When cleared direct from one point to another, you must determine the heading to fly. One
method of determining this is to plot both points on a suitable chart and connect them with a
straight line. The heading to fly is the heading along this line. An alternate technique, which
eliminates cumbersome charts and line drawing, will require you to visualize the aircraft's present
position and the desired fix on the compass card of the RMI. This method may be used to
navigate directly to any fix within reception range of the NAVAID. The following concepts will
aid in developing this ability.
The TACAN station is always at the center of the compass card. The compass card is merely a
compass rose around the station.
The fix having the greater distance is always established on its radial at the outer edge of the
The remaining fix is established along its radial at a proportional distance from the center of the
When applying the above concepts, the compass card can be thought of as a chart. On this chart,
you have plotted your present position, the desired fix, and the TACAN station (at the center).
With an actual chart, you could draw a line between the two fixes to determine nowind heading.
Using the compass card you visualize this line between fixes.
The following example and the illustrations in Figures 633 and 634 demonstrate the procedures
for flying from one TACAN fix to another TACAN fix. The aircraft is on the 180º radial at 20 NM
and you want to navigate to the 90º radial at 10 NM.
Tune and identify the station.
Turn in the shortest direction to a heading between the head of the RMI needle and the
desired fix radial. If going to a smaller DME, favor the head of the needle. If going to
a larger DME, favor the desired radial.
The Instrument Approach Plate may be used as an aid to visualize
your position and the initial heading required to fly to the fix.
6-54 RADIO INSTRUMENT FLIGHT PROCEDURES