US Patent 10443706 Gearbox lubrication system

According to one embodiment, a rotorcraft includes a body, a rotor blade, a drive system that can be operated to rotate the rotor blade, and an emergency valve control unit. The drive system contains a first gearbox assembly, a second gearbox assembly, a first lubrication system that can deliver lubricant to the first gearbox assembly, and a second lubrication system that can deliver lubricant to the second gearbox assembly. The drive system also contains an emergency valve that can be opened to deliver lubricant from the first lubrication system to the second gearbox assembly. The emergency valve control unit can instruct the emergency valve to open.