Design Improvements for the Zenith 601 HDS:
The VFR instrument panel has Bendix King GPS/Com KLX 135A, transponder,
two electric gyros (Attitude, DG), Digitrak autopilot by TruTrak,
and Garmin GPSMAP 195 mounted forward of center stick.
The two GPS units have proved to be important since either unit
has run at times into an unrecoverable software error, resulting in
grossly misleading navigation information. Since the units are from
different manufacturers, they have never run into a software error
simultaneously. Thus, such problems can be detected by cross checking.
Recovery is by turning the unit with the software error off and then
The Digitrak autopilot has proved to be most useful.
The operation of the autopilot requires some care, as we discovered
during early flights; see Points for Pilots: Performance of Digitrak Autopilot by TruTrak.