Hoos On Fire: A Conceptual Aircraft Design Report; A Layer of Hope or a Layer of Harm? The Socio-Ecological Impacts of Firefighting Chemicals

As wildfires continue to ravage many parts of the world, new firefighting technologies are being invented and deployed to combat these natural disasters with an increasing demand. Firefighting aircraft, a primary contributor to large fire containment, are typically repurposed airframes, so the technology is outdated. The technical report solves this issue by designing a firefighting aircraft with state-of-the-art aviation and firefighting technologies. Another realm of firefighting technology that is often valued for its effective application are firefighting chemicals; however, these chemicals can cause harmful unintended consequences that affect various social groups. The STS research answers to what extent three common firefighting chemicals impact an eco-social network. The STS research directly influences the payload deployment design of the fire retardant in the technical research, so the two topics are tightly coupled.
With the use of state-of-art technologies, the technical report presents a complete conceptual design of a firefighting aircraft, capable of carrying over 8,000 gallons of fire retardant, yet maintaining a strong sense of maneuverability. The report breaks down the mission profile which governed the performance parameters of the final design, which is detailed afterward. Once the large-scale aircraft configuration was chosen, the design of the aircraft’s primary features involves trade studies, simulation analysis, and sizing iterations. However, the payload underwent a more creative route, as the payload design was unique to the firefighting application. Finally, once each part of the airplane was specified, the report identifies performance analysis and recommended next steps to continue to a preliminary design model.
The team, Hoos on Fire, designed the HoF-22 Material Girl, a standard-configuration firefighting aircraft with an effective length of 130 feet, wingspan of 195 feet, a take-off gross weight (TOGW) of 236,389 pounds, and a per-unit cost of $290 million. The aircraft’s structures are carefully designed to meet the mission performance requirements, and non-structural systems were selected based on off-the-shelf purchasing options and the thrust and landing load requirements, respectively. The payload design consists of multiple “cells” loaded onto a rail which lock cells in position, mirrored around the center of gravity.
The STS research explores the eco-social impacts of various firefighting chemicals. To answer this, a case study report individually assesses the impacts of three common firefighting chemicals: Phos-Chek, per- and polyfluoroakyl substances (PFAS), and polybrominated diphenyl ethers (PBDEs). For each chemical, the ecological and social impacts were assessed using article-style reporting, academic ethics research, and US federal safety documents. From these findings, a proper assessment on the continued use of this chemical was derived.
Phos-Chek exhibited the safest features, both to human and ecological groups; however, its unsolicited presence in neighborhoods can be off-putting and cause paranoia of its health effects, so spreading more information about its safety to the surrounding public of a wildfire is advised. Both PFAS and PBDEs were well-known dangerous chemicals, causing a range of health problems including high cancer rates upon exposure and being a “developmental neurotoxicant”. However, their environmental impacts were just as severe, with much less literature pronouncing these impacts. As a solution to these two chemicals, further research into their replacement is necessary to preserve the lives of firefighters and all exposed persons.
In conclusion, the results of both the technical and STS papers bring to light the need for increased research and interest in combatting the seen and unseen hazards of firefighting. With the development of a firefighting aircraft, more lives can be directly saved from wildfires, while improving the eco-social drawbacks of some firefighting chemicals can battle the unintended consequences caused by firefighting.

School of Engineering and Applied Science
Bachelor of Science in Aerospace Engineering
Technical Advisor: Jesse Quinlan
STS Advisor: Catherine Baritaud
Technical Team Members: Jaylon Williams, Jemma Johnson, Lama Khraibani, Logan Honts, Nicholas Martin, Quang Lam, Yicong Fu