ALEXANDRIA, Va., June 9 -- United States Patent no. 12,286,893, issued on April 29, was assigned to RTX Corp. (Farmington, Conn.).

"Apparatus and method for partially bladed rotor test" was invented by Zhiqiang Wang (South Glastonbury, Conn.) and Nicholas J. Lawliss (West Hartford, Conn.).

According to the abstract* released by the U.S. Patent & Trademark Office: "A rotor module, including: a blade cluster of a plurality of blades secured to a rotor disk of the rotor module; and counter weights secured to the rotor disk, wherein the counter weights cause a center of gravity of the plurality of blades to be zeroed out with respect to an axis "O" of the rotor disk and wherein the counter weights cause a moment of inertia Jx about an X axis ...