A rotor assembly (60, 360) for a gas turbine engine comprising: a rotatable hub (62, 362) including a main body extending along a longitudinal axis, and including an array of annular flanges (62B, 362B) extending about an outer periphery of the main body to define an array of annular channels along the longitudinal axis; an array of airfoils (66, 166, 266, 366) circumferentially distributed about the outer periphery, each one of the airfoils (66, 166, 266, 366) including an airfoil section (66A, 166A, 266A, 366A) extending from a root section (66B, 266B, 366B) received in the annular channels, the airfoil section (66A, 166A, 266A, 366A) extending between a leading edge and a trailing edge in a chordwise direction and extending between a tip portion (66C, 266C) and the root section (66B, 266B, 366B) in a radial direction, and the airfoil section (66A, 166A, 266A, 366A) defining a pressure side and a suction side separated in a thickness direction; and an array of platforms (370, 470) releasably secured to the hub (62, 362), wherein each of the platforms (370, 470) includes a platform body (388, 488), and the platform body (388, 488) is mechanically attached to the hub (62, 362), characterised in that: each of the platforms (370; 470) includes opposed rows of resilient support members (394, 494) that abut against adjacent airfoils (66, 166, 266, 366) of the array of airfoils (66, 166, 266, 366) to oppose movement of the respective airfoil section (66A, 166A, 266A, 366A) in the circumferential direction; and the airfoil section (66A, 166A, 266A, 366A) includes a metallic sheath (72, 172, 272, 372) that receives a composite core (74, 174, 274), and the core (74, 174, 274) includes first and second ligaments (76A, 76B) received in respective internal channels (72C, 72D, 172C, 172D) defined by the sheath (72, 172, 272, 372) such that the first and second ligaments (76A, 76B) are spaced apart along the root section (66B, 266B, 366B) with respect to the longitudinal axis. a rotatable hub (62, 362) including a main body extending along a longitudinal axis, and including an array of annular flanges (62B, 362B) extending about an outer periphery of the main body to define an array of annular channels along the longitudinal axis; an array of airfoils (66, 166, 266, 366) circumferentially distributed about the outer periphery, each one of the airfoils (66, 166, 266, 366) including an airfoil section (66A, 166A, 266A, 366A) extending from a root section (66B, 266B, 366B) received in the annular channels, the airfoil section (66A, 166A, 266A, 366A) extending between a leading edge and a trailing edge in a chordwise direction and extending between a tip portion (66C, 266C) and the root section (66B, 266B, 366B) in a radial direction, and the airfoil section (66A, 166A, 266A, 366A) defining a pressure side and a suction side separated in a thickness direction; and an array of platforms (370, 470) releasably secured to the hub (62, 362), wherein each of the platforms (370, 470) includes a platform body (388, 488), and the platform body (388, 488) is mechanically attached to the hub (62, 362), each of the platforms (370; 470) includes opposed rows of resilient support members (394, 494) that abut against adjacent airfoils (66, 166, 266, 366) of the array of airfoils (66, 166, 266, 366) to oppose movement of the respective airfoil section (66A, 166A, 266A, 366A) in the circumferential direction; and the airfoil section (66A, 166A, 266A, 366A) includes a metallic sheath (72, 172, 272, 372) that receives a composite core (74, 174, 274), and the core (74, 174, 274) includes first and second ligaments (76A, 76B) received in respective internal channels (72C, 72D, 172C, 172D) defined by the sheath (72, 172, 272, 372) such that the first and second ligaments (76A, 76B) are spaced apart along the root section (66B, 266B, 366B) with respect to the longitudinal axis.