MLAT after power failure not ok?

Who can help?

two days ago my rasperry pi II restarted after power failure and then mlat no longer works for me !?
Everything is ok until the failure!

I have not changed anything

Here my log´s:

[2017-12-13 16:51 CET] ====== successful login from piaware 3.5.3 from ******** ======
[2017-12-13 16:51 CET] logged in to FlightAware as user hirntodhd
[2017-12-13 16:51 CET] my feeder ID is 48************************
[2017-12-13 16:51 CET] site statistics URL:
[2017-12-13 16:51 CET] multilateration data requested
[2017-12-13 16:51 CET] Starting multilateration client: /usr/lib/piaware/helpers/fa-mlat-client --input-connect localhost:30005 --input-type dump1090 --results beast,connect,localhost:30104 --results beast,listen,30105 --results ext_basestation,listen,30106 --udp-transport
[2017-12-13 16:51 CET] mlat-client(5360): fa-mlat-client 0.2.10 starting up
[2017-12-13 16:51 CET] mlat-client(5360): Using UDP transport to port 5007
[2017-12-13 16:51 CET] mlat-client(5360): Listening for Beast-format results connection on port 30105
[2017-12-13 16:51 CET] mlat-client(5360): Listening for Extended Basestation-format results connection on port 30106
[2017-12-13 16:51 CET] mlat-client(5360): Input connected to localhost:30005
[2017-12-13 16:51 CET] mlat-client(5360): Input format changed to BEAST, 12MHz clock
[2017-12-13 16:51 CET] mlat-client(5360): Beast-format results connection with ::1:30104: connection established
[2017-12-13 16:51 CET] mlat-client(5360): Accepted Extended Basestation-format results connection from ::ffff:*********:8523
[2017-12-13 16:52 CET] 243408 msgs recv’d from dump1090-fa (1696 in last 5m); 242935 msgs sent to FlightAware
[2017-12-13 16:57 CET] 245135 msgs recv’d from dump1090-fa (1727 in last 5m); 244662 msgs sent to FlightAware
[2017-12-13 17:02 CET] 246655 msgs recv’d from dump1090-fa (1520 in last 5m); 246182 msgs sent to FlightAware
[2017-12-13 17:06 CET] mlat-client(5360): Receiver status: connected
[2017-12-13 17:06 CET] mlat-client(5360): Server status: clock unstable
[2017-12-13 17:06 CET] mlat-client(5360): Receiver: 998.5 msg/s received 216.5 msg/s processed (22%)

pi@flight145:~ $ piaware-status
PiAware master process (piaware) is running with pid 485.
PiAware ADS-B client (faup1090) is running with pid 739.
PiAware mlat client (fa-mlat-client) is running with pid 5360.
Local ADS-B receiver (dump1090-fa) is running with pid 476.

dump1090-fa (pid 476) is listening for connections on port 30005.
faup1090 is connected to the ADS-B receiver.
piaware is connected to FlightAware.

dump1090 is producing data on localhost:30005.

The unstable clock is referring to the receiver that have bad timing information. There are multiple reasons that the timing information is off. Here are some of them:

  1. USB cable is dropping information. Usually affected by low quality USB extension cables. Try directly connecting the receiver to the raspberry pi’s USB port.
  2. Power supply is not supplying enough power. You can try another 5V USB supply and see if this fixes the timing.
  3. The receiver location is off. The server side MLAT Timing calculations depend on your receiver location. Go to your FlightAware my-ADSB page and set your location with the gear icon.
  4. The receiver dongle is dropping information. Maybe try another receiver dongle.
  5. The clock chip on the receiver dongle is bad. Try another receiver dongle.

hi david,

i have no usb cable, my flightaware stick is conectet directly.
but I have replaced the power supply without success!

after I restarted my raspberry three times in a row, 2 times mlat was gone after 5 minutes !!! at 3 times it works well again?!

mlat works now over 30 minutes without error??? …strange…

unfortunately no success again mlat error. tested a new raspberry …
same error: mlat-client (970): Server status: clock unstable!

the error must be on the “FlightAware” stick, or possibly on the connection to the mlat server. will try again to reinstall everything, if that does not work, I turn off here. The hobby becomes too expensive and too time-consuming.

You’re using a custom setup. I would suggest using a spare SD card and installing the stock installation provided by Flightaware before buying anything. Download it from: Follow the directions here: Right now, you have MLAT disabled. Any testing will be unproductive in that state. Once you have a good known software configuration, you will have a better chance of finding the problem.

1 Like

yes that is it!!!
no hardware problem found!!!

i install the new SD Card Version… running perfekt! thx :+1:


  1. sd card or software problem, install a new version and test again!