On the heels of Dynon Avionics releasing two new EFISes, the company has released Operating System 5.1, which adds several new features to both the flight displays but to its own autopilot as well. One of the key features in the 5.1 update is something called GPS Assist. Since the beginning, Dynon EFISes have used airspeed to aid the attitude display. The company says that airspeed aiding is the most accurate and effective way to enable the use of low-cost sensors and further allows the system to be booted up in flight to very quickly provide accurate attitude indications. This system has proven itself over time. However, it requires a valid airspeed signal to operate properly, forming a single point of failure. So the purpose of GPS Assist is to provide a secondary airspeed source (GPS-derived groundspeed, in this case) that can take over in the unlikely event of pitot-tube blockage or some other form of pitot/static system malady. In addition to the GPS Assist function, the 5.1 software adds new features to the company’s autopilot system. This update adds true preselects. The pilot can preset heading/track and altitude before engaging the autopilot, which will then turn to and climb or descend to the bugged settings. Nav tracking of VOR and localizer signals has also been added, along with GPS Steering (GPSS) when the autopilot is used in conjunction with the HS34 expansion module and a GPS that outputs GPSS commands. At this time, the new nav tracking is in the lateral mode only; the autopilot does not follow the glideslope portion of an ILS nor does it follow GPS Vertical Steering commands. These functions are likely to be part of a future software upgrade.The new software is free to owners of the EFIS-D10A, EFIS-D100 and FlightDEK-D180. For more information, visit Dynon’s web site.