Is there an event to configure alerts if the “estimatedarrivaltime” has changed? I had thought it could be the e_eta.
I’m sorry, but there isn’t an alert trigger based on ETA change while the flight is enroute. The e_eta is the minutes_out option when setting up an alert.
An approximation in FlightXML could be set up in the alerts by configuring several minutes out alerts or by polling the FlightInfoEx endpoint using the faFlightID seen in the alert.
If a requirement is to have every possible eta update pushed as it happens then Firehose may be a better suited product.