NAVAIR helpfully provided journalists an engineering summary to describe the role played by the loose bolts that grounded the BellBoeing V-22 fleet earlier this week. It was my job this morning to summarize their summary for my news story. Here's what NAVAIR game me:
The swashplates transmit flight control inputs to each proprotor hub and blade assembly. Each swashplate has an inner rotating ring driven by the proprotor mast and connected to the lower end of three pitch change links. The non-rotating outer ring attaches to three fixed hydraulic swashplate actuators and is restrained from rotation by a four-bar anti drive assembly.After much wailing and gnashing of teeth, my liberal arts-trained mind came up with this:
The swashplate moves in response to flight control commands on a mast-mounted gimbal ring. The non-rotating ring accepts input from the three hydraulic swashplate actuators, as driven by the Flight Control Computers (FCCs) from outputs from the cyclic control stick, thrust control lever, and rudder pedals in the VTOL mode. These flight control inputs are transmitted to the proprotor hub assembly through the rotating ring of the swashplate assembly and the three pitch change links.
The missing bolts are supposed to hold in place a fixed swashplate that transmits flight control inputs governing the V-22's blade pitch during helicopter mode.