Often seen at RAF Coningsby and of course many other places, the “E145” is effectively a staff transport plane that ferries support teams to and from other bases to look after military jets, among other assumed staff transport roles.
It is seen in action quite regularly so if you ever watch any footage on bases, you will likely see it taking off or landing.
The standard ERJ 145 jet is a “little” 50 seater is part of a “family” of aircraft that has origins in Brazil and is powered by hefty twin jet engines and classed as regional jet powered replacement for prop powered planes.
You can learn a lot more about here.
