For wilderness areas and communities battling devastating wildfires, first responders need to move swiftly and have the most efficient tools at their disposal.
Aviation plays a critical role in wildfire suppression and containment, and through the work of scientists, engineers, test pilots, and programmers, aircraft are becoming safer and more efficient, sustainable, and accessible than ever before. But is it possible for engineers to also channel these innovations to better serve the needs of the general public?
After a yearlong effort to explore the use of urban air mobility and regional air mobility vehicles within a firefighting scenario, three Virginia Tech capstone design teams swept the top three spots at this year’s NASA Aeronautics University Design Challenge.
Virginia Tech has a long history of success in undergraduate design team competitions. At this particular NASA design challenge, Virginia Tech teams have brought home top honors 11 times over the past decade. Clinching the top three spots in one year is unprecedented.
Starting with a solid foundation
The annual design competition, sponsored by NASA’s Aeronautics Research Mission Directorate, gives student teams the opportunity to solve some of the biggest technical challenges facing the aviation community today. Multidisciplinary teams put their skills to work by designing and building solutions to real-world problems.
Professor Pradeep Raj said he incorporates the NASA Aeronautics University Design Challenge into the classroom, in part, because the missions and technical challenges are often system-centric as opposed to focusing on a single vehicle.
“I’ve found that this approach tends to expand the scope and broadens the design space for the students,” said Raj. “Designing an operational fleet really opens up the possibilities for different types of vehicles, varying sizes, propulsion systems, and it challenges the students to investigate the overall operational aspects more closely for the fleet to successfully complete their mission.”
The undergraduate curriculum within Virginia Tech’s Kevin T. Crofton Department of Aerospace and Ocean Engineering leads up to a yearlong capstone design experience in the senior year. Aerospace engineering design courses use the group design process to both better simulate the way design is done in the real world and promote the benefits of collaborative learning.
Raj and Professor of Practice Wm. Michael Butler jointly served as the faculty instructors and advisors for the air vehicle design track within the capstone design course for the 2021-22 academic year. They bring a wealth of knowledge and experience in aerodynamics, vehicle design, and technology systems integration to the classroom.
Prior to joining Virginia Tech in 2012, Raj served three decades at Lockheed Martin, with the last 12 years in the Advanced Development Programs division known as Skunk Works. Butler, a three-time Hokie, spent more than two decades in the industry in advanced development programs. He worked as an air vehicle configurator at General Dynamics, which later merged under the Lockheed Martin corporation. Butler joined the Department of Engineering Education at his alma mater in 2013 and joined the aerospace and ocean engineering department in 2021.
Of the eight air vehicle teams advised by Raj and Butler this past academic year, four focused their efforts on the NASA extending public benefit proposal. Three teams ultimately submitted their written proposals to NASA, and out of approximately a dozen university teams participating, all three Virginia Tech teams rose to the top of the pack.
Design requirements
Urban air mobility and regional air mobility vehicles are vehicles used outside of intra-city passenger transport, and may include small drones, electric aircraft, and automated air traffic management systems. These vehicles could facilitate large production runs of small airframes for moving cargo and people, but also have an underexplored potential to serve other public purposes. They are designed to have very short or vertical takeoff and landings, low community noise, high utilization rates, and rapid deployment — which makes them well-suited for emergency scenarios, such as wildfire suppression and containment.
For the NASA competition, student teams were requested to design a suite of vehicles that can collectively deliver 3,000 gallons of water to a fire location in a single pass. The vehicles needed to be able to gather water from local water sources, such as lakes, rivers, or oceans, which require vertical short takeoff and landing operations. Currently, helicopters are used to reach these small water sources, and, therefore, the vehicle needed to be able to access similarly small or tree-enclosed bodies of water.
Teams also needed to consider how the vehicles collect the water, whether it is by scooping during a pass over the water or by landing on the surface to pump water into a collection tank. Each vehicle must either be operated remotely or by a single pilot and must be able to takeoff, land, and refill at night and in low visibility operations. Teams also were tasked with minimizing noise during takeoff and landing, keeping costs comparable to current approaches, and taking into account fuel and battery capacity, flight speed, and the number of water trips to maximize the water delivered to the fire location within a 24- hour period.
According to Raj, a common thread among the three award-winning teams was that they each adopted a collaborative, team-oriented approach early into the process. “Each of these teams was extremely self-motivated and really listened to the feedback from their design reviews,” said Raj. “They incorporated the feedback and suggestions into their thought process, and each delivered a substantial and comprehensive proposal to the NASA panel.”
Recent graduate Colin Fischer served as team lead for H2AERO, the Virginia Tech team that took home first-place honors. He said that although most of the teams’ aircraft ended up looking similar, H2AERO set itself apart by quickly establishing water capacity as a core design function.
“The main objective of the RFP is to deliver as much water as possible to the fireline,” said Fischer. “H2AERO did a lot of trade studies at the start looking into variables such as tank size or maximum range to find our optimum configuration, and our initial commitment to focusing on this objective function really gave us a leg up.”
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