PaulSEA1 - I would think AA81 would be considered one flight/sector. I've booked AA90 DFW-ORD-LHR in my current RTW. It's just one coupon in my ticket. I maxed out the sectors based on single flight numbers and no mention was made that I would need an extra sector. So I guess that even if you have to change planes but it is one flight number it only counts as one sector.