Patent ID: 6140942
Filing Date: 2000-10-31
Classification: B64C,B64D

Abstract:
A method for sensing surface contamination on an aircraft, the aircraft having a control element with a control surface and control area, the control element being connected to a hinge, said method comprising the steps of:sensing a control surface hinge moment about the hinge;determining a control surface steady hinge moment coefficient by nondimensionalizing said control hinge moment by a control surface area, a dynamic pressure and a control surface chord length;calculating a value which is dependent upon said control surface hinge moment coefficient, wherein said value remains at a relatively constant point during uncontaminated surface conditions on the control surface, said value varying from said constant point if the control surface becomes contaminated, said value varying before reaching a critical point, whereby said critical point occurs at a level of unsafe surface contamination on the control surface; andcomparing said value of said control surface hinge moment coefficient against said relatively constant point to determine whether or not an unsafe control surface condition exists.