Talk Like A Tactician
Pilots in the Red Bull Air Race World Championship rely on their brilliant tacticians to help them find the best racing lines in the track, but to make the most of tactical advice, you have to understand the lingo.
Here is what you need to know (in alphabetical order):
Drag: the aerodynamic force that opposes a raceplane’s movement through the air. Think of it as friction: drag can be created by something as tiny as dirt on the paint surface, let alone the actual shape of the aircraft. And then there is the added complication of induced drag, which happens when the distribution of air is not uniform on the wing. But by any name, drag is the enemy of speed.
Energy management: the most efficient way to fly through the racetrack, which is not necessarily the most aggressive line, because some ‘aggro manoeuvres’ can actually create drag. “Energy management is vital. Smoothness is the key to maximise speed,” says Michael Stock, tactician for Matthias Dolderer Racing.
Flat turn: a form of cornering that is executed horizontally, with the raceplane flying more or less at 90° of bank on a line parallel to the ground. In theory a well-executed flat turn keeps the speed in the plane better than a Vertical Turning Manoeuvre, but given physical and safety constraints in some racetracks, pilots often go vertical.
G-Force: what causes your stomach to feel funny on a roller coaster. In super-simple terms, it is a measurement of acceleration in relation to Earth’s gravity. Just by standing on Earth, you are experiencing 1G, which is equivalent to your body weight. At 10G, you would feel a force equivalent to 10 times your body weight. Whereas in Formula 1 and most of other car races the most of the G load is parallel to the ground (up to 4G in X axis while accelerating and breaking plus the Y axis while turning), in the raceplanes the G load is concentrated on the +Z axis (downward direction) compressing the pilot’s spine. For safety, Red Bull Air Race rules impose strict penalties for going over defined G-limits, including a “Did Not Finish” result for reaching 12G in a World Championship run.
Gate offset angle: the horizontal position of the wings in relation to the Air Gate pylons. When a raceplane can fly straight through an Air Gate, there is a relatively comfortable gap between the wings and the pylons, but when the pilot must approach from an angle, the proposition gets a lot trickier. Think of moving a big piece of furniture through a tight doorway when the surrounding walls do not let you go straight on and you will get the idea.
Heading: the direction in which the nose of a raceplane is pointed. However, ask any pilot who has ever hit a pylon on a blustery day, and you will find that even if your nose is pointed one way, the wind can push you off that heading. That is one reason why tacticians have to take weather conditions into account.
Inertia: the tendency for an object to keep going the way it is already going, resisting changes in speed or direction. Blades’ team tactician Neil Furness explains that when, on paper, a Vertical Turning Manoeuvre appears to begin after a certain Air Gate, in the sky the pilot should actually begin the turn even before he gets to the gate: “Ideally, we want to have that plane turning as it’s going through the gate, to overcome the inertia.”
PRU: Position Reporting Unit, or what Technical Director Jim Reed calls “the brain.” Used exclusively in the Red Bull Air Race, this small black box in the raceplane fuselage records aircraft parameters at a rate of 1,000 times a second, providing the exact position of the raceplane in real time as well as factors like speed, RPM and G. Each team receives data from their own raceplane’s PRU, which is key for tactician analysis.
Racing line: the flight path of the raceplane. “You want to travel the shortest amount of distance from gate to gate, but to do that, you may have to pull more G, and that will have more induced drag, and more induced drag means less speed,” notes Furness. “So you have to find a fine balance.”
Run: a circuit of the complete racetrack as it is defined at any given location, which almost always includes more than one lap. Depending on the location, a run can be between 5-7km long and is usually performed in around 60 seconds.
Safety line: an invisible, geographically defined line created to ensure that raceplanes remain more than a safe distance away from viewing locations and other key areas.
Stall: a wing stall. In simplest terms, due to the raceplane’s angle of attack exceeding a critical angle with the surrounding airflow, the wings can momentarily produce less lift, and on top of that, drag is increased. Wing stalls negatively impact the final run time.
Telemetry: the process by which data – like the raceplane data collected by the PRU – is collected and transmitted for remote monitoring by the judges in Race Control and the team tacticians who analyse flight lines. “We need to look at the telemetry data” is a familiar refrain when pilots are asked what went wrong in a run.
Track Limit Line: an invisible line defining the race box that surrounds the racetrack and that the plane shall not leave during a run to avoid a penalty. Taking the Track Limit Lines into account is a key task for tacticians.
Track optimisation: the tacticians’ raison d’être – it is why they exist! Track optimisation is the process of finding the racing line that will result in the lowest possible time given any particular conditions.
Vertical Turning Manoeuvre: the point where a pilot turns the raceplane when reaching one end of the track. The classic image of a Red Bull Air Race Vertical Turning Manoeuvre is a nearly pure vertical pull-up followed by a reverse roll, but at some racetracks it can also be a less extreme, vertically tilted turn, or sometimes the pilot may even choose to do a flat turn. The point is to get from one gate to the next in the fastest way possible, taking the three-dimensional racetrack into account.