Filed Speed no longer correct?


The “Filed Speed” used to match what I filed on my flight plan; but more often than not does not match anymore. I’ve noticed this on other aircraft, too. Filed speed should be the expected True Airspeed, and therefore is not subject to wind. It appears that some algorithm is trying to apply a wind adjustment to the filed speed to get an estimated ground speed. Is this being done by the data source or by FlightAware?

I personally would prefer to see the speed that was actually filed on the flight plan, not some wind adjusted estimation. If that isn’t possible (for example, the data as received by FA already has some unknown adjustment applied), then this field should be identified as “Estimated Speed” or similar, but certainly not “Filed Speed,” because it isn’t.

Thanks for a great site, FlightAware!


Can you provide examples with the flight identifier, date, origin, destination, and the speed filed in the flightplan?


One of my aircraft: N26CX: Most frequently file at 160 KTAS.
Flights prior to mid-May all show my actual filed speed (dates: 3/29, 3/31, 4/5, 4/8, 5/7)
May 24 it shows 177, when I actually filed 165 or 170 because of high altitude (I don’t remember which, but I round off to nearest 5 knots and never file over 170).
June 2, shows 133 for first leg and 135 for second when filed 160 for both (bad headwinds that day!)
June 30, shows 160, and that was what was filed.
July 7, shows 162, filed 160.
July 12, shows 150, filed 160.
July 15, shows 160 for first leg and 158 for second, filed 160 for both.
July 27, shows 164, filed 160.
July 29, shows 151, filed 160.

A friend’s aircraft: N52797. Always files 135 KTAS. Half of recent flights correct, others range from 126 to 150 knots.


It looks like we’re clobbering it, I’ve filed a bug against the flight tracking team to not do that.