Hermeus Plans Engine Tests On Mach 5 Hypersonic Concept Aircraft


Hypersonic aircraft hopeful Hermeus reports it expects to complete several engine test runs by October for its “Quarterhorse” Mach 5 scaled testing concept aircraft. The turbine-based combined cycle engine, based on the venerable GE J85 jet, is part of the program jointly funded by the U.S. Air Force in a $60 million 50/50 public-private investment agreement. From the USAF perspective, the deal focuses on capturing flight testing data with an eye toward future procurement decisions.

According to its website, “Hermeus was founded in 2018 with the mission to radically accelerate air travel. Using lessons learned from our time at NewSpace companies, we’re developing Mach 5 aircraft to connect people faster and bring much needed innovation to commercial flight.”

Quarterhorse is meant to lead to Darkhorse, a fourth-generation fighter-size aircraft designed for high-speed, long-duration trials. Part of the development program includes evaluating full-scale engines as well as environmental and thermal control components. The ultimate goal is developing the Mach 5, 20-seat Halcyon passenger version.

Mark Phelps
Mark Phelps is a senior editor at AVweb. He is an instrument rated private pilot and former owner of a Grumman American AA1B and a V-tail Bonanza.

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  1. So is it battery or hydrogen powered? Does it run on bio-diesel? Sounds that what passengers really want are airlines that don’t cancel flights and the end of a TSA that gets in the way of pleasurable, affordable air travel as we had in the 60s through the 80s. Mach 5 passenger travel? Who really believes that this is anything other than a weapon delivery system?

  2. Don’t believe I be a-getting on a Mach 5 airliner regardless of how small. At that velocity a problem could become catastrophic rather quickly or are the passengers going to wear full pressure suits, helmets, and parachutes?

  3. Progress is a series of crawls, occasional leaps, and failures, some catastrophic. If this thing achieves a safety record on par with current commercial travel, I’d buy a ticket tomorrow. Since landings and takeoffs are the significant safety threats, if this idea can somehow slow down to land at current jet propelled aircraft speeds, it’ll possibly be safe. Landing at speeds of an F-104 Starfighter? Uh…probably not. As for high speed disasters, well, that possibility seems like a quick way of dying. Certainly beats agonizing in a nursing home somewhere!

  4. I’m happy to see research like this being undertaken to expand our knowledge of high speed flight. It’s something that may benefit the military. However, I question whether it will end up producing a viable civilian transport aircraft. That is mainly because of the economics of operating such a craft. The Concord was a good aircraft, but the huge cost of operation basically made it uneconomical as an airliner due to the small number of seats available for paying customers. I suspect the same would apply here.