Tiltrotor Aircraft having a Downwardly Tiltable Aft Rotor

A tiltrotor aircraft having a vertical takeoff and landing flight mode and a forward flight mode, the aircraft comprising:

• a longitudinally extending fuselage having an aft end;
• a wing extending laterally from the fuselage having first and second oppositely disposed wing tips distal from the fuselage;
• first and second tip booms respectively extending longitudinally from the first and second wing tips, the first and second tip booms each having forward and aft ends;
• first and second forward rotors respectively coupled to the forward ends of the first and second tip booms, the first and second forward rotors reversibly tiltable between a vertical lift orientation, wherein the first and second forward rotors are above the respective first and second tip booms, and a forward thrust orientation, wherein the first and second forward rotors are forward of the respective first and second tip booms;
• first and second tail assemblies respectively coupled to the aft ends of the first and second tip booms, the first and second tail assemblies operating in an upwash in the forward flight mode;
• an aft rotor coupled to the aft end of the fuselage, the aft rotor reversibly tiltable between a vertical lift orientation, wherein the aft rotor is below the fuselage, and a forward thrust orientation, wherein the aft rotor is aft of the fuselage;
• a flight control system operably associated with the forward rotors and the aft rotor, the flight control system operable to independently control each of the rotors including transitions between the vertical lift and the forward thrust orientations;
• and
• a power system including at least one electric motor operably associated with each of the rotors and an electric energy source.