A nacelle for an aircraft, comprising: a rotating part with propeller blades; a static part; a hydraulic actuation system, the hydraulic actuation system comprising: an actuator; a primary actuation arrangement to provide hydraulic fluid to control the actuator, wherein the hydraulic actuation system is configured to detect a fault in the actuator; a secondary actuation arrangement to provide hydraulic fluid to control the actuator in response to a detection of a fault in the actuator; wherein the actuator further comprises: a first chamber and a second chamber, and wherein the primary actuation arrangement controls the hydraulic fluid in the first chamber and the second chamber; and a third chamber, wherein the secondary actuation arrangement controls the hydraulic fluid provided in the third chamber; wherein the first chamber is configured to decrease pitch of the propeller blades; wherein the second chamber is configured to increase pitch of the propeller blades; and wherein the third chamber is configured to increase pitch of the propeller blades; wherein the primary actuation arrangement is provided in or on the static part and the secondary actuation arrangement is provided in or on the rotating part; characterized in that the secondary actuation arrangement comprises: an electrically powered motor; a hydraulic pump; and a secondary electro-hydraulic servo valve. a rotating part with propeller blades; a static part; a hydraulic actuation system, the hydraulic actuation system comprising: an actuator; a primary actuation arrangement to provide hydraulic fluid to control the actuator, wherein the hydraulic actuation system is configured to detect a fault in the actuator; a secondary actuation arrangement to provide hydraulic fluid to control the actuator in response to a detection of a fault in the actuator; wherein the actuator further comprises: a first chamber and a second chamber, and wherein the primary actuation arrangement controls the hydraulic fluid in the first chamber and the second chamber; and a third chamber, wherein the secondary actuation arrangement controls the hydraulic fluid provided in the third chamber; wherein the first chamber is configured to decrease pitch of the propeller blades; wherein the second chamber is configured to increase pitch of the propeller blades; and wherein the third chamber is configured to increase pitch of the propeller blades; wherein the primary actuation arrangement is provided in or on the static part and the secondary actuation arrangement is provided in or on the rotating part; characterized in that the secondary actuation arrangement comprises: an electrically powered motor; a hydraulic pump; and a secondary electro-hydraulic servo valve. an actuator; a primary actuation arrangement to provide hydraulic fluid to control the actuator, wherein the hydraulic actuation system is configured to detect a fault in the actuator; a secondary actuation arrangement to provide hydraulic fluid to control the actuator in response to a detection of a fault in the actuator; wherein the actuator further comprises: a first chamber and a second chamber, and wherein the primary actuation arrangement controls the hydraulic fluid in the first chamber and the second chamber; and a third chamber, wherein the secondary actuation arrangement controls the hydraulic fluid provided in the third chamber; wherein the first chamber is configured to decrease pitch of the propeller blades; wherein the second chamber is configured to increase pitch of the propeller blades; and wherein the third chamber is configured to increase pitch of the propeller blades; wherein the primary actuation arrangement is provided in or on the static part and the secondary actuation arrangement is provided in or on the rotating part; characterized in that the secondary actuation arrangement comprises: an electrically powered motor; a hydraulic pump; and a secondary electro-hydraulic servo valve. a first chamber and a second chamber, and wherein the primary actuation arrangement controls the hydraulic fluid in the first chamber and the second chamber; and a third chamber, wherein the secondary actuation arrangement controls the hydraulic fluid provided in the third chamber; wherein the first chamber is configured to decrease pitch of the propeller blades; wherein the second chamber is configured to increase pitch of the propeller blades; and wherein the third chamber is configured to increase pitch of the propeller blades; wherein the primary actuation arrangement is provided in or on the static part and the secondary actuation arrangement is provided in or on the rotating part; characterized in that the secondary actuation arrangement comprises: an electrically powered motor; a hydraulic pump; and a secondary electro-hydraulic servo valve.