FlightAware Discussions

Unusual flight data

Recently I flew as a passenger from Mexico City to San Jose in Costa Rica. The flight was quite unusual, firstly was very bumpy but it happens when you are up, secondly I experienced speed reduction and acceleration. A month after I decided to investigate and this is what I found:

Can anybody advise if that was normal?

Many thanks,


The varying speed in the second half of the flight looks like it is due to switching between several different radar sites while the flight was out of range of our terrestrial ADS-B network. The different radars measured the aircraft speed/heading differently (radars are not as accurate as ADS-B, particularly at longer ranges) which produces the varying speeds in the tracklog. There’s actually a similar effect in the position track itself, it’s just less obvious due to the smoothing of the track that we do for display.

Many thanks for the answer, it make sense.