that doesn't appear to me to be the same thing as the multiple planes doing the crisscross patterns. this thread is long and i haven't read it all, but has anyone explained the difference between one plane with a con? chem? trail behind it as opposed to 2 and sometimes 3 crisscrossing over the same area for hours?
crisscrossing can be explained by planes bypassing navaid stations, or by planes who've filed flight plans "direct"... planes which use GPS, loran, ADF (including commerical AM radio stations), inertial navigation or other navigation systems that are independent of ground- based navaids.