Relative bearing indicator

The Relative bearing indicator is a kind of display of a radio compass (ADF ) in aviation, in which the relative direction (mainly non-directional radio beacon / NDB ) appears to beacon.

That it can be read off the angle at which the airplane's longitudinal axis is located to the station. In a display of 90 ° the station is exactly right, and in a display of exactly 270 ° left of the plane:

The RBI is the classic ADF indicator. The 360 ° scale is not adjustable at the RBI, the zero degree mark is at the top in the direction of the airplane's longitudinal axis. The needle of the RBI shows on the radio beacon ( NDB ). At the scale of the angle between the aircraft longitudinal axis and the direction to the NDB is read. This angle is the Seitenpeilung (English relative bearing).

This read Relative Bearing the pilot knows his direction to the NDB, based on its aircraft longitudinal axis. To get to the station, so to get a QDM for NDB, added to the flown Heading ( MH, Magnetic Heading) and relative bearing ( RB) according to the following formula:

MH RB = MB ( = QDM )

More modern devices are equipped with a manually rotatable and thus adjustable on the heading or automatically controlled by a gyro compass rose. This eliminates the conversion, and the QDM ( magnetic heading to the transmitter ) can be read directly