Between FL290 and FL410, the DRVSM vertical separation minimum is what?

• A. 2000 ft
• B. 500 ft
• C. 1000 ft
• D. 1500 ft

Answer: (C)

In DRVSM space, the vertical separation minimum between flight levels FL290 and FL410 is 1,000 feet. This is Domestic Reduced Vertical Separation Minimum, meaning that when both aircraft are properly equipped and meet the required altitude-keeping performance, controllers can safely place aircraft 1,000 feet apart in this band, increasing airspace capacity. Outside this band, or if either aircraft isn’t DRVSM-approved, the standard 2,000-foot separation applies. The capability relies on precise altitude measurement from two independent systems and robust vertical separation monitoring, so only aircraft that meet those equipment and maintenance standards operate within this reduced gap.