Delay in actual departure from airports.


Flightaware has a huge delay, like 20 minutes or so. from when an airplace actually departs the runway and when it lands. Using other systems, the delay is very short. Why does FA continue to put in such a huge delay?


The amount of delay that FlightAware adds to the process is very small - there’s 3 sources that contribute to the delay:
Time it takes the controller/FAA to mark the event (like a departure) as occurred - typically 0-2 minutes.
FAA mandated delay - 5 minutes.
FlightAware processing - typically a few seconds.

So in total we typically have departures on our site 5-7 minutes after the event occurred. For airlines we have direct feeds from the delay is typically less than a minute, since there’s no FAA mandated delay.

Here’s some recent departures and the times they were marked:
2011-06-20 20:42:21 | JBU633/A320 departed KBOS @ 04:37PM EDT for KSFO ETA 07:20PM PDT
2011-06-20 20:42:16 | BLOCKED/BLK departed KBNA @ 03:37PM CDT for KMSP ETA 04:32PM CDT
2011-06-20 20:42:15 | N472QS/GLF4 departed KMDW @ 13:37 PDT for KBCT ETA 15:52 PDT
2011-06-20 20:42:14 | POE389/DH8D departed CYTZ @ 16:35 EDT for KMDW ETA 17:07 CDT
2011-06-20 20:42:14 | EJA846/C560 departed KPHL @ 16:37 EDT for KTTN ETA 16:18 EDT
2011-06-20 20:42:13 | AAL1371/MD83 departed KORD @ 03:41PM CDT for KDFW ETA 05:22PM CDT
2011-06-20 20:42:11 | SWA23/B733 departed KMSY @ 03:36PM CDT for KBHM ETA 04:26PM CDT

So you can see most of the departures are 5 minutes delayed, except for the Porter flight which was 7 minutes delayed, and the American flight which was 1 minute delayed (direct feed).

Now if a flight picks up their clearance in the air, it may be 15 minutes from actual departure until we show it on the flight (10 minutes before they call ATC, then 5 minute FAA delay). But every flight tracking site should have the same delay for that flight.