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Claudia Sales

Publications and source records attributed to Claudia Sales.

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

X-57 Systems Engineering Lessons Learned

The X-57 Maxwell is an electric aircraft based on a 4-passenger, twin engine Tecnam P2006T General Aviation aircraft. The X-57 project originally envisioned a straightforward integration of commercial-off-the-shelf hardware components and software into a novel configuration to demonstrate the aerodynamic and performance benefits of Distributed Electric Propulsion (DEP). The project was initially started with a high-risk venture capitalist approach under NASA’s Convergent Aeronautics Solutions (CAS) project, which led to an initial philosophy of Project Management “light” (which was then interpreted as Systems Engineering (SE) “light”). As the project matured, it was forced to transition to one with increasing SE-rigor as the project scope changed, hardware and software deficiencies were found, and the team realized the magnitude of the technical and integration challenges. In hindsight, these technical challenges came in part from an overly optimistic technology readiness assessment (TRA) at the beginning of the project, which resulted in the project assuming that little to no subsystem development would be required. The project’s approach to systems engineering evolved throughout three separate informal phases of the project as it underwent two key transitions as a result of the team wrestling with the technical challenges and resultant changing project scope. This paper discusses the assumptions, approaches, and challenges encountered from a Systems Engineering standpoint in each of the three informal phases of the X-57 project. This paper also provides recommendations on how future projects can apply Systems Engineering best practices upfront along with a realistic TRA to aid projects that find themselves with similar challenges.

Systems Engineering↗
NASA NTRSDate not supplied

Flight-Test Approach for X-57 Mod II Configuration

The primary objective of the X-57 Mod II test flights is to perform a functional checkout of the research traction battery power and motor systems, perform an airworthiness assessment of the modified vehicle, and to collect baseline performance, stability, and acoustic data for comparisons with later modifications of the X-57 airplane. This paper describes the planned flight operations of the Mod II airplane, the unique considerations and decisions made in operating an electric aircraft, and the development and planning of the research test points necessary to achieve the Mod II flight objectives. Due to the constrained flight time, which resulted from limited capacity of the battery system, careful scripting of flights was required to maximize test time and execute test points efficiently.

James Reynolds↗
NASA NTRSDate not supplied

Distributed Thrust Takeoff for the NASA X-57 Mod IV Flight Demonstrator

The Mod IV configuration of the X-57 flight demonstrator concept featured two forms of distributed electric propulsion—one cruise propulsor at each wingtip for primary propulsion that enabled favorable interaction with the wingtip vortex, and six high-lift propulsors distributed along the leading edge of each wing to enhance low-speed flight characteristics. The power system that fed these propulsors was arranged in two independent power buses. This unique arrangement did not lend itself to traditional “one engine inoperative” methods for determining performance after a critical failure in the propulsion system. Several potential failure scenarios were identified as potential “critical loss of thrust” events, and experiments that included pilot-in-the-loop simulation with the project test pilots were conducted to determine if these events would result in adequate handling and performance. Prior research showed that a total failure of one of the cruise motors during takeoff or initial climb could result in unacceptable performance for a traditional full-power takeoff. A new technique dubbed Distributed Thrust Takeoff (DiTTo) was developed to reduce the impact of the thrust asymmetry and total loss of thrust that could occur in any of the critical loss of thrust scenarios. The results showed that adequate performance and handling qualities could be achieved in each of the critical failure scenarios when using the DiTTo technique.

Distributed Propulsion, Electric Propulsion, Criti↗
NASA NTRSDate not supplied

Distributed Thrust Takeoff for the NASA X-57 Mod IV Flight Demonstrator

The Mod IV configuration of the X-57 flight demonstrator concept featured two forms of distributed electric propulsion—one cruise propulsor at each wingtip for primary propulsion that enabled favorable interaction with the wingtip vortex, and six high-lift propulsors distributed along the leading edge of each wing to enhance low-speed flight characteristics. The power system that fed these propulsors was arranged in two independent power buses. This unique arrangement did not lend itself to traditional “one engine inoperative” methods for determining performance after a critical failure in the propulsion system. Several potential failure scenarios were identified as potential “critical loss of thrust” events, and experiments that included pilot-in-the-loop simulation with the project test pilots were conducted to determine if these events would result in adequate handling and performance. Prior research showed that a total failure of one of the cruise motors during takeoff or initial climb could result in unacceptable performance for a traditional full-power takeoff. A new technique dubbed Distributed Thrust Takeoff (DiTTo) was developed to reduce the impact of the thrust asymmetry and total loss of thrust that could occur in any of the critical loss of thrust scenarios. The results showed that adequate performance and handling qualities could be achieved in each of the critical failure scenarios when using the DiTTo technique.

Distributed Propulsion↗