Abstract: A method for an aircraft may include determining a transition from an airplane mode to a helicopter mode for a propulsion system of the aircraft, wherein the propulsion system comprises a plurality of rotor blades; determining whether a descent rate condition is satisfied, wherein the descent rate condition is associated with a maximum allowable descent rate for the aircraft; and controlling a collective pitch angle for the plurality of rotor blades based on the descent rate condition.

Abstract: A quad tiltrotor aircraft has a longitudinally extending fuselage with forward and aft stations. A forward wing having first and second outboard ends extends laterally from the forward station. An aft wing having first and second outboard ends extends laterally from the aft station. First and second forward rotors are respectively coupled proximate the first and second outboard ends of the forward wing and are tiltable relative to the forward wing between vertical lift and forward thrust orientations. First and second aft rotors are respectively coupled proximate the first and second outboard ends of the aft wing and are tiltable relative to the aft wing between vertical lift and forward thrust orientations. The forward rotors are higher disk-loading rotors than the aft rotors. The aft rotors are foldable in the forward flight mode to provide extended range for the quad tiltrotor aircraft.

Abstract: A method for an aircraft is provided in one example embodiment and may include determining a transition from an airplane mode to a helicopter mode for a propulsion system of the aircraft, wherein the propulsion system comprises a plurality of rotor blades; determining whether a descent rate condition is satisfied, wherein the descent rate condition is associated with a maximum allowable descent rate for the aircraft; and controlling a collective pitch angle for the plurality of rotor blades based on the descent rate condition.

Abstract: A quad tiltrotor aircraft has a longitudinally extending fuselage with forward and aft stations. A forward wing having first and second outboard ends extends laterally from the forward station. An aft wing having first and second outboard ends extends laterally from the aft station. First and second forward rotors are respectively coupled proximate the first and second outboard ends of the forward wing and are tiltable relative to the forward wing between vertical lift and forward thrust orientations. First and second aft rotors are respectively coupled proximate the first and second outboard ends of the aft wing and are tiltable relative to the aft wing between vertical lift and forward thrust orientations. The forward rotors are higher disk-loading rotors than the aft rotors. The aft rotors are foldable in the forward flight mode to provide extended range for the quad tiltrotor aircraft.

Abstract: An aircraft has a fuselage, a first rotor assembly having a first rotor hub and first rotor blades pivotably coupled to the first rotor hub and a second rotor assembly having a second rotor hub and second rotor blades pivotably coupled to the second rotor hub. The first and second rotor blades have deployed configurations extending generally radially from the fuselage and stowed configurations extending generally parallel with the fuselage. A sequencing cam, positioned between the first and second rotor hubs, is coupled to the second rotor blades. The sequencing cam has a retracted orientation when the second rotor blades are in the stowed configuration and an extended orientation when the second rotor blades are in the deployed configuration in which the sequencing cam props support arms of the first rotor blades preventing transition of the first rotor blades from the deployed configuration to the stowed configuration.

Abstract: An aircraft has a fuselage, a first rotor assembly having a first rotor hub and first rotor blades pivotably coupled to the first rotor hub and a second rotor assembly having a second rotor hub and second rotor blades pivotably coupled to the second rotor hub. The first and second rotor blades have deployed configurations extending generally radially from the fuselage and stowed configurations extending generally parallel with the fuselage. A sequencing cam, positioned between the first and second rotor hubs, is coupled to the second rotor blades. The sequencing cam has a retracted orientation when the second rotor blades are in the stowed configuration and an extended orientation when the second rotor blades are in the deployed configuration in which the sequencing cam props support arms of the first rotor blades preventing transition of the first rotor blades from the deployed configuration to the stowed configuration.