Now, fixed-wing airliners dominate air travel, but they are a difficult technology to decarbonize. As the world looks to reduce emissions and fossil fuel consumption, aircraft are getting a second look, specifically hybrid aircraft.
US Marine Corps Captains Benjamin Cohen and John Schmaltz Jr. initially stumbled upon hybrid aircraft due to a different aspect of the climate crisis: wildfires. Around the time they began attending the Naval Postgraduate School (NPS) in mid-2020, the August Complex fire began to burn in Northern California. They wondered if there were better ways to help put out the flames, and this led them to one of the many uses for hybrid aircraft. His thesis, published in March 2022, ended up being a guide to help the DOD integrate a high-capacity mobility platform, through the example of a hybrid aircraft, into its fleet by partnering with the commercial sector, where it is being produced. hybrid aircraft innovation.
“We realized that there is much more we can and should do with this, so our thesis includes not only an analysis of aircraft performance and how the potential acquisition of these aircraft by the DOD would affect the cost of development and operating costs over time, but also when is the right time for DOD to join the process,” explains Cohen.
The students, with the help of their advisers, Drs. Nick Dew and Eva Regnier of the NPS Department of Defense Administration sought to modernize DOD’s approach to working with the commercial sector, from just purchasing prototypes to developing a long-term relationship with innovative companies. They specified in their thesis that they want the atlas to be a living document that “must be edited, adjusted and improved as technology advances”.
Cohen and Schmaltz presented the emission reduction aspect of hybrid aircraft technology as the second presentation in the Net Zero Briefings series presented by the NPS Climate and Security Network.
Hybrid airships are part of the “lighter-than-air” aviation family, which are powered by helium (not flammable hydrogen like the Hindenburg). Hybrid airships get their name because they combine conventional airship design with aerodynamic attributes, boost. Without it, the ship slowly sinks toward Earth because the payload makes the aircraft slightly heavier than air, so it doesn’t float like a balloon. Because power consumption is only needed to propel forward and not to lift, hybrid aircraft produce 75% fewer carbon dioxide emissions compared to similar conventional aircraft such as the C-5 Galaxy, and companies from aircraft are working to reduce emissions by 90%. They’re not as fast as competing planes, but they’re faster than most ocean-going vessels, creating new options for green ways to move cargo that’s needed in 48 hours, not five weeks.
Another important feature of a hybrid aircraft is that it can land on any reasonably flat surface, without the need for formal landing pads or runways. They are also quieter than comparable aircraft and still carry heavy payloads. This could allow for stealth and remote equipment deliveries. Landing anywhere and carrying heavy payloads, complete with precision gear and firefighting suppressors, is what made hybrid aircraft attractive for fighting wildfires.
Schmaltz, an amphibious assault vehicle officer, saw the potential for aircraft to improve the supply lines needed to keep the aging amphibious assault vehicle functional.
“We don’t necessarily know where we’re going, so we don’t have established supply lines to service old, expensive vehicles,” explains Schmaltz. “I saw value in the aircraft as a way of getting the things we needed to where they needed to go in a reasonable amount of time instead of waiting two or three months to get to certain places to ship or receive parts.”
While there have been exploratory programs in the past, hybrid aircraft are not used for military operations anywhere in the world at the moment, probably because they are slower and the technology was only fully developed in the last decade. The only lighter-than-air vehicles used by the DOD are aerostats, which are smaller low-level airborne ground surveillance systems used as radar platforms.
Hybrid aircraft innovation is taking off in the commercial space. Recognizing this, Schmaltz and Cohen worked with defense contractor Lockheed Martin and the British company Hybrid Air Vehicles (HAV), the latter of which built and flew a full-scale prototype hybrid aircraft, leading to a Cooperative Research and Development Agreement. (CRADA) with NPS. .
“It was an ideal opportunity to work with the USMC and NPS to test the Airlander, modeling multiple scenarios to demonstrate how the aircraft could support missions in the Indo-Pacific theater of command,” says Neil Gee, HAV Senior Project Manager. .
As part of CRADA, HAV and NPS students created goals that they would work on separately and ones that they would tackle together. One project they worked on modeled multiple scenarios to demonstrate if and how aircraft could support stability in the Indo-Pacific theater of command. They found that the hybrid aircraft could decrease travel time for infantry and equipment and reduce associated emissions in the process. Beyond improving supply chain response capabilities, the group also recognized that hybrid aircraft could be used to deliver humanitarian aid, disaster relief and remote research. HAV gained access to more meteorological data to expand their databases and also connected with faculty research associate Christian Fitzpatrick and the NPS Institute for Modeling, Virtual Environments and Simulation (MOVES), with whom they are still working today.
Since NPS prioritizes bridging academics with operational applications, both parties learned a great deal from each other in the process. Students gained a better understanding of the business process of producing a hybrid airship from prototype to production. And Schmaltz and Cohen’s research sharpened HAV’s focus on the digital technology side, such as producing a digital twin, which is a virtual representation of an object or system that spans its life cycle.
HAV brought the University of Sheffield’s Advanced Manufacturing Research Center (AMRC) into the project to help improve its understanding of digital engineering, augmented reality for maintenance and operation support, and the generation of 3D virtual reality environments to improve production efficiency. NPS students and HAV staff learned that there were many more industrial uses for digital twins than they initially thought. The relationship between AMRC and NPS will likely continue beyond this thesis project.
Forming all of these associations was good preparation for Cohen for his current assignment. After graduation, Cohen moved to Southern California to lead the NavalX SoCal Tech Bridge, which works to build partnerships between the shipbuilding and commercial sectors in and around San Diego. HAV plans to continue investigative work with Cohen through his new position. Schmaltz now works as a program analyst for the Deputy Commander for Programs and Resources, a role for which he found he is well suited due to his research efforts in hybrid aircraft.