Question: can I get flight delay information using FlightInfoEx (xml2) or should I use xml3?

[faFlightID] => ASV522-1580667600-schedule-0000
[ident] => ASV522
[aircrafttype] => A321
[filed_ete] => 04:00:00
[filed_time] => 1580667600
[filed_departuretime] => 1580840400
[filed_airspeed_kts] => 335
[filed_airspeed_mach] =>
[filed_altitude] => 0
[route] =>
[actualdeparturetime] => 0
[estimatedarrivaltime] => 1580863200
[actualarrivaltime] => 0
[diverted] =>
[origin] => VVNB
[destination] => RKSI
[originName] => Noi Bai Int’l
[originCity] => Hanoi
[destinationName] => Incheon Int’l
[destinationCity] => Seoul (Incheon)
)

ps: filed_time not find describe in FlightXML2 Web Services

Several different statuses can be determined by comparing the time values. Several examples are listed here.