Operations within airspace designated as Reduced Vertical Separation Minimum airspace.
CFR · 2024-01-01 · US · Title 14
(a) Except as provided in paragraph (b) of this section, no person may operate a civil aircraft in airspace designated as Reduced Vertical Separation Minimum (RVSM) airspace unless: (1) The operator and the operator's aircraft comply with the minimum standards of appendix G of this part; and (2) The operator is authorized by the Administrator or the country of registry to conduct such operations. (b) The Administrator may authorize a deviation from the requirements of this section.
official document · source cfr-2024 · id 14:§ 91.180