In the Red Bull Air Race, two laps around a low-altitude, high-speed track, are performed with a prescribed set of maneuvers. The biggest and most complex maneuver is the half-Cuban eight.
Usually, at the end of a pilot's first lap, the half-Cuban eight is performed in order for the pilot to re-enter the track and start the next lap. However, this isn't always the case and the only city where you cannot find a half-Cuban is San Diego.
It's a very important move to make simply because turning around requires a lot of energy and space, hence critical time will be used up. When completing the gate before the half-Cuban, a pilot must waste no time in pulling the maneuver.
For every second wasted after the exiting gate, a pilot tacks on another second for re-entering the track and thus compromises his race. So, this has to be done with precision and speed. Basically, pull too early and you get a penalty; pull too late and you lose time.
The half-Cuban eight is also the maneuver that subjects a pilot to the most g-forces—sometimes as high as 12. Any higher and you're disqualified, as was seen with Paul Bonhomme last year in Porto: the result of pulling over-g during a half-Cuban.
To execute this particular maneuver, a pilot goes through the exiting blue gate and once complete, pulls up on the joystick until he's fully inverted and turning back into the track. While making his descent into the track, the pilot rights the plane from its inverted position and continues on with the race.
It sounds easy, but when looking at the various angles or lines that pilots take to minimize their loop time, they can either go very steep which results in less drag, but more loop time, or they can go for shallow angles which result in less loop time but pulling drag and thus a slower re-entry.
It's a gamble and no two tracks have the same conditions for performing an effective half-Cuban. Abu Dhabi requires a shallow loop with a bit of deviation while other places like Porto require a steep angle.
It is examples like this that show how much wiggle room the Red Bull Air Race has in its tracks and how much, for lack of a better word, creativity, pilots can use when it comes to air racing.