T-6A INSTRUMENT NAVIGATION
Monitor the station identifier to ensure continuous signal integrity.
5. Confirm the correct source for the bearing pointer and CDI. Navigation information is
reliable only when:
The warning indicator (red X) is not displayed.
The NAVAID identifier is received.
The aircraft is in within the usable range of the equipment.
Twist the proper course into the CDI.
7. Update Navigation. Ensure the present heading falls between the head of the bearing
pointer and the desired radial. Then use the "pencil-method" to further refine the aircraft track
toward the fix.
Establish the fix with the greater distance (20 NM) at the edge of the compass card on
its radial (180°).
Establish the remaining fix (090° radial/10 NM) along its radial at a proportionate
distance from the center of the card (halfway).
Draw an imaginary line with the aid of a pencil or finger (no other straight edge aid is
authorized in the cockpit) from the aircraft's present position through the next fix
(Figure 4-9). Move the "line" to the center of the card. Now read the no-wind
heading to the desired fix (approximately 030° in this case). Be aware, the taper of
the pencil point and thickness of the pencil will induce a slight heading error.
The time required to proceed to the new fix can be derived by
estimating the length of the "line" between the two fixes and using
the scale already determined as the distance to the outer edge of the
compass card (in this case about 25 miles). Divide the distance by
the GS in miles per minute to determine the time enroute and the
ETA to the new fix.
4-26 INSTRUMENT NAVIGATION