A system and method for detecting ice formation on the surface of an aircraft includes a small rotatable disc disposed on and flush with a surface of a aircraft wing and/or stabilizer and a DC motor for rotating the disc. The disc is rotated periodically and the peak current which is directly proportional to the torque required to break any ice is monitored. When the torque exceeds a pre-selected amount a warning is sounded in the cockpit. If the torque required to rotate the disc increases a second warning is given and the amount of ice accumulation is calculated. In one embodiment of the invention, a stall warning system is automatically modified to increase the margin to accommodate for the increase due to ice accumulation.