FlightAware Discussions

Total Aircraft Discrepancy?

Is there an accurate way to check the number of total aircraft seen in a given period in PP and FA? It seems I had discrepancies since the end of November in total aircraft seen in PP and FA. I have sampled say a 20 minute period on different days, by going to PP aircraft view and counting as new aircraft are added to the list. While also in FA counting the aircraft added in the aircraft seen column in the same period. A few days ago in a slow 20 minute period I had 45 aircraft added in PP, while FA showed 20 (waiting for FA to update about 5 minutes later after the 20 minute period ended in PP). In a 1 hour sample period, PP showed 186 to 55 in FA. Also in the first 2 months of feeding FA I averaged around 1300 total aircraft a day, which is down to around 600 a day now, while in PP my aircraft seen log totals have remained basically unchanged.
So any ideas whats going on anyone?
Craig Cook

Could the difference be FA only counting those with Lat/Lon values with PP counting everything?

Those we send without Lat/Lon are probably useless to them for mapping possibilities.


I posted a similar query in Planeplotter Yahoo Group - this was Bev’s reply:

At 23:53 31/12/2013, you wrote:

Bev would it be possible to show the cumulative number of flights as
well as reports in the user stats?

"PlanePlotter…File…Report…Setup report format.
Set "Automatic reports at intervals of 0 minutes"
Set Files renamed “daily”.
Check “Create daily first/last database” and “Report only local aircraft”.

When the program has been running for a while, select Review…Report
database and select the daily SQB file.
You will see a text file in Notepad showing one entry for each unique
flight (meaning combination of airframe and flight number).
The number of lines is the number of unique flights.


Thanks Bev,
That’s how I have had my logging set up since I started using PP. That said, I had 1639 aircraft in my log for yesterday(12Jan2014) in PP, while my FA stats show:
Date Aircraft Seen Positions Reported
2014-01-12 613 17,892

Would say there is a pretty good discrepancy. I realize there are some duplicate hexs copied in the PP log due to it posting to the log without a flight number and then reposting with the flight number in some cases and such. It would seem that FA isn’t getting or processing all my PP data. Any having a similar problem?

Thanks again,
Craig Cook

My PP report is set up slightly differently as it currently logs in one minute intervalls not continoulsy as Bev recommends.
But still the FA numbers are significantly lower than those of PP.

On the 11.1 : PP=3132 <-> FA=2405
On the 12.1 : PP= 4106 <-> FA=2765

The difference beween FA and PA increased significantly after the chnages in Mid-December which caused a large reduction in the numbers reported for many feeders.

I see a lot of A/C on both trips e.g. Emirates flying Dubai-London and some time later the return flight London-Dubai.
This means same Hex code but different flight numbers.
Could it be that FA sees this as one plane ?
PP sees this a two unique flights.

I will now set my PP reports as Bev recommended and compare again.


Edit (with Bev’s report settings) :
On the 14.1 at 20:50 CET : PP = 2645 <-> FA = 2401

Receiver : Transponder Mouse via PP.
Location : near EDLW
Rec ID : 217

Done a check for today’s flights so far (times are UTC) figures are cumulative.

@ 07:36 FA 170 PP 210 flights (81%)
@ 11:42 FA 481 PP 524 flights (92%)
@ 19:45 FA 813 PP 862 flights (94%)
@ 23:59 FA 922 PP 968 flights (95%)

Receiver is RTL dongle and RTL1090 software feeding Planeplotter
Location mid Wales, UK. Receiver ID #287.

Thanks to all who have replied. My problem still persists as the below stats indicate.

14Jan2014 FA=597 PP=1573
15Jan2014 FA=113 PP=343 as of 0400z.

Craig Cook

Hi Craig
Have you inspected your daily log in detail to see how many flights are duplicated?
My log of 14 Jan shows 1536 lines but in 50% of cases there is a log for the same airframe with no flight number due to it not being transmitted in some messages (or the RTL1090 software not decoding it?) Examination showed there to be 1006 individual flights as against a figure of 945 in the FA stats.

From the log I can’t distinguish which aircraft are reporting positions but FA stats indicate that 754 of the 945 were positional so I don’t think this is the reason for the discrepancy.

Yes, I have inspected my daily logs, I average about a 28% duplicate rate. So 14Jan2014 PP=1573 minus the dupes would be 1133. FA=597. Not very good.

I did a 15 minute test a few minutes ago. Waited for FA to update, noted the aircraft seen in the personal stats section and then counted as PP added new aircraft (in aircraft view), watching for any duplication and compared. PP=40, FA=14 (making sure to wait for FA stats to update).

Also still trying to figure out why after two months of feeding FA with a pretty steady daily average of aircraft seen, that in one day it was cut by more than 50% and has stayed that way. The period of the drop happens to correspond with the busiest time of the year here.

Anyway, there appears to be a problem that I can't solve. I was hoping for some input from FA maybe as well as to what to do or to tell me what I have done wrong, like maybe I'm interpreting the stats wrong. 

 Again, thanks to all for your input.

Craig Cook