What is the highest obstacle in the Kamloops CYKA CFS zone?

• A. 4500 ft ASL
• B. 5100 ft ASL
• C. 6100 ft ASL
• D. 3000 ft ASL

Answer: (B)

The key idea is understanding how high the tallest obstacle is within a defined airspace so you can plan safe vertical separation. An obstacle’s height is given in feet above mean sea level (ASL), and the highest of all obstacles in the zone sets the upper bound you must be mindful of when routing or clearing approaches.

For Kamloops CYKA CFS zone, the published data indicate the tallest feature reaches 5100 ft ASL. That makes 5100 ft ASL the highest obstacle in that zone. The other figures (4500, 6100, 3000) do not represent taller obstacles within this zone, so they aren’t the highest. Remember, ASL refers to altitude above sea level, not height above the ground at a specific location. This distinction matters for calculating safe minimum altitudes and ensuring clearance over terrain and structures.