If true course is 090 degrees and the wind correction angle (WCA) is 20 degrees, what is the true heading?

To determine the true heading when given the true course and the wind correction angle, it's important to understand how wind affects the aircraft's path. The true course of 090 degrees indicates the intended direction of flight, which is eastward. The wind correction angle (WCA) is the degree to which wind alters that course, either by pushing the aircraft off course or providing a beneficial adjustment.

In this case, with a WCA of 20 degrees, if the wind is pushing from the left (a left crosswind), the aircraft will need to adjust its heading to compensate. Therefore, you subtract the WCA from the true course.

Calculating this gives:

True Heading = True Course - WCA

True Heading = 090 degrees - 20 degrees = 070 degrees

Thus, the correct heading the pilot should maintain in order to offset the effects of the wind and achieve the true course is 070 degrees. This adjustment ensures that the aircraft remains on the intended path despite external environmental factors such as wind.