Sandel Avionics last month introduced the SN3500 line of electronic HSI units, featuring compass, map, flight-plan display and RMI, along with traffic, terrain and weather displays. Developed as a replacement for the SN3308, the new product line includes the basic 3-ATI EHSI and supports nav functions, mode-S transponder traffic input and the WX-500 Stormscope. According to Sandel, there are three versions of the SN3500. They are the new SN3500T, which includes FAA-certified Class-C TAWS warnings, along with relative and topographical terrain mapping; the SN3500W, which offers nav functions and an interface to WSI datalink weather; and the SN3500TW, which provides all nav and safety functions. Scheduled for availability in the fourth quarter of this year, the basic Sandel SN3500 will carry a retail price of $10,990, according to the manufacturer.