ALEXANDRIA, Va., Sept. 8 -- United States Patent no. 12,728,984, issued on Sept. 8, was assigned to VERTICAL AEROSPACE GROUP Ltd. (Bristol, Great Britain).

"Rotor assembly" was invented by Mark Cornborough (London), William Soukal-Walsh (London), Sean Briscall (London), James East (London) and Tiago Vasconcelos (London).

According to the abstract* released by the U.S. Patent & Trademark Office: "A rotor assembly includes a first rotor, a second rotor and a damper system. The first and second rotors are arranged to be rotated about a common axis for thrust generation by a drive system. The first rotor is rotatable about the common axis relative to the second rotor between a stowed configuration of the rotor assembly in which a rotor blade ...