By Jeff Seaborn, EAA 793688, Chair, EAA Canadian Council
As mentioned in last month’s Bits and Pieces, the Western Canada Aerobatics Championship was held at Rocky Mountain House, Alberta, over the September long weekend. This year was the first time in recent memory that we had great weather all weekend. The pilots had no excuse for anything but spectacular flying. The competition attracted nine pilots from Alberta and two from Manitoba. We missed the additional interest from British Columbia this year, but we did have one new pilot fly his first-ever competition and we expect to see him back in future contests. Hopefully we can attract some interest from Saskatchewan, too.
There are five different levels of competition — Primary, Sportsman, Intermediate, Advanced, and for the really dedicated and experienced, Unlimited. Each level gets successively harder with more challenging manoeuvres, a quicker pace, and higher g loads.
For me, the contest was my first time competing in Advanced category. The flying in Advanced is a big step up from the Intermediate category. Advanced has a lot more negative g manoeuvres and inverted flying, as well as combinations of figures that require you to think three dimensionally. Your orientation in the aerobatic box is important and it’s easy in the midst of the g’s and stresses of the flight to get disoriented and make mistakes.
A typical contest is three rounds of flying. The first round is where each category flies the “Known” sequence. Each category has its own Known sequence defined by the International Aerobatic Club at the beginning of the year. This gives the pilot the opportunity to practice it as much as they want prior to the contest. It also means that the pilots in each category are flying the same sequence in the first round. The second round allows a little more creativity. Pilots in the Intermediate through Unlimited category have to design a sequence to fly. Although it’s called the “Free” sequence, there are many parameters around the design and your design has to be approved by a judge to be allowed to fly it in the contest. It’s a fun challenge to create a sequence that includes all the required manoeuvres, highlights your favourites, and has the proper flow in flight. I’ve created a few sequences that looked great on paper but when flown, didn’t work out. Back to the drawing board. The final round for the Intermediate through Unlimited is the “Unknown” sequence. The Unknown sequence is given to the competitors during the contest. Competitors have not seen the sequence before and we don’t get to practice it in the air. We have to visualize the entire flight and practice it on the ground by doing the “Aresti dance.” You may have seen air show pilots or aerobatic competitors doing this before their flight. Their hands are often up beside their head and they are visualizing flying through their sequence while on the ground. This is Advanced winner Jerzy Strzyz going through one of his flights on the ground.
The first time we actually fly the Unknown sequence is in the contest, in front of the judges. I enjoy the Unknown sequence as it really stretches you as a pilot. There are little gotchas in the sequence that don’t appear to be too challenging on their own, but when you look at the positioning or order of the figure, they are tougher than you first realize.
To briefly explain the Aresti diagram, upright flight (or positive g manoeuvres) are shown as solid lines, whereas inverted flight (or negative g’s) are shown by a dashed line. Rolls are shown as arced arrows. As the pilot, you can choose which way you roll but sometimes the roll direction is dictated by the direction you need for the rest of the figure or sequence. Arcs that cross the line of flight mean full rolls, or 360 degrees of roll for each full arc. See separate image of full roll and half-roll arrows. Arcs that don’t cross the line of flight are half rolls or they may be partial rolls with descriptions beside them to explain them more clearly. For example, the“1/4” that I highlighted in pink on figure 4 means a one-quarter roll. That roll happens to be on a vertical line up. The pink was my cue to the direction I wanted to roll. Snap rolls are the isosceles triangles. Like rolls, a full snap roll (360 degrees of roll) is shown by a triangle that crosses the line of flight where a partial snap roll is shown by a smaller triangle that doesn’t cross the line on the diagram. See examples of full-snap and half-snap triangles on the attached image. Figure 5 shows a half snap (i.e. 180 degree snap roll) on the vertical down line. The rest of the diagram is somewhat intuitive. That is, expect to fly the same pattern in the sky as shown on the diagram. For example, figure 7 is a looping figure. However, because it’s dashed, it’s an outside loop starting from inverted and finishing inverted. Oh yeah, don’t forget the full roll at the top of the loop.
It was an interesting sequence in that the very first figure starts inverted into a one-turn, inverted spin. At the bottom of the spin is a 3/4 loop to inverted again. That 3/4 loop requires a pull of 5 or 6 g’s. 5 or 6 g’s from upright isn’t too bad, but coming into it from inverted means your body has dropped your blood pressure and you have to concentrate and grunt to not grey out or black out. What a great way to start the sequence!
It was a tough sequence with a lot of pre-planning and thought required to ensure that you’re rolling the correct way on the vertical lines, so that you end up in the correct direction, and are in the correct position in the box. Figures 4, 5, and 6 in this sequence were critical to your position in the box and direction of flight and those figures are to be used to adjust for the wind. Figure 6 requires the pilot to be at the righthand side of the box (from the judge’s perspective). It begins with the pilot flying towards (or away) from the judges. It is a hammerhead with a 3/4 roll on the way up (which I highlighted in green to cue me to the direction) and a half roll on the way down. You end the figure by pushing to inverted to prepare for the inverted, outside loop of figure 7. The push at the bottom of the hammerhead is at high speed and it requires a lot of commitment and effort. I was pushing just over -5 g’s at that point. Unlike positive g manoeuvres, where you clench your abs and your butt muscles to prevent your blood from rushing towards your feet, negative g manoeuvres push all the blood towards your head and there’s nothing you can do to minimize that affect. You just have to tolerate it. So much fun!
Going back to the hammerhead of figure 6, the direction of that 3/4 roll on the up-line is critical to the direction you finish the figure. If your 3/4 roll is in the wrong direction you will end up flying from the judges left to their right. Do that and your figure will be given a “hard zero.” Regardless of how beautiful it was or how perfectly you flew it, you get a big juicy zero. Nothing. Nada. Zilch. Why? Because you flew the wrong direction. Often too, under the stresses and strains of the flight, a pilot will miss a figure. Sometimes that missed figure puts the pilot in the wrong direction and all the subsequent figures become zeros as well. In the heat of the flight, these things happen.
I did get a hard zero on one of the manoeuvres in the Unknown round. I messed up figure 11 at the bottom of the picture. It’s a full roll, followed by a half loop up to inverted, a full snap roll from inverted to inverted, then a half roll in the opposite direction to finish upright. Unfortunately, I’d never practised a full snap from inverted to inverted. Although it’s not overly difficult, my instinct was to stop the snap upright. I stopped the snap a little more than halfway around, then backed up to upright, then did a full roll to finish the figure upright. What I essentially did was a half snap then a full roll instead of the required full snap and a half roll. I knew I’d messed up as soon as I’d done it and of course, the judges saw it. I laughed at myself and continued with the final figure.
That hard zero caused me to lose a few percentage points, dropping me from 4th to 5th. Yeah, there were only 5 of us competing in Advanced, so I was 5th out of 5, but I was okay with that. I finished the contest with a score of 74.4 percent. I was pleased with that for my first endeavour in Advanced. Aerobatic competition is really a competition against yourself. You are working to fly your best and impress the judges. Because of this, there’s a lot of camaraderie and support amongst the competitors. I’ve found everyone to be encouraging and happy to be there. Of course, the contest doesn’t happen by itself and the pilots only make up a small portion of those who are there. The contest couldn’t happen without the support of the many volunteers who are enjoying the experience as well.
If you’re interested in aerobatics, whether as a pilot, a judge, or another volunteer, come out to a competition. We’d love to see you out there. If you’ve never competed and you’re interested in competing, the Primary and Sportsman categories are much simpler and designed to introduce the pilot to the experience of competition without the strains and loads experienced at the higher levels. One of my favourite pilots to watch compete flew an RV-6 in Sportsman. He flew it beautifully and smoothly. Never overstressing the airplane or its engine. And isn’t that what it’s all about?