The invention relates to an axial flow turbine and method of operating thereof. The turbine comprises a last stage of rotating blades located towards a downstream end of the turbine having a distal region at an end of the airfoil of the blades. A monitoring control system has at least one sensor in the distal region of at least one last stage blade for measuring at least one physical property of the airfoil and a control element that is capable of influencing at least one physical property of the distal region. The control system further includes a controller that adjusts the control element based on at least measured physical property so by controlling the at least one physical property.