A bumper bearing assembly for a gas turbine engine, the bumper bearing assembly comprising: a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines a first bearing seat; and a first bumper bearing connected to the bearing housing by a first spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the first bumper bearing is configured to apply the level of radial spring stiffness of the first spring against a rotor with the first bumper bearing spaced apart from the first bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the first bumper bearing seated against the first bearing seat, wherein the bearing housing further defines a second bearing seat, the bumper bearing assembly being characterised in that it further comprises: a second bumper bearing opposed to the first bumper bearing and connected to the bearing housing by a second spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the second bumper bearing is positioned to apply the level of radial spring stiffness of the second spring in a second radial direction opposed to the first radial direction against the rotor with the second bumper bearing spaced apart from the second bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the second bumper bearing seated against the second bearing seat, wherein each of the first and second bumper bearings is individually tuned so the first and second bumper bearings differ from one another in respective level of radial spring stiffness of the bearing housing. a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines a first bearing seat; and a first bumper bearing connected to the bearing housing by a first spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the first bumper bearing is configured to apply the level of radial spring stiffness of the first spring against a rotor with the first bumper bearing spaced apart from the first bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the first bumper bearing seated against the first bearing seat, wherein the bearing housing further defines a second bearing seat, the bumper bearing assembly being characterised in that it further comprises: a second bumper bearing opposed to the first bumper bearing and connected to the bearing housing by a second spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the second bumper bearing is positioned to apply the level of radial spring stiffness of the second spring in a second radial direction opposed to the first radial direction against the rotor with the second bumper bearing spaced apart from the second bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the second bumper bearing seated against the second bearing seat, wherein each of the first and second bumper bearings is individually tuned so the first and second bumper bearings differ from one another in respective level of radial spring stiffness of the bearing housing.