PLT355: Horizontal Situation Indicator
What code PLT355 covers, why the FAA tests it, and how to study Horizontal Situation Indicator before your checkride.
Recall radio - HSI
What this means for your checkride
The horizontal situation indicator (HSI) combines the heading indicator and the CDI into one display. It presents VOR or localizer course information together with aircraft heading, giving a visual picture of the aircraft's position relative to the selected course.
The HSI reduces interpretation errors by merging heading and course guidance, so pilots must read course deviation and TO/FROM sense correctly.
Students sometimes forget that if the course arrow is set opposite the intended track, the CDI needle indications reverse.
Where to study it
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.