Different Aircraft count in FA and FR24


I am new to having a ADS-B receiver running off a raspberry pi.

One thing I have noticed is that I am feeding the data data in FR24 as well as FA but I see that FR24shows more aircraft than FA for the same time period. At the moment FA shows 54 and FR24 shows 58. Any idea why this might be? I have tired searching but did not find anything.

Thanks for your time.

I saw the same thing when I was feeding FR24.

I’m also curious as to why.

It may have something to do with time delay. FA state there is around a 30 second delay and I can often see this.

The SkyView generated by PiAware seems spot on - see an aircraft approach on the map and it flies over. The FA map can be delayed.

The missing aircraft may be due to type of transmitter aircraft has as to whether it gets displayed on the map.


Unfortunately I don’t get to see a huge number of aircraft here, but in a 24 hour period there is seldom more than one aircraft difference between FR and FA.

Location is fairly important to hobby, being around 12 miles from Heathrow I see many at around 8000 feet so decent view.

It is nice to occasionally see the ones you are recording on the Pi.