If two departures originate from different secondary airports and have overlapping lateral airspace, what separation is required?

• A. Horizontal separation
• B. Vertical separation
• C. Non-Radar separation
• D. Radar separation

Answer: (B)

When lateral airspace overlaps, you can’t rely on keeping the two aircraft apart horizontally. The safe, reliable way to ensure separation is to place them at different altitudes, establishing vertical separation between them. By assigning distinct flight levels, you maintain a known vertical gap regardless of where each aircraft is laterally, which is essential when their paths could come close or cross. In this scenario, that vertical separation minimum (such as the standard 1,000 feet in RVSM airspace) is the mechanism that guarantees separation. Horizontal separation isn’t dependable here due to the overlapping airspace, and non-radar or radar usage would address surveillance conditions rather than this specific need for vertical discrimination.