How are Tail Numbers logged?
We maintain our own database of American Eagle/Envoy flight tail numbers and we use an API connection to FlightAware and other data sources to add all daily flights to that database.
Tail numbers for historical flights and imported with FlashBack are sourced from the DOT. Unfortunately the DOT does not have data for 2017, Executive Airlines, maintenance flights, or international flights.
While we try to match as many tail numbers as possible there may be times where a tail number cannot be matched.