Boom has conducted three rounds of wind tunnel testing using scale models and various elements of the airframe and engines. With the milestones it has attained during its preflight testing phase, Boom has recognized significant gains in efficiency over previous aircraft, such as Concorde. One key design challenge to Concorde lay in its engine inlets: No jet engine can intake air at supersonic speeds, so engineers must create intakes that slow the air down from Mach 2.2 to Mach 0.5 or in that range. Boom reported at its press conference in Paris that it saw efficiency gains of up to 5% over Concorde’s intakes during a phase of its wind tunnel proving. Software-controlled compression ramps position shockwaves precisely, allowing for improved operations throughout the flight envelope.