Lockheed Falcon HTV3X Blackswift

The Blackswift was a proposed aircraft capable of hypersonic flight designed by the Lockheed Martin Skunk Works, Boeing, and ATK.

The USAF states that the "Blackswift flight demonstration vehicle will be powered by a combination turbine engine and ramjet, an all-in-one power plant. The turbine engine accelerates the vehicle to around Mach 3 before the ramjet takes over and boosts the vehicle up to Mach 6."