The Golden Angle – What’s Needed To Win
Lake Balaton produced one of the most exciting races in Red Bull Air Race’s 14 seasons. One of the reasons it was so captivating was due to the variety lines the pilots could take to try and shave time off their laps.
It didn’t come down to guesswork. After each session every Master Class pilot could be found hunched over a laptop in deep conversation with their tactician to see where they went wrong, and where they could improve.
One outfit that worked out the track and soared up the leaderboard was the Cashback World Racing Team. Pete McLeod, the team’s pilot, finished third, just 0.127s away from race winner Matt Hall and a mere 0.009s behind second place Ben Murphy. It was a complete change in fortunes for McLeod, who had finished 9th in the first two races of the season.
Werner Wolfrum joined McLeod’s team as tactician at the start of the 2019 season, but he’s no novice to the sport. Wolfrum was part of Hannes Arch’s team from for the 2015 season, which saw the Austrian take two race wins and finish third overall – so he knows how to find that winning line.
“My special skill is that I have developed special tools to show Pete the comparisons in a 3D visualisation,” says Wolfrum when talking about what he brings to the table. “We can move our viewpoint around a pattern and can compare using a look at the line ahead, to see how it will proceed in the next seconds. A picture tells more than thousands of words, and an animated 3D view more than a million...”
When looking back on his pilot’s fantastic result in Hungary, Wolfrum knows exactly where he took his advantage over other pilots. “In Balaton, Gate 5 [which was also Gate 13] with the track limit line was the challenge and key, especially with the wind. Taking it flatter increased the effect to ‘surf’ on the wind drag, but with the danger to hit the Track Limit Line. To take it vertical is safe against the TLL, but consumes more energy,” he explained. “This is where we needed to find the ‘Golden Angle’, and it was not easy to estimate, especially because the changing wind had a huge effect.”
Explaining the Golden Angle
The ‘Golden Angle’ is a term that Wolfrum and McLeod use to ensure they find the perfect line through a particularly tricky gate, but Wolfrum expresses that it’s not easy to clarify.
To visualise and explain the line to McLeod, Wolfrum took a sheet of paper and held it between the track limit line and the gate. He bent the paper to show McLeod that if he flew a flatter turn, he would touch the Track Limit Line, but if he went more vertically, McLeod could find some space.
In the event of more wind coming in from the side, the pilots could take a little bit flatter line because the wind drags them away from the Track Limit Line. So by using this method, Wolfrum demonstrated to McLeod that pulling extremely hard, and on the limit, might be the shortest method. But after the Vertical Turning Manouevre, the plane was always slower than a vertical turn that was not perfect in terms of radius. If the radius was a little bit wider, the plane would be faster.
From these combinations he could understand what to do to fly more or less the optimum line. “It makes no sense to give the pilot a mathematical expression or to tell him, ‘These are the track parameters, fly it...’,” says Wolfrum. “The only way that he can use and work with the ‘input’ is to develop a ‘feeling’ about the shortest line. That – in my opinion – is only possible in a close discussion about the problem zones or the options in the track. The pilot has the most experience – and always more than a Tactician. So for me the feedback from my pilot is at least as important as the data we get out of the download after a run.”
As with most races, the wind not only changes the conditions of the track, but also how the pilot will need to fly it. At Lake Balaton, every session was different. In a short space of time, the pilots experienced weather that went from rain and 22kts wind, to no wind and glorious sunshine. So does the Golden Angle change in these variable conditions? “Yes, and we had many discussions about watching the wind before you enter the track. You can get information that can help you estimate the wind, for example, from smoke coming out of a smokestack somewhere, or the waves on the water surface, or how the pylons move. If you have more wind, then a little bit more angle is possible, about five degrees or 10 degrees,” explains Wolfrum.
When flying at 200kts, five or 10 degrees at that speed is difficult to judge. Wolfrum compares it to driving down the highway. “That feeling when driving very fast that the road becomes more and more narrow? You have to imagine that: to get the right target as things feel closer and closer, 10 degrees is really nothing at that speed. And that is what I am always fascinated by. That these millimetres on the stick work under 10G at that speed, for me it’s still fascinating how it is possible. And this is only possible if pilots feel a bond with their plane, the extended body. There are nuances that make a huge difference. Millimetres make a huge difference, and it could be easy to do too much. So Pete needs to feel it, to sense it on his own, not by a number or an angle I could give him.”
McLeod is quick to praise his tactician and what a valuable member of the team he is. “Werner pays attention to ALL details of analysis… from engine and aircraft setup, to the line being flown including 3D modelling and analysis, and even the efficiency of HOW that line is flown. It’s not just the path you fly, but how it is flown that can make a huge difference in today’s Red Bull Air Race!”
Teamwork to find the best line
Every team in the series will have their own, unique way of working with each other. So when there is a tricky line, or something isn’t quite going to plan, how do tactician and pilot come to a solution?
“I point out the options that I see, and Pete maybe has other options in his view, and we discuss the different options,” continues Wolfrum. “For me it makes no sense to work out a track or a concept and then go to Pete and say, ‘This is the solution, do it.’ The best thing is to talk about it and then Pete has the same visualisation of the track, because he has to fly it. The target is to open Pete’s mind to different views because he has to see the different options and all possibilities, and then he, and only he, can select the right one, because he knows and he feels what his plane does.”
Wolfrum has programmed his simulator for two functions: training and visualisation. McLeod doesn’t enjoy sitting in the simulator because he can’t ‘feel’ the G loads and that is a huge factor in the amount of input he needs to put into the stick. But, for his visualisation the simulator was very helpful.
Wolfrum and McLeod are able to move through every point in the track, around the track, from the outside, from the side, and from directly in front of the gate. And that is the other function of the simulator – to put out all data from the plane, combine it into the line in the simulator, and then look at it virtually from all sides. “These kind of discussions work out, or make clear, the components and the relations in Pete’s mind that he sees the combinations. Pete’s skill allows him to work with such information extremely well to find the right way,” clarifies Wolfrum.
McLeod concludes by agreeing with his tactician: “The pilot ultimately has to go out and complete the line and will always be limited by human factors… this is why this tool works so well, because coaching the pilot visually is a very efficient way to deliver the information.”