I see that the definition of the ETA (Estimated Time of Arrival) according to Eurocontrol is:
- (SESAR) the time computed by the FMS for the flight arriving at a point related to the destination airport
- (ICAO) For IFR flights, the time at which it is estimated that the aircraft will arrive over that designated point, defined by reference to navigation aids, from which it is intended that an instrument approach procedure will be commenced, or, if no navigation aid is associated with the aerodrome, the time at which the aircraft will arrive over the aerodrome.
For VFR flights, the time at which it is estimated that the aircraft will arrive over the aerodrome.
However I do not understand what is the difference with the Estimated On-Block time. Would you be able to explain the difference please?