My name is Sasha Marvin, US CFIG and World Champion with team Italy at the WAGAC in 2012, the World Advanced Glider Aerobatic Championship. I moved to the USA last year and teach top level glider aerobatics at the Seminole Lake Gliderport, Clermont FL. My background as an aerobatic pilot/instructor includes training with Sandor Katona (the living legend of Glider Aerobatics) and I had the opportunity to exchange knowledge and assimilate the aerobatic cultures of different countries, Italy, Austria, France, UK, Germany, Poland, Slovakia, Finland, Russia & Check Republic.
Disclaimer: be aware that this briefing is intended for already trained pilots with the required aerobatic skills developed. No one that haven’t been done enough training with a qualified aerobatic instructor and hasn’t developed enough situational awareness, should perform any of the following. Said that, respect the glider limitations you find in the operating manual.
The IAC rules for the Sportsman wants 45° degrees lines to be flown at 30° and since there is no difference in the techniques, let’s get deep into it, as we would do if we were training for the World Championship.
This sequence critique will outline some differences from power aerobatics, too.
Box Entry and penalties
There is no high penalty device used in the US nationals, however the judges know and can understand if you’re too high or too low, so train to manage the energy, avoid long lines and pay attention to your entry and exit speeds.
Wing wag (start your program)
Start diving at minimum speed at 4000ft AGL. Dive deep and do two wing wags on the down line, level and do the last one once level. You will lose some energy so there is no way you can end higher than 4000ft at the top of the loop of the half cuban.
Fig.1 Half Cuban - Starting figure - K19
BOX: begin the figure at 3/4 of the box, so in between the judges position and the end of the box.
TECHNIQUE: The 45° up line has to be a straight line and for the Sportsman has to be performed at 30°. The first segment before the half roll and the second segment after it have to be of same length. Count 1-2 in the first line and 1-2-3 in the second line.
After the half roll, you’ll need to get automated with pushing the stick forward enough, this because you want to fly on the same line you were traveling before the half roll. Stop wings level with horizon to keep the heading on same direction.
If judges see different length of the two segments or they see a variation of the heading from the initial segment, that will be no good for the scoring.
You’ll need enough speed to do a smooth 5/8th of the loop. Watch out because there has to be a line after the half roll. If you begin the loop immediately with no line, you might get a Hard Zero (HZ). The half roll has to be stopped with wing level, with less barrel as possible, and no corrections after it.
ERRORS: different angle on the second line after the roll, not rounded circle of the 5/8 loop, desaxe after the half roll, so ending figure with different direction from how it was started.
Fig.2 Canopy up Humpty Bump K15
BOX: begin the figure at the 1/2 of the box
TECHNIQUE: The vertical lines has to be parallel, straight and no angle pitch or roll variations during the travel. The top half loop has to be narrow and flown, wing level to horizon, but you need enough speed to not stall on top. Draw a nice circle half loop. So keep slightly positive on the up line and slightly negative on the down line. Same entry as exit speed. Same G sensation to go up, same G to exit, so you'll be sure that the two quarters of loop will be of the same radius.
ERRORS: Most common errors: super narrow half loop, slow speed before half loop and stall, different angles in the up and down lines, corrections in the lines.
Fig.3 180° aerobatic turn K4
BOX: begin after the humpty and give normal separation in between the figures.
TECHNIQUE: Set a bank that's 60° (better more than less) do it hard! And keep that angle for the whole turn. Any variation will be -1 point. Manage speed with rudders. Do not vary the bank. Level hard like in a fighter.
ERRORS: Most common errors: variation of bank, variation of speed, pitch, slow speed exit.
Fig. 4 Humpty Bump K13
BOX: begin on half of the box, if you’re not there wait! Do not begin right after the turn.
TECHNIQUE: Lines must be parallel, vertical up must be 90° up and vertical down 90° down. Fly the top half roll, avoid stall so use pilot instinct to begin the half roll. Do not do variations in the lines, because they will deduct 1/2 or 1 point from the scores. Same entry same exit speed.
ERRORS: Most common errors: super narrow top half loop, stall due to low speed at top, and different angles in the up and down lines.
Note — Like Fig. 1 (the half cuban) Fig. 5 and Fig. 6 are those with more K factor (difficulty). Put special effort and attention in these 2 figures here for best scoring!!!
Fig. 5 the 45 up Diagonal Humpty K18
BOX: fly a short line after Fig. 4 and fly a longer line after the end of this figure. You want the sequence that comes after Fig. 6 to actually fit in the box.
TECHNIQUE: The first part is exactly as the half cuban eight (fig.1) so review above and mark the 45° (30° Sportsman) line down after the half loop. Look outside on the wing tip to know where you are. Once is time to mark the 45° (30° Sportsman) down line slow down the roll rate and be precise. Keep the line do not do variations. 10kmh before the exit speed pull quite hard and release smoothly to level.
ERRORS: Most common errors: different length of the line elements before and after the half roll, different heading after the half roll, different angle after half roll, diagonal line down flown at different angle, variations on diagonal down line, stall at the top of the figure.
Fig. 6 Sawtooth K21
BOX: begin this figure quite after the judges, or at the 3/4 of the box.
TECHNIQUE: This figure looks simple but hides a lot of potential traps. It is similar to the beginning of the half cuban eight, but what changes here is timing. Because it looks simple even a very minimal error here becomes a big error. To get the two lines before and after the half roll of the same length you need to work on timing. And naturally push up the nose a little bit after the half roll. Speed is an important factor. You don't need a lot of speed but you want to draw a long line and impress the judges, right? So start at your usual speed, mark the 45° up (30° Sportsman), count shorter on the first line, do the half roll, and count longer on the second line. As soon as you feel the buffeting do the 3/8 of the top loop. It's a very narrow loop, but it has to be flown and avoid the stall, that will be very visible, as your deductions. Mark the vertical, do not do any variation when established the line down. Always look the reference on the tip wing, slow down the loop ratio before to mark the vertical for better style and precision. Then bring your gaze on a point down on the ground, and keep it. The glider want's to pitch up with speed, so keep it on that line. Focus the airspeed indicator, 20 kmh (10kts) before the exit speed pull hard enough then release before exit.
ERRORS: Most common errors: second line after the half roll on a different angle, wing not level with horizon, so big desaxe (different direction) from the initial line. Stall on the top. Variation in the last part of the vertical down. (Banana!!!)
Fig. 7 Roll K14
BOX: the roll should be at the 1/2 of the box, right in front of the judges
TECHNIQUE: Do not change roll ratio, especially in the second part. Use proper push forward with slow ratio roll gliders, especially just at the inverted position and before the second knife to keep heading.
ERRORS: noticeable altitude drop in the second part of the roll, exit direction way off the initial direction.
Fig. 8 Cloverleaf K17
BOX: normal after the roll, do the quarter roll up to exit in the direction where you have more space.
TECHNIQUE: pull up as in a loop, look outside (left) in the direction of the roll, and at 45° begin to add stick aileron slowly, so no need of rudder for correction, once reached 90° (or at 1/4 roll) stop adding aileron - check wing level with horizon - and keep flying.
ERRORS: quarter up ends before or after so exit direction is off the 90° axis of what it was supposed to be.
Fig. 9 Stall Turn (Hammerhead)
BOX: fly into the wind!
TECHNIQUE: Usually in the competition we don't wanna see the bank preparation, so you will have to train adding a little bit of aileron in the pull, instead of doing it separately because it is visible (as many instructors teach in the beginning, me included). You will fly in front of the judges. For that reason the wings must go up really levelled horizontally. The top turn must be executed on the same flight plan of the vertical up plane. Avoid variations during the vertical lines. Little positive up, little negative down. If the wing tip reference is well set on your glider you should have it perfectly aligned at 90° on both up and down travels. The stall turn has always to be flown into the wind, so you have to know how to do it on both sides. There’s a lot more details to know about stall turns. Come train.
ERRORS: up and down lines flown with different angles and variations, top pivot turn not done on same vertical flight plan, late top turn, anticipated top turn, “banana” on exit.
WARNING: If you notice that you're too low for some reason, abort! Don't do it if you don’t have plenty of altitude. Try save energy on the top figures and try not using too fast speeds.
Program END - Wing Wag! If you do all good as described above expect the GOLD medal!
BOX & WIND MANAGEMENT: depending on wind direction you will have to adjust your separations between figures in order to be properly centered and on position.
GROUND PREPARATION: Always try your flight at least three times in your mind on the ground and try to prevent any possible cross wind effects to plan your flight in the box!
This was a typical pre-briefing sequence critique, discussing on main key factors and details. As done in the training season in preparation of the world championship. This is part of how in 2012 we won the WAGAC. You will definitely find a benefit applying this training standards.
Well, if you read the whole thing, leave a comment!
I teach Unusual Attitudes, Spins and aerobatics for new and experienced pilots, at Seminole Lake Gliderport, Clermont, FL
US CFIG Glider Aerobatic Coach Trainer"Working to build the East USA Glider Aerobatic Team"
I do rides and teach Aerobatics at the Seminole Lake Gliderport, Clermont, FL. Open all year!http://www.sashamarvin.com