Equal Time Point

ETP and Point of No Return for long-range routes

Route

Total Route Distance

True Airspeed (TAS)

kts

Headwind (+) / Tailwind (-)

kts

GS Outbound450 kts

GS Return450 kts

Equal Time Point

ETP Distance1,000nm

ETP Position50.0% of route

Time to ETP2h 13m

Continue = Return2h 13meach way

2h 13m to continue = 2h 13m to return

DEP

ETP

DEST

The ETP marks the point where turning back takes as long as pressing on. Beyond the PNR, you no longer have the fuel to return - you are committed to the destination.