FIELD

The present disclosure relates generally to the field of aircraft, and more specifically to shifting a center of gravity of an aircraft based on a change in mobility phase of the aircraft.

BACKGROUND

In different types of aircraft, the desired location of the aircraft's center of gravity —i.e., a balance location of the aircraft's mass, may depend on a variety of factors including a mobility phase in which the aircraft is operating. As one example, for an aircraft designed to operate in a hover mobility phase (e.g., a helicopter), a center of gravity of the aircraft is preferably collocated with a center of lift of the aircraft—i.e., a balance location of the aircraft's vertical thrust that enables hovering. By collocating the center of gravity with the center of lift, a load of the aircraft is equally balanced between all propulsors (e.g., rotors) of the aircraft, and the aircraft is able to provide power-efficient hovering without any one propulsor being loaded more than any other propulsor.

As another example, for an aircraft designed to operate primarily in a cruising mobility phase (e.g., a passenger jet), a center of gravity of the aircraft is preferably positioned forward in a longitudinal direction from a center of pressure of the aircraft—i.e., a balance location of upward aerodynamic loads on the aircraft in forward cruise flight. By positioning the center of gravity ahead of the center of pressure, positive static stability (i.e., static margin) is achieved while in the cruising mobility phase. Accordingly, the balance of aircraft mass and aerodynamic forces in a statically stable aircraft operates to passively reject small disturbances to pitch, thereby increasing stability and efficiency per flight phase.

SUMMARY

According to one aspect of the present disclosure, an apparatus for shifting a center of gravity of an aircraft is disclosed. The apparatus includes a propulsion component, a moveable ballast component, and an assembly configured to translate the moveable ballast component. The propulsion component is configured to assist in transitioning the aircraft between a first mobility phase and a second mobility phase. The assembly is configured to translate the moveable ballast component between an aft position and a forward position of the aircraft based on the aircraft transitioning between the first mobility phase and the second mobility phase to shift the center of gravity of the aircraft along a longitudinal axis of the aircraft.

The features, functions, and advantages that have been discussed can be achieved independently in various embodiments or may be combined in yet other embodiments, further details of which can be seen with reference to the following description and drawings.

