I’ve seen this vehicle has been put in HW2! Do you think that as it looks like a falcon, the AV-49 is similiar to it?
Doubt it, the AV-49 is a completely new vehicle (and one new enough that it has a whole set of armor being designed to be used with it).
That, and AV indicates “attack VTOL”, whereas the Nightengale is obviously based on the Falcon, which is a helicopter (hence its designation UH-144, Utility Helicopter-144).