for new things to try then pilots frequently are caught rolling and looping and keeping good control of the aircraft all of the time and they begin to watch what others are doing with their aircraft. Often times you will be impressed by someone who seems to be disciplined and is trying new things. You want to go there too but you do not know how to get on that road.


            The road begins with watching the action at the field and picking out certain aircraft that you like the look of and can afford…both time and moneywise and talk to those that are flying these aircraft. Many new aerobatic planes exist on the market and asking questions about them is a terrific idea. One club member that comes to my mind is Craig Hunter who approached me repeatedly when I was flying a Fliton Extra 330 and plied me with questions about this and that and took pictures and asked how I liked the plane. This went on for quite a while and I was wondering if it would come together and sure enough I know that he is successfully using that very good airplane to practice precision aerobatics.


            Once an aircraft has your fancy and you think it will fly straight then the next thing you must do is put it together correctly with the best servos and dependable power system that you can afford and begin to fly it and watch what it is doing when you try to fly straight lines of all types. Here’s the thing: light weight means a light wing loading…..a very good thing…., you must then get the center of gravity correct, you must get the thrust lines correct, and you must get the control throws correct.   When these are achieved you will be amazed at how much pleasure you will get from flying that aircraft. Small airplanes are at a disadvantage because they tend to jump around a bit and seem to flit around instead of groove through aerobatic maneuvers. The larger the aircraft the more solid it feels through turbulence because of the higher Reynolds Numbers. RN is the laminar flow principles that air produces as it flows through or around an object.


Google it if you would like to find out more about RN.


            This installment, as you noticed, is all about the important questions… you want to fly smoothly and do you have the right tool for the job?   Once you get past these two in the affirmative then the next stage in development is to try to trim the aircraft to fly straight and level without touching the sticks….(once in level flight). There is so much to learn in setting up a good aircraft but when you do have one set up and you like the feel of it in flight then you are ready to try loops that have constant radius throughout and slow rolls that require small inputs on rudder and elevator to hold the heading and roll rate constant. Think about flying the nose of the aircraft and making your rudder and elevator guide the nose at all times by pressurizing those two surfaces. There is nothing more excellent and exciting then to see a brilliantly performed slow roll from one end of the field to the other. Once you learn to do them then rolling loops and circles are just around the corner.