Flying an airplane or a helicopter in low visibility conditions due to weather and/or time of day is a task that puts a very high workload on the pilot. The high workload increases the chances for mistakes in case of an emergency. Synthetic Vision System (SVS) technology emerged from the need to see through the darkness and through the clouds, to bring back a VFR view of the world in IFR conditions.
A synthetic vision system overlays relevant terrain information on the symbology of a primary flight display. The most advanced SVS PFDs use HUD symbology in place of the conventional pitch based PFD symbology to give the pilot a view into the energy state of the aircraft compared to the terrain it is overflying. Furthermore the HUD symbology helps the pilot during non-precision and precision approaches to the airport or the landing pad, clearly indicating the aircraft path and energy state.
The terrain can be displayed in several different resolutions with the new state of the art being 3 arc sec. This resolution allows for an excellent definition in critical geographic areas like mountainous terrain.
The most advanced SVS blend the Terrain Awareness and Warning System (TAWS) indications with the terrain depiction to show the pilot how close he/she is. In this case the terrain is colored with the TAWS alerts to draw the attention of the pilot and provide look-ahead warnings.
Finally, very few SVS systems are tailored to the unique needs of the helicopter community. The improved resolution of the terrain coupled with the merging of the terrain with external sensor inputs improves the usefulness of SVS to helicopter pilots.
Our goal at Astronautics for the introduction of SVS in our family of display products is to build a better PFD that can increase the situational awareness of the pilot in the most critical high workload situations like night flying or low visibility approaches.