Hi
Further to my last post, ‘War in the Air’ Vol. III, Appendix XI has a copy of a March 1917 document ‘Fighting in the Air’ mentioning that “Machines of each group should leave the ground together and should arrive at the rendezvous in the correct formation of their group.” The ‘group’ is later defined as two or three machines, for both single and two-seat aeroplanes, these could then form formations of six to nine machines each group having its own sub-leader. So at this period two or three machines would be taking off together, from there it is probable that later flights of five or so aeroplanes would take off together.
Mike