United States Patent no. 7,931,238, issued on April 26, was assigned to Bell Helicopter Textron Inc. (Fort Worth, Texas).

“Automatic Velocity Control System for Aircraft” was invented by Kenneth E. Builta (Euless, Texas) and Kynn J. Schulte (Arlington, Texas).

According to the abstract released by the U.S. Patent & Trademark Office: “A flight control system for an aircraft receives a selected value of a first parameter, which is either the airspeed or inertial velocity of the aircraft. A primary feedback loop generates a primary error signal that is proportional to the difference between the selected value and a measured value of the first parameter. A secondary feedback loop generates a secondary error signal that is proportional to the difference between the selected value of the first parameter and a measured value of a second flight parameter, which is the other of the airspeed and inertial velocity. The primary and secondary error signals are summed to produce a velocity error signal, and the velocity error signal and an integrated value of the primary error signal are summed to produce an actuator command signal. The actuator command signal is then used for operating aircraft devices to control the first parameter to minimize the primary error signal.”

The patent was filed on Sept. 12, 2005, under Application No. 12/064,476.

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