Abstract: One embodiment is an aircraft including a fuselage; a wing connected to the fuselage; first and second booms connected to the wing on opposite sides of the fuselage; first and second forward propulsion systems attached to forward ends of the first and second booms; first and second aft propulsion systems fixedly attached proximate aft ends of the first and second booms; first and second wing-mounted propulsion systems connected to outboard ends of wings; and first and second wing tips fixedly connected to outboard sides of the first and second wing-mounted propulsion systems; wherein the first and second wing-mounted propulsion systems and the first and second wing tips are collectively tiltable between a first position when the aircraft is in a hover mode and a second position when the aircraft is in a cruise mode.

Abstract: One embodiment is an apparatus for inhibiting accidental contact by a human with a tail rotor connected to an empennage of an aircraft. The apparatus includes an inverted V-tail connected to an empennage of the aircraft forward of the tail rotor, the inverted V-tail stabilizer comprising a first V-tail stabilizer on a side of the empennage to which the tail rotor is connected and a second V-tail stabilizer on a side of the empennage opposite the side of the empennage to which the tail rotor is connected; and a shroud bar having a first end connected to an outboard end of the first V-tail stabilizer and a second end opposite the first end connected to the empennage aft of the tail rotor, wherein a horizontal distance from the shroud bar to the tail rotor is greater than a length of an arm of the human.

Abstract: One embodiment is an aircraft including a fuselage; a wing connected to the fuselage; first and second booms connected to the wing on opposite sides of the fuselage; first and second forward propulsion systems attached to forward ends of the first and second booms; first and second aft propulsion systems fixedly attached proximate aft ends of the first and second booms; and first and second wing-mounted propulsion systems connected to outboard ends of wings; wherein the first and second wing-mounted propulsion systems are tiltable between a first position when the aircraft is in a hover mode and a second position when the aircraft is in a cruise mode.

Abstract: One embodiment is an aircraft including a fuselage; a wing connected to the fuselage; first and second booms connected to the wing on opposite sides of the fuselage; first and second forward propulsion systems attached to forward ends of the first and second booms; first and second aft propulsion systems fixedly attached proximate aft ends of the first and second booms; first and second wing-mounted propulsion systems connected to outboard ends of wings; and first and second wing tips fixedly connected to outboard sides of the first and second wing-mounted propulsion systems; wherein the first and second wing-mounted propulsion systems and the first and second wing tips are collectively tiltable between a first position when the aircraft is in a hover mode and a second position when the aircraft is in a cruise mode.