Abstract:
Over the past few years, there has been a growing interest by military services to reduce the risks to aircraft and crew during extraction of wounded soldiers. As recently as this year, the U.S. Army Medical Research and Materiel Command (USAMRMC) is examining initiatives for a next generation trauma care capability centered on autonomous, unmanned, and robotic solutions. While the ultimate goal of trauma care autonomy is to sustain life, the need still exists to extract wounded soldiers via VTOL aircraft. While estimates vary, Air Mobility Command Aeromedical Evacuation (AE) forces support approximately 20,000 combined fixed and rotary wing airlift movements annually. During Vietnam, AE was responsible for transporting 108,000 wounded soldiers from a combat zone to medical facilities. Intra-facility transport accounted for an additional 280,000 troop transports. Last year in the United States, civilian Helicopter Air Ambulance Operations (HAAO) account for the transport of over 500,000 patients annually. HAAO experience, while non-combatant, offers significant experience in operational processes and airlift requirements when there is an emergency involving immediate threat to life, limb, or sight. As military services are challenged with providing soldier location and extraction in austere and ever-increasing hostile environments, there has been numerous air vehicle design configurations proposed and even flight tested to meet the requirements. However, the operational procedures considering air vehicle and patient extraction can be extremely challenging for piloted flight and medical crews. Promising design solutions are a result of recent developments in electric VTOL (eVTOL) technologies. Distributed Electric Propulsion (DEP) solutions allow designers flexibility in locating propulsors and eliminating fossil fuel systems. These advancements result in structural designs that are more conducive to patient ingress and egress. In addition to structural design flexibility, eVTOL designs offer other benefits versus Internal Combustion Engines (ICE) counterparts to include reduced acoustic and thermal signatures and greater agility and maneuverability while eliminating the required pilot and aircrew resting periods during up-tempo operations. Autonomous air vehicle design considerations for Air Mobility Aeromedical Evacuation are developed based on HAA and US Armed Forces airlift experience with avionics, flight procedures, and air crew operations.