The "mother ship" for the Soviet parasite fighter is actually a Boeing B-50, a development of the B-29. ; The black fighter that appears near the finale, taxiing on the parking ramp and behind the "mother ship" is a Northrop F-89 Scorpion.
In this context, the Boeing B-50 serves as the main aircraft for the Soviet parasite fighter, while the Northrop F-89 Scorpion is a secondary dark fighter that appears towards the end of the scene.