Abstract: A method of automatically determining a flight trajectory of a vertical take-off and landing aircraft having vectorable propulsion can be used to improve flight efficiency. The method includes receiving one or more aircraft flight constraints, inputting the aircraft flight constraints to a trajectory planning algorithm to determine a minimum energy aircraft transition trajectory, and outputting a control schedule to fly the aircraft to along the flight trajectory.

Abstract: A method of determining a flight trajectory of a vertical take-off aircraft (10) having vectorable propulsion (30, 32). The method comprises: receiving one or more aircraft flight constraints; inputting the aircraft flight constraints to a trajectory planning algorithm to determine a minimum energy aircraft transition trajectory; and outputting a control schedule to fly the aircraft (10) to the flight trajectory.

Abstract: An aircraft defining longitudinal, lateral and vertical directions the aircraft comprising: a main wing and a tail, each being pivotable about the lateral direction; a plurality of main propellers mounted to the main wing, and configured to pivot with the main wing; at least one cruise propeller mounted to the tail, and configured to pivot with the tail; the main propellers defining a swept disc area (Adisc), and the main wing defines a wing area (Awing); wherein a ratio of the disc swept area to the main wing area (Adisc:Awing) is between 1 and 2.

Abstract: An aircraft defining longitudinal, lateral and vertical directions the aircraft comprising: a main wing and a tail, each being pivotable about the lateral direction (B); a plurality of main propellers mounted to the main wing, and configured to pivot with the main wing; at least one cruise propeller mounted to the tail, and configured to pivot with the tail; each main propeller being stowable from a deployed position to a stowed position; wherein each main propeller has a fixed pitch, and each cruise propeller has a variable pitch.

Abstract: A rotor arrangement including: a rotor stage having an annular array of rotor blades each blade having a tip; a casing that surrounds the rotor stage and defines a clearance between the tips and the casing; and an over tip leakage measurement system including a multi-hole total pressure probe mounted to a stationary component downstream of the rotor stage; the probe arranged such that the axis of at least one of the holes is substantially aligned with an expected flow direction from the rotor stage.

Abstract: A rotor arrangement including: a rotor stage having an annular array of rotor blades each blade having a tip; a casing that surrounds the rotor stage and defines a clearance between the tips and the casing; and an over tip leakage measurement system including a multi-hole total pressure probe mounted to a stationary component downstream of the rotor stage; the probe arranged such that the axis of at least one of the holes is substantially aligned with an expected flow direction from the rotor stage.