What relationship do the two runway-end numbers have?

What relationship do the two runway-end numbers have?

• A. They differ by 90 degrees.
• B. They differ by 60 degrees.
• C. They differ by 180 degrees; add or subtract 18 from the runway number.
• D. They are always the same.

Answer: (C)

Runway numbers come from the magnetic heading of the runway, shown in tens of degrees. The two ends point in opposite directions, which is a 180-degree difference. Since the number represents the heading divided by 10, the opposite end is found by adding or subtracting 18 (which equals 180/10). For example, a runway labeled 04 has the opposite end labeled 22 because 04 + 18 = 22, corresponding to roughly 040° and 220°.

Runway numbers come from the magnetic heading of the runway, shown in tens of degrees. The two ends point in opposite directions, which is a 180-degree difference. Since the number represents the heading divided by 10, the opposite end is found by adding or subtracting 18 (which equals 180/10). For example, a runway labeled 04 has the opposite end labeled 22 because 04 + 18 = 22, corresponding to roughly 040° and 220°.