ETP

ETP (Equal Time Point) is the point along the flight route from which the flying time to two designated diversion airports is equal, considering wind and aircraft performance (often with one engine inoperative). The ETP is critical for oceanic and remote area flight planning.

Flight crews calculate multiple ETPs for different scenarios: engine failure, depressurization, and medical emergency, as the optimal diversion airport may differ for each case. ETOPS operations require careful ETP planning to ensure adequate fuel for diversion.