Conversion spindle with dual ducted tiltrotors

A duct assembly for a ducted-rotor aircraft, the duct assembly comprising:

• first and second ducts, each duct including a rotor that is disposed in an opening that extends through the duct, the rotor having a plurality of blades;
• and
• a spindle that is configured to support the first and second ducts,
• wherein the first and second ducts are coupled to the spindle.

A spindle for a ducted-rotor aircraft, the spindle comprising:

• a shaft that extends from a first end to an opposed second end;
• first and second fittings that are configured to be disposed onto, and secured to, the first and second ends of the shaft;
• and
• first and second bearings that are mounted on the shaft and that are configured to rotatably couple the spindle to a fuselage of the aircraft,
• wherein the first bearing is configured to react to radial loads and the second bearing is configured to react to both radial and axial loads.