Originally Posted by
scifi
Could be the same as 'Point of No-Return', but maybe taking into account the time needed to do the 180 turn.
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No, not even close ETP and PNR are two completely different things. ETP is a point between 2 diversion alternates, (or destination and diversion alternate) where the time to fly to either is the same, considering winds. PNR is the point beyond which you cannot return to your departure point. PNR is not really related to any ETP, and may be beyond your destination. Ie: on shorter legs with large fuel loads, you can return to your point of departure at any point including overhead your destination.
About the only correlation between PNR and ETP is that ideally your PNR should be beyond the ETP between your departure and destination.