A landing gear assembly, having an electromechanical device for actuating the landing gear and locking and releasing device, includes: a rotary actuator acting on the assembly at the hinge point, having a rotary electric motor connected to an actuating arm, to rotate the assembly around a respective actuation axis with an interconnection so that, in case of power supply failure, the actuator is free to rotate dragged by the assembly by free fall; and a linear actuator, integral to the assembly and movable therewith, and which includes a rotary electric motor and a cam mechanism to transform rotary motion of the motor into an axial motion of a locking pin. The actuation axes of the rotary actuator and of the linear actuator are parallel, and the rotation axis of the rotary electric motor of the linear actuator coincides with the linear actuation axis of the locking pin.