The Head-up Guidance System is designed with features and capabilities that maximize operational features and capabilities that maximize operational benefits while enhancing flight safety.

In visual and low-visibility weather conditions, the HGS significantly improves flight safety. The HGS provides the pilot greater situational awareness whether flying manually or using airplane automation.

Unusual Attitude

If the HGS detects that the aircraft is in an unusual attitude - where the roll or pitch exceeds a preset limit - the symbology automatically changes to display an attitude ball graphic. This immediately alerts the pilot to the dangerous situation, and helps the pilot quickly return to a normal attitude.

Updates

The HGS computer is field loadable - which allows the computer to be updated with the latest software while remaining on the aircraft. The HGS computer software is easily updated using the central data loading capability of the aircraft (if available), or it can be reprogrammed via the computer front panel connector using a special cable and laptop computer. The advantages of on-aircraft data loading include eliminating the risk of connector problems, and the need to retest the connection to other systems on the aircraft. This simplification of the software update process significantly reduces the cost of adding new features to the HGS.

Tailstrike

On certain aircraft, there is a greater chance of striking the tail during a takeoff or approach. To help the pilot avoid an expensive tailstrike, the HGS has special symbology that warns the pilot when they are approaching a situation that would lead to a strike.

During takeoff, the HGS displays a bar showing the pitch angle that will cause a tailstrike. The pilot can avoid a tailstrike by keeping the boresight symbol below the bar.

During an approach, the HGS calculates whether the current energy state and attitude of the aircraft will cause the tail of the aircraft to strike the runway at touchdown. The HGS will alert the pilot by displaying a "TAILSTRIKE" warning message.

TCAS

To help the pilot during a TCAS alert, the HGS displays special symbology that helps the pilot comply with the TCAS Resolution Advisory.

The HGS displays a fly-to box based on information received from the TCAS, and the pilot maneuvers the aircraft so the flight path symbol is within the TCAS "box." The fly-to box is removed when the threat has passed.