Originally Posted by
pandaperth
Assuming you want to stick to AY (to maximise AAdvantage miles) - the longest flight is HEL-LIS at 2,092 miles. (BTW I don't see your HEL-ATH flight on the oneworld planner.)
AY flights like HEL-ATH (or HEL-MIA) in the past have been tourist specials on (I think chartered) 757s with, like, 29" seat pitch. IIRC they do NOT accrue FF miles on any program, including AY's. HEL-LIS may be one such - Frozen Finns Frolicking in Faro.