US Air Force joins race for supersonic passenger flight

A Georgia-based start-up has picked up a US$1.5 million contract from the USAF to work on a hypersonic aircraft.  The start-up, Hermeus, wants to develop hypersonic passenger planes. Their new partner, the USAF, reckons there’s potentially room for hypersonic planes in its VIP fleet.

The idea of future US Presidents scooting around the countryside in hypersonic planes might give some pause for thought. On the flipside, the sooner they arrive, the sooner they depart.

Hermeus describes itself as a venture-backed company. They have a long-term vision of transforming the global human transportation network with Mach 5 aircraft. They won this contract after successfully tested a Mach 5 combined-cycle engine prototype in February 2020. The start-up built and tested the engine in just nine months. That’s impressive, but a scroll through the Hermeus leadership team and board of advisors shows some serious aviation and aeronautical engineering muscle.

Hermeus picked up the contract through AFWERX, the USAF innovation incubator. AFWERX was set up in 2017 by the Secretary of the Air Force. Its website describes AFWERX as “a community of Air Force innovators who strive to connect Airmen to solutions across the force: whether that be funding, collaborating with industry, or simply receiving guidance on a project.”

The start-up will team up with the Air Force’s Presidential and Executive Airlift Directorate, who are based at Wright-Patterson Air Force Base in Ohio. Hermeus says the money is to fund a rapid assessment of modifications to Hermeus Mach 5 aircraft. The aircraft will support the Presidential and Executive Airlift fleet.

“Early integration of unique Air Force requirements for high-speed mobility and evaluation of interfaces between high-speed aircraft and existing communications, airport, and air traffic control infrastructure lays the groundwork for a seamless transition to service,” Hermeus said in a statement.

“Additionally, Hermeus will prepare test plans to reduce the technical risk associated with these modifications to support Air Force requirements.”

It’s the combined-cycle engine that appears to have caught the eye of the USAF. These types of engines work by combining standard jet turbines with the aero thermodynamic duct ramjet style engines.

Hermeus says their successful test earlier this year served as risk reduction for their turbine-based combined cycle engine architecture. The test also illustrated their ability to deliver on time and on budget.

The idea is for the aircraft to take off and land like a regular plane but hit hypersonic speeds midflight. Other than the engine, no real modifications are needed for the plane.

“Using our pre-cooler technology, we’ve taken an off-the-shelf gas turbine engine and operated it at flight speed conditions faster than the famed SR-71.  In addition, we’ve pushed the ramjet mode to Mach 4-5 conditions, demonstrating full-range hypersonic air-breathing propulsion capability,” said a Hermeus spokesperson.

“Leaps in capability are vital as we work to complicate the calculus of our adversaries.” That’s according to Brigadier General Ryan Britton, the program Executive Officer for Presidential and Executive Airlift at the USAF. 

“By leveraging commercial investment to drive new technologies into the Air Force, we are able to maximize our payback on Department of Defense investments.”

While there is a lot of work going on in the hypersonic and supersonic field, Boom Supersonic and Virgin Galactic are two contenders that spring to mind; most are incredibly capital intensive. Hermeus demonstrates that innovation need not always be cost-prohibitive, that from the smallest amounts of funding, big things can grow.

Simple Flying