Hello J molk
May I ask what is the result if you were to manually construct the query URL by appending the parameters yourself and then see if it is resolvable on a web browser on the GeoEvent Server?
i.e. http://flightxml.flightaware.com/json/FlightXML2/SearchBirdseyeInFlight?parameter1=test¶meter2=t...
I see that the base URL needs authentication to access, so I am assuming you include that information in the Header Parameter Name:Value List field? Either way, it could be that the query string that is being added is either in a format that Geoevent cannot recognize or that it is in some way invalid.
Please see if you can test manually constructing the URL and then navigating to it in a browser. If that works to return the expected JSON, try seeing if you can use that URL as the value for the URL field in the input connector.
It would also be working double-checking that the MIME types included in the input connector are:
text/json, application/json
You can also check the Geoevent logs to see if any messages were logged for inaccessibility to the URL you provided.