Q-routes are a specific type of RNAV route used in aviation. These routes do not rely on ground-based navigational aids. They are applicable at altitudes between 18,000 feet and FL450. You can find them on En Route High Altitude charts published by the U.S. Federal Aviation Administration (FAA). Generally, these routes require performance capabilities that are met by GPS, GPS/WAAS, or DME/DME/IRU RNAV systems. This is in line with the criteria outlined in Advisory Circular 90-100A, which focuses on U.S. Terminal and En Route Area Navigation (RNAV) Operations.
