In a DME arc navigation, after the first 90-degree turn, what adjustment should be made to the CDI?

• A. Center CDI, then twist 10
• B. Center CDI, twist 5
• C. Twist only
• D. Do nothing

Answer: (A)

Tracking a DME arc means your CDI must reflect the tangent direction of the circular path around the VOR, not the straight radial to the station. After you complete the first 90-degree turn onto the arc, resetting the CDI to center gives you a neutral reference for the new curved leg. Then applying a small course offset—about 10 degrees toward the inside of the arc—aligns the CDI with the arc’s tangent. This offset provides the proper deviation cue to stay on the circular track and helps you compensate for wind as you follow the arc.

If you only twist without centering, you’re still based on the previous reference and the CDI won’t accurately reflect your position on the arc. Centering without offset won’t align you with the arc’s tangent either, and doing nothing leaves you with the old reference, making it harder to maintain the curved path.