What is the starting width of the horizontal plane?

What is the starting width of the horizontal plane?

• A. 5000 ft
• B. 9000 ft
• C. 2000 ft
• D. 16000 ft

Answer: (B)

The starting width of the horizontal plane establishes the baseline lateral space around the runway used for safe maneuvering and obstacle clearance. Setting this width at 9,000 feet provides a practical balance: it accommodates typical turns and the footprint of common aircraft while keeping the protected area from becoming unwieldy. A width of 5,000 or 2,000 feet would be too narrow for safe operations, increasing the risk of conflicts with obstacles or airplanes, whereas 16,000 feet would be unnecessarily large without adding proportional safety benefits for standard field operations.

The starting width of the horizontal plane establishes the baseline lateral space around the runway used for safe maneuvering and obstacle clearance. Setting this width at 9,000 feet provides a practical balance: it accommodates typical turns and the footprint of common aircraft while keeping the protected area from becoming unwieldy. A width of 5,000 or 2,000 feet would be too narrow for safe operations, increasing the risk of conflicts with obstacles or airplanes, whereas 16,000 feet would be unnecessarily large without adding proportional safety benefits for standard field operations.