By Lionel M. Lavenue

Upgrading to an HSI has never been easy or cheap. The choices are few and the costs are high. Typical of HSI shopping is the dilemma I faced last year. I traded up from a Cessna T206H to a Piper Mirage. The 206 was superbly equipped with Garmin navigators and a Sandel SN3308 EHSI, now discontinued after sales of more than 4000 units.

The Mirage had a conventional Bendix/King KCS55A HSI. I flew the SN3308 for five years and found that it gave good service. Although I did have to replace some bulbs and return the unit once for a new power supply, I never suffered a black screen in…