707 roll was quite impressive, although it was an aileron roll not a barrel roll. However Tex's description of it was not entirely accurate. It wasn't (and couldn't be) a 1g manouvre - if you stay level inverted, you are pulling -1g. In order to roll any aircraft through the inverted you would have to fly very close to, if not completely, ballistically whilst inverted to avoid an excessive ROD and airspeed, or pushing -ive g, ie at or close to 0g. To maintain +1g inverted requires a hell of a pull through (the equivalent of a 60deg bank level turn), which would have you near the vertical before you had completed the first 180deg of roll. You would then need considerably more than +1g to pitch up and recover. In a barrel roll, since you pitch up to about 30-45deg first (thereby instantly pulling more than 1g), you can maintain 1g over the top, but in the second half you would have to pull much more to recover to level flight - ergo neither can ever be a '1g manouvre'. The only manouvre you can MAINTAIN 1g throughout is straight flight! (not straight and LEVEL as obviously you can maintain 1g in a climb or descent)
Does this make sense? It did in my head, at least!!
16B