I’m having a problem with a Raspberry Pi 3 using the latest PiAware image and connecting to wifi. I have no problem connecting to either my 2G or 5G network when I use an SD card with the NOOBS software, but when I insert the SC card containing PiAware, it fails to connect to wifi. It should be noted that when inserting the same SD card containing PiAware into an older Raspberry Pi 2, it connects to wifi no problem.
I had some problems with the country not being set and the pi3 refusing to connect.
It’s some new feature specific to the pi3 and stretch i believe. You might have to remove the piaware wireless options and use the guide here: Raspbian Stretch Headless Setup Procedure - Raspberry Pi Forums
Be sure to set the correct code for your country. If the country is not set the pi3 will not work.
Probably flightaware people need to introduce a country setting that sets the country.
Regarding the other answer: gateway and nameservers should be configured by DNS, not sure why that would help without a static ip.