If runway endpoints elevations are 410 ft and 300 ft, runway length 5000 ft, what is the slope percent?

• A. 1.1%
• B. 2.2%
• C. 5.0%
• D. 0.5%

Answer: (B)

Slope percent is a measure of how steep a surface is, calculated as the vertical change divided by the horizontal distance, times 100. Here, the vertical change from the lower end to the higher end is 410 ft minus 300 ft, which equals 110 ft. The horizontal distance along the runway is 5,000 ft. So the slope percentage is (110 / 5,000) × 100 = 2.2%. This directly matches the given elevations and length. The other percentages would require different vertical changes (for example, 1.1% would need a 55 ft rise, 5.0% would need a 250 ft rise, and 0.5% would need a 25 ft rise).