Hermeus gets FAA approval to test unmanned aircraft at supersonic speeds

Hermeus has secured approval from the Federal Aviation Administration (FAA) to fly its Quarterhorse Mk 2.2 unmanned aircraft beyond Mach 1 during a limited test campaign over New Mexico. The authorization allows the U.S. aerospace company to conduct up to six supersonic flights over White Sands Missile Range by August 20, 2027. The operations must take place during daylight hours at or above 24,000 feet within restricted areas R-5111 A-D and R-5107. The approval comes as Hermeus develops Ramjet-X, an expendable ramjet-powered vehicle designed to be released from a reusable Quarterhorse aircraft. Although the authorization applies specifically to the Mk 2.2 test aircraft, it supports the company’s wider effort to expand access to high-speed flight testing. FAA clears Mach 1-plus testing Hermeus petitioned the FAA on May 22, 2026, for permission to conduct developmental supersonic flights with the experimental Quarterhorse Mk 2.2. It later submitted several revisions, and the FAA received the final version on August 20. To meet its environmental obligations, the FAA adopted the U.S. Army’s categorical exclusion determination. That decision was based on the Army’s Record of Environmental Consideration for Quarterhorse operations at White Sands. The regulator determined that the proposed flights would not significantly affect the quality of the human environment. It also found that Hermeus’ request was within the intent of 14 CFR 91.818, the federal regulation governing civil supersonic flight testing. The permission is not open-ended. Hermeus can exceed Mach 1 only under the conditions and limitations specified in the special flight authorization. Reusable aircraft replaces expendable booster Ramjet engines require considerable forward speed before they can operate effectively. High-speed test vehicles have therefore traditionally relied on large, expensive boosters to reach the conditions needed for ramjet-powered flight. Hermeus plans to use Quarterhorse as a reusable launch platform instead. The aircraft will carry Ramjet-X to the required speed and altitude, then release it. Ramjet-X will then begin powered flight, while Quarterhorse returns for future missions. The approach is intended to remove the need for a purpose-built, expendable booster during every test. It could also make sustained high-Mach conditions more accessible for researchers and technology developers. Ramjet-X supports high-speed testing service Hermeus plans to use Ramjet-X to offer high-Mach Flight Test as a Service. Customers will be able to test sensors, communications systems, autonomous technologies, computing equipment, materials, propulsion systems, and other experimental payloads under representative conditions. “High-speed flight testing is extremely expensive, and you don’t get many shots at it,” said Zach Shore, CEO of Hermeus. “Ramjet-X gives us a way to put new systems into sustained high-Mach environments without building an expensive one-off test program every time. Bringing speed, sustained flight, and scalability all into one system lowers the barriers to gathering extremely valuable data from these conditions and accelerates programs for both us and our customers,” he added. Hermeus is testing the Ramjet-X engine at its High Enthalpy Air-Breathing Test facility in Jacksonville, Florida. are company is developing high-temperature structures at its El Segundo, California, headquarters, with integrated vehicle testing planned for 2027.Get the latest in engineering, tech, space & science - delivered daily to your inbox.Atharva is a full-time content writer with a post-graduate degree in media & amp; entertainment and a graduate degree in electronics & telecommunications. He has written in the sports and technology domains respectively. In his leisure time, Atharva loves learning about digital marketing and watching soccer matches. His main goal behind joining Interesting Engineering is to learn more about how the recent technological advancements are helping human beings on both societal and individual levels in their daily lives.