130 Figure 16-22.  Finding true heading by the wind correction angle.  Figure 16-23.  Finding true heading by direct measurement.  Briefly summarized, the steps in obtaining flight information  are as follows:  • TC—direction of the line connecting two desired  points, drawn on the chart and measured clockwise  in degrees from TN on the mid-meridian  • WCA—determined from the wind triangle. (Added  to TC if the wind is from the right; subtracted if wind  is from the left)  • TH—direction measured in degrees clockwise from  TN, in which the nose of the plane should point to  remain on the desired course  • Variation—obtained from the isogonic line on the  chart (added to TH if west; subtracted if east)  • MH—an intermediate step in the conversion (obtained  by applying variation to TH)  • Deviation—obtained from the deviation card on the  aircraft (added to or subtracted from MH, as indicated)  • Compass heading—reading on the compass (found by  applying deviation to MH) that is followed to remain  on the desired course  16-16  90 60 50  40 30 20 10 120 110 100  90  80  70  60  50  40  30 20 10  170 160 150  140  130  120  110  100  TH 076° AS 120  TC 090° GS 88  P  W  E  N  S  80  70 7  6  °  90 80 70 150 140 130 120 110 100  90 80 70  60  50  40  30  20 $^{10}$ 170  160  150  140  130  120 110 100  TH 076° AS 120  TC 090° GS 88  P  W  E  N  S  10  20  1  4  °  WCA =14° L 