How to find historical info for outside primary service area

I want to draw the schedule flight route for which you do not provide on time routes(such as sq827). I tried to find the current longitute and latitude, but both your webside and API cannot provide an accurate one.

Then, I tried to find the historical data. I cannot find from API. I have tried “decode flight route” which contains flights in your primary service area and no data for flights like MU5051(PVG-ICN).
However, on your website, I checked the same flight for the previous day which has a clear route.

Could you please tell me which fuction in your API can gave me the historical latitude and longitude data?

The decoding of planned route positions in FlightXML using DecodeRoute/DecodeFlightRoute only supports flights that utilize continental U.S. navaids at this time.

However, you can still use GetHistoricalTrack to retrieve the lat/lon positions of the actual flight path, with the limitation that flights outside of our primary coverage areas tend to have more gaps due to estimated positions. … ricalTrack