The loop, first flown in 1913, is one of the basic and most elegant figures in aerobatics. Andy Hill’s Hunter at Shoreham was apparently performing a quarter clover, a more complicated variation.
In an ordinary “inside” loop, you aim to carve a perfect vertical circle without deviating from your axis — turning left or right. You co-ordinate the forces of gravity and power, lift and drag while varying pressure on the stick that controls pitch via the elevators on the tail. Touches on the ailerons — sideways movement on the stick — and the rudder pedals keep you in balanced flight.
With your eyes firmly on outside references to keep straight, you pull as you enter a climb. All but the highest-powered aircraft slow down as the g-force pins down your body.
As you arrive at the top upside down you relax back-pressure on the stick. The ground fills the windshield as you begin pulling again, easing back the throttle to avoid overspeed, and return to horizontal flight. You fly out in the same direction as you started and put power back on. Losing too much altitude is no problem if the loop is performed high enough.
In the quarter clover version performed at Shoreham, the aircraft ends the loop flying at right-angles to its course of entry. You begin a roll during the pull-up when the nose is about half way to becoming vertical. Rolling left or right, you aim to be heading 90 degrees from the course of entry when coming over the top, then descend.
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For reasons that have yet to be established, Mr Hill’s Hunter remained in a rapid descent, hitting the ground pitched in a level attitude but still far from re-established in horizontal flight.
• Charles Bremner has been a pilot for 30 years and has performed aerobatics