This is a part of the dissertation on the preparation of the 22 aircraft Hunter loop, which Dave Edmondston very kindly sent me:
There followed an intensive period of training, first in formations of four led by the more experienced members of the aerobatic team in fairly basic manoeuvres, then moving in slightly larger numbers to take the skeleton of what was to become the 22-aircraft formation.
There was little problem in the centre strands of the formation, but there was those at the back on the wings. The sweepback of the Vic meant that those at the very back were so far back that they were still in effect climbing up to the top of the loop while the leader was accelerating down the other side and, unless the throttle was very carefully managed and the loop very straight, there was simply not enough power to guarantee to keep station. So the technique was devised that when the leader reached the top of the loop he would relax the 'g' for a few moments upside down until the back end caught up and then would tighten, pulling slightly more'g' on the way down. In those days, Artificial Horizons toppled at about 30 degrees of pitch so between 60 degrees and until the horizon appeared above your head it could be difficult to be sure you were doing a straight loop. So Roger borrowed an experimental, un-toppable Artificial Horizon from his friends at Farnborough, which meant that he keep the loop straight.
As a matter of interest we worked out that the maximum number of Hunters we could loop was probably 33, but we could never be sure that it would hold its shape all the way round every time. Take the 24 shape, add on an aircraft to each side of the Vic with one in line-astern on each, add a fifth in line-astern behind Nos 4 and 5, and you have it - but of course we never had the pilots to try it!
On 12 August we achieved the world record of 21 aircraft...... the first 22 formation was flown on 22 August, and then on 25 August we moved to Odiham for the Farnborough display, where we flew the formation twice daily until the start of show week
By way of a repeat performance, the mass formation was flown at Wattisham on 11 September 1958, the second performance for AOC-in-C, ACM Sir Thomas Pike, who had sanctioned the original routine.