Old 10th Aug 2018, 11:14
  #7 (permalink)  
Join Date: Sep 2007
Location: London
Posts: 484
A very interesting area as I have been spending several hours trawling data from FR24 for some work I am doing trying (there must be a better way of accessing data but it would cost). They state

Disclaimer: The information provided on this page is a compilation of data from many different sources including flight scheduling systems, airline booking systems, airports, airlines and other third-party data providers. The data is provided as is, there are no guarantees that the information is fully correct or up to date. Changes and errors may occur. Therefore Flightradar24 cannot be held liable either for the accuracy of the information or for ensuring that the information is up to date at all times. Some of the flights presented may be charter, cargo, ambulance or other types of flights not available for passenger travel.

I assume from the above that apart from the obvious source of transponders they access airline websites or possible their computer system directly. I believe that the Schiphol enthusiasts site uses a webcrawler.

I have generally found that info on passenger flights is much more accurate that than for cargo where there are often duplicate entries (a middle sector of a triangular flight may have the flight number of both the inbound & outbound sector) & Fed Ex & UPS can be hit or miss.

Errors I have found include:
The flight apparently operating from a by nearby airport. Have a look at flight UA1917 in 18th July (the day I was looking at). The Denver QQH - San Diego sector appears to be a wobbly.
- Diversions that appear not to have happened. Have a look at flight DL273 LIS - JFK - SFO on 8th Aug. The first sector apparently diverted to SFO but not according to the replay. - Obviously a glitch on the system.
- Getting the direction of the flight wrong (quite easy when inbound and outbound legs have the same number). An example DL1865 on 18th July. It shows two FLL - DTW sectors but the first one is actually the opposite direction (and the landing time is incorrect).

Unfortunately airline websites do not give historic data so I can't double check more than about 24 hours after the event. I used to use Flightstats to cross check but they now charge - I don't know if its worth taking out a subscription.

Its an interesting area and I'd love to hear from experts.

Last edited by Peter47; 10th Aug 2018 at 18:43. Reason: Add an example
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