DAC GDC31 GPSS Roll Steering Adaptor

The GDC31 Roll Steering Converter is designed to receive RS232 or RS422 serial data or ARINC 429 Label 121 from a GPS Navigation System to produce an analog Roll Sum Steering (RSS) signal.

 

The GDC31 output signal connects to the heading error input of the aircraft’s existing autopilot.  The GDC31 mimics the heading error signal of the aircraft’s installed HSI or DG.  The GDC31 does not reduce or otherwise alter any existing safety features of the autopilot, such as bank limiting, rate limiting and protection from a hard over.  The GDC31 provides lateral (roll) data only (no pitch data is supplied by the GDC31).

 

The pilot simply selects between heading mode and GPS mode by using the switch / annunciator.  In heading mode, the autopilot operates as always, tracking the heading bug of the HSI or DG.  In GPS mode, the GDC31 RSS signal drives the autopilot’s heading channel.  The GDC31 calculates the correct course intercept angle from the data supplied by the GPS, smoothly guiding the aircraft onto the course.  The GDC31 then holds the aircraft on the selected course.  If the GPS is programmed with Flight Plan data, the GDC31 will calculate the new intercept angle at each waypoint change, intercepting and holding the new course without pilot intervention.

 

The GDC31 is designed to operate with both rate based and position based autopilots.