Why are "Unknown" aircraft entries in list?

I typed in tail N348MS which is aircraft WhiteKnight2 from Virgin Galactic. Here is the result which includes the WHK2 flights but also a number of “Unknown” aircraft sometimes a few minutes after the WHK2 flight (e.g., 14-Jun and 13-Jun) but also hours apart (e.g. 06-Jun). I am new to FlightAware and don’t know how to understand what the “Unknown” flight entries mean. All help replies appreciated!!!

Unknown indicates that there was not enough information to decode the messages. There was something active at the given times but the information was incomplete so no registration could be attached. This could have been a chase plane for the WHK2 flight or the flight itself ( different parts of the flight).

This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.