What instrument provides VOR, ILS, DME, and heading information and is a primary attitude instrument?

• A. HSI
• B. HDI
• C. RMI
• D. EFIS

Answer: (A)

The instrument is the Horizontal Situation Indicator. It combines your heading with navigational bearings in one horizon-style display. The rotating compass card shows the direction you’re actually pointing (your heading), while a fixed airplane symbol and a course-pointer indicate the active VOR or localizer course. You can also see how far you are from that course and, on many HSIs, view DME readouts to know your distance from the station. For an ILS approach, the instrument can present both the localizer deviation and, with DME if equipped, distance information, all in the same view.

This integration is what makes it the best choice here: you get heading information and the VOR/ILS bearing information, plus DME, on a single instrument that’s central to situational awareness during instrument flight. Other options provide some of these pieces—bearing to a nav aid or a deviation indicator—but not the same comprehensive, combined navigation-and-heading display in one instrument.