We're using FlightAware's Flight XML api, among other data sources. Their API is pretty decent and their data is complete for US inbound/outbound and domestic f

We're using FlightAware's Flight XML api, among other data sources. Their API is pretty decent and their data is complete for US inbound/outbound and domestic flights. They are also really responsive on the forums to questions and feature requests. See here: http://flightaware.com/commercial/flightxml/ http://flightaware.com/commercial/flightxml/