BASIC INSTRUMENT PROCEDURES
Figure 1-2 Radial Indication
It is essential that the student be able to orient himself to the station with the
information provided by the BDHI. As every advanced student knows, TACAN
provides azimuth as 360 radials emanating from the station like spokes from a
hub in a wheel.
These radials are identified by their magnetic direction from the station, as
indicated by the position of the tail of the number two needle on the compass
card (Figure 1-2).
In essence, the BDHI presents a geographic depiction of aircraft location
relative to the selected TACAN station, as well as its heading (Figure 1-3). It
can be used as a simple plotting board. The station is represented by the center
of the BDHI while the aircraft position is on the tail of the number two needle.
The head of the needle indicates the heading to fly to the station while the
aircraft heading is indicated under the heading indexer. Distance from the
station is displayed in the DME readout window.
1-14 BASIC INSTRUMENT PROCEDURES