Red Arrows publicity will tell you that aerobatics is essential for training top-notch pilots. That may be true - but flying-circus-type entertainment goes back to the earliest days of flight. Seventeen-year-old Dolly Shepherd, known as the Parachute Queen, entertained crowds at London's Alexander Palace as early as 1904, suspended from a trapeze attached to a balloon. After the First World War many unemployed pilots earned a living performing aerial tricks at showgrounds - walking on wings, hanging upside down from the landing gear or transferring from one airborne plane to another.
The First Royal Airforce aerobatic team was formed in 1920 at RAF Hendon, the airfield where the RAF Museum now stands. Soon, every squadron wanted one. There were the Black Knights, The Tigers, the Blue Diamonds, the Firebirds, the Red Pelicans and the Yellowjacks. Costs rose until the RAF eventually streamlined them all in 1965 to create one full-time professional team of nine pilots plus a spare pilot and commentator on the ground.
Flying in formation was a skill pilots learned in the early days of air combat - where a single plane was vulnerable to attack, a pair could defend each other. But they would rarely fly as close as the Hawk jets on the Red Arrows team - on average 12 feet apart, and sometimes as close as eight.
The formation shape can be distorted if one plane, travelling at 350 mph, is two feet out of position. The pilots maintain their distances using the team leader or another aircraft as a "marker". When flying the "tango roll", in the shape of a capital "T", for example, the four pilots at the top of the "T" fly forwards while looking over their left or right shoulders to make sure they keep in line with each other.
While moving in and out of formation - including "arrow", "diamond nine", "apollo" (the shape of a rocket) and "big vixen" (a wide capital "V"), - the pilots also put their planes through the rolls, swoops and turns that are possible only if you push a plane to its limit.
Planes can "roll", in which the wings lead the plane around as if it were a spinning saucer, "pitch", where the nose goes up or down up to and including when the plane does a head over heels, or "yaw", where the tail moves to left or right to achieve change of direction - or combinations of all three.
Red Arrow moves include flying upside down, cutting away from each other at high speed (the Hawks have been adapted for increased acceleration), the "corkscrew", in which Red 7 rolls around Reds 6, 8 and 9, and "the goose", in which Red 8 flies head-on towards the front five aircraft (known as "Enid" after Enid Blyton's Famous Five), swoops underneath them and climbs to rejoin from behind. And all this, with red and blue dye added to the vaporising diesel that hits the jet exhaust behind the aircraft to create coloured smoke.
If you want a Red Arrows flypast of your own, it will set you back pound;6,000. But the cost of sending the Reds abroad is much higher. It is one that defence manufacturers often club together to meet, however, which is why the Red Arrows have been seen all over the world. One of the biggest audiences was a crowd of 650,000 in Lisbon, Portugal, in 1973.