Radio Magnetic Indicator

CHAPTER ONE

INSTRUMENT FLIGHT RULES WORKBOOK

Figure 1-22 Radio Magnetic Indicator (RMI)

A course is the intended direction of flight or path over the ground measured in degrees. If an

aircraft is on the 180 radial and is tracking (actual path across the ground) inbound to the

station, the course would be 360. If that same aircraft were tracking outbound from the station

on the 180 radial, the course would be 180. When outbound from a station, the course and

radial are the same, and when inbound to a station, the course is the reciprocal of the radial.

Radial and course information are displayed on the RMI and CDI in the T-34C.

112.

RADIO MAGNETIC INDICATOR

The RMI is a navigation instrument that displays aircraft heading and radial information. It

consists of a rotating compass card and two bearing pointers, one for the VOR and one for the

TACAN. The aircraft's magnetic heading is displayed on the compass card beneath the

heading index. The remaining marks around the compass card are called bench markers. Bench

markers divide the compass card into 45 segments and are referred to by their relation to the

heading index (Figure 1-22).

1-28 INTRODUCTION TO AIRBORNE NAVIGATION AND COMMUNICATIONS

EQUIPMENT AND PRINCIPLES OF OPERATION