Solo barrel rolls maybe more gentlemanly affairs Phantom Driver but formation ones are a different kettle of fish. My personal experience is five line abreast in an aircraft with poor throttle response - for the Black Arrows there would have been better throttle response from the Avon but 3 out at the edge of the 16 diamond would have been hard work. The formation holding in the loop photographs, which I would guess are from a practice, is superb. My guess is that they flew the loop in big seven with everyone else in line astern on their individual leader. A great result, I wish I’d been there working rather than spectating as a nipper.