Abstract: A drive system for an aircraft such as a tiltrotor aircraft. The drive system includes first and second gearbox assemblies in mechanical communication with each other. A first lubrication system is associated with the first gearbox assembly and includes a bifurcated tank configured to contain a lubricant in an operating chamber including a lower sump and in an emergency chamber including an upper sump. A second lubrication system is associated with the second gearbox assembly. An emergency pump is in fluid communication with the emergency chamber. The emergency pump is configured to supply the lubricant to the first gearbox assembly from the emergency chamber responsive to a failure in the first lubrication system. In addition, the emergency pump is configured to supply the lubricant to the second gearbox assembly and to the operating chamber from the emergency chamber responsive to a failure in the second lubrication system.

Abstract: A propulsion assembly for a rotorcraft includes a raceway having a tapered inner surface and a mast configured to receive the raceway at a raceway receiving station. The mast has a tapered outer surface at the raceway receiving station. The propulsion assembly includes a mast bearing assembly having a plurality of bearings facing the mast to engage the raceway. The tapered inner surface of the raceway is friction welded to the tapered outer surface of the mast at the raceway receiving station to form a tapered friction weld line.

Abstract: A propulsion assembly for a rotorcraft includes a raceway having a tapered inner surface and a mast configured to receive the raceway at a raceway receiving station. The mast has a tapered outer surface at the raceway receiving station. The propulsion assembly includes a mast bearing assembly having a plurality of bearings facing the mast to engage the raceway. The tapered inner surface of the raceway is friction welded to the tapered outer surface of the mast at the raceway receiving station to form a tapered friction weld line.

Abstract: A pump assembly, comprising a pump and housing having an inlet passage and an outlet passage. The pump includes inlet and outlet ports and opposing first and second drive inputs configured to be rotated together in a pumping direction to operate the pump. The pump can be installed in the housing in a first orientation, in which the first drive input is configured for being rotated by a drive source in a first external direction to operate the pump, and a second orientation, in which the second drive input is configured for being rotated by the drive source in a second external direction opposite of the first external direction to operate the pump. In both the first orientation and the second orientation, the inlet port is in fluid communication with the inlet passage and the outlet port is in fluid communication with the outlet passage.