I need to get those statuses in the API - which method should I use?
The results of FlightXML3 FlightInfoStatus returns a human readable status message. It doesn’t contain an exact match for these messages, but can be useful to pass through as a display value. However, passenger states like “boarding” will not be represented.
Otherwise, using the times present in FlightInfoStatus, with the include_ex_data=true paramater, can be used to derive states that can match up with the listed statuses.