Integration Concept for a Hybrid-Electric Solid-Oxide Fuel Cell Power System into the X-57 "Maxwell"

Because of the growing Urban Air Mobility focus, this presentation provides an attractive alternative to the all-electric X-57 option

Development of a Multi-Phase Mission Planning Tool for NASA X-57 Maxwell

The physical design and operation of electric aircraft like NASA Maxwell X-57 are significantly different than conventionally fueled aircraft. Operational optimization will require close coupling of aerodynamics, propulsion, and power. To address the uncertainty of electric aircraft operation, a system level Mission Planning Tool is developed to simulate all aircraft trajectory phases: taxi, motor run-up, takeoff, climb, cruise, and descent. The Mission Planning Tool captures performance parameters at each point of the trajectory including battery state of charge, the temperatures of components in the electrical system, and propulsion system thrust. This work describes the modeling of each mission phase, and compares the results of simulating a user-specified trajectory, and using a collocated optimal control approach to determine an optimal trajectory. The results show that optimization of the mission show a significant increase in the final battery state of charge over the user- specified simulation strategy. These results will inform the operation of the NASA Maxwell X-57 test flights that will take place this year

Die Teilzeitfalle in der Invalidenversicherung

Je nach konkreter Konstellation kann Teilzeitarbeit den IV-Rentenanspruch in der ersten und zweiten Säule gefährden. Da Teilzeitarbeit überwiegend von Frauen geleistet wird, stellt dies eine indirekte Diskriminierung aufgrund des Geschlechts dar. Für die Invaliditätsbemessung sollte deshalb einzig massgebend sein, welches Einkommen die versicherte Person in einem hypothetischen Gesundheitsfall erzielen könnte

FUELEAP Model-Based System Safety Analysis

NASA researchers, in a partnership with Boeing, are investigating a fuel-cell powered variant of the X-57 Maxwell Mod-II electric propulsion aircraft, which is itself derived from a stock Tecnam P2006T. The Fostering Ultra-Efficient Low-Emitting Aviation Power (FUELEAP) project will replace the X-57 power subsystem with a hybrid Solid-Oxide Fuel Cell (SOFC) system to increase the potential range of the electric-propulsion aircraft while dramatically improving efficiency and emissions over stock internal-combustion engines. Our FUELEAP safety analysis faces two primary challenges. First, the Part 23 certificated Tecnam P2006T is undergoing significant modifications to host the hybrid electric-propulsion system, and the challenge is to assure that the safety inherent in the stock aircraft (and subsequently in X-57 Mod-II) is not compromised by changes in avionics, aircraft structural loading, weight and balance, or other considerations. Secondly, because the SOFC power system has little (if any) relevant in-service precedent, our challenge is to assure that we identify and mitigate all reasonably plausible hazards introduced by unique FUELEAP equipage. We are investigating and utilizing Model-Based Safety Analysis (MBSA) methods to help us address these FUELEAP safety challenges. We captured aircraft-level system hazard conditions using instances of a SysML hazard block via aircraft-level Functional Hazard Analysis (FHA). Then, using SysML models of the FUELEAP architecture, we related the hazard conditions to initiating system events and possible mitigations, such as design architecture modifications or operational constraints. We are continuing to define our approach to MBSA by developing a component-by-component inventory of local failure modes and tracing their possible contribution to hazard conditions. Finally, we are applying an argument-based approach to FUELEAP assurance. Through a FUELEAP safety case, we are providing an explicit argument for FUELEAP safety by associating assurance evidence with overarching safety claims through a structured argument