Post by LOU on Oct 10th, 2011 at 5:12pm
This is the HSI and as Markoz said it is basically a compass. The horizon instrument above the HSI is called the ADI (Attitude Direction Indicator).
As you can see in the upper left part of the HSI the VOR - Omni Bearing Selector (OBS) or ILS course is in a three digit format as is the DME mileage readout in the upper right side (blank in this photo). The heading select is the white bug at the bottom of the picture on the N or north. The knob on the lower right of the instrument is what controls the heading bug, while the knob on the lower left controls the course input.
I hope that answers your question...if not try again! :)
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