DRVSM stands for which concept in domestic airspace operations?

• A. Direct User Access Terminal System
• B. Domestic Remote Vertical Separation Measure
• C. Domestic Reduced Vertical Separation Minimum
• D. Dynamic Range of Vertical Separation Measures

Answer: (C)

Domestic Reduced Vertical Separation Minimum is the practice of applying the reduced vertical separation standard within U.S. domestic airspace to allow 1,000-foot vertical separation between aircraft operating in the RVSM altitude band, typically between Flight Levels 290 and 410. This alignment with international RVSM standards increases airspace capacity and efficiency while preserving safety, ensured by requiring aircraft to have two independent altitude measurement sources and automatic altitude-keeping capability, along with reliable altitude-encoding transponders and approved procedures. The other terms referenced do not describe this concept: one refers to a terminal system unrelated to vertical separation, and the others are not recognized terms for this practice.