Aug 2026· Aerospace· Vol 13, pp. 732· 0 citations· 93 references
Abstract
The National Transport Safety Board found that Wheels-Up Landing was the second highest defining event for aircraft accidents from 2008 to 2022. The increasing push for sustainable propulsion and accompanying novel airframe architectures present new integration and safety challenges for aircraft design and development, among which is the structural integrity and crashworthiness of the aircraft under such extreme events. This paper examines the regulations and design requirements governing aircraft emergency Wheels-Up Landing scenarios, emphasising their implications for aircraft safety and structural integrity. It consolidates standards from aviation authorities, such as the FAA and EASA, which identify and define key requirements relating to occupant safety and fire prevention and protection during such events. The paper then considers the Wheels-Up Landing scenario and its design requirements within the context of future novel aircraft employing sustainable propulsion systems, from higher bypass turbofan to electric- and hydrogen-based technologies. The unique characteristics and challenges of these emerging propulsion technologies are described, highlighting how alternative structural configurations, weight distributions and powerplant architectures may influence the aircraft response under a Wheels-Up Landing event. Finally, an exploration of predictive modelling strategies and methods currently used in Wheels-Up Landing analysis was conducted. While reviewing the breadth of accurate, high-fidelity modelling methods targeting fuselage impact, it also highlighted the gap in both considering the increasingly relevant and frequent powerplant impact scenarios, and the provision of lightweight modelling approaches necessary to rapidly and adequately address the emergency Wheels-Up Landing response early in the aircraft design process.
This paper outlines observations from an FAA-sponsored research project that examined aviation fly-by-wire (FBW) accidents in helicopters, transport-category airplanes, and powered-lift aircraft. The goal was to identify risk areas that will help guide a focus for FAA certification testing. Part of this study specifically focused on current powered-lift tiltrotors, identifying six general categories of causal factors for accidents, which will be discussed in detail regarding how they influenced flight control designs. The results of this survey, along with extrapolation to current designs, will be discussed and will illustrate why manufacturers are moving toward state-based flight control designs. In a state-based flight control scheme, the pilot does not have direct control over aircraft attitudes and motor tilt angles. Instead, the pilot requests a speed and or flight path with inceptor input, and the commanded attitudes and motor tilts are scheduled by the flight control computer. Additionally, recent lessons learned from electric vertical takeoff and landing aircraft accidents will be discussed, along with a comparison of powered-lift causal factors to accidents in the helicopters and transport category FBW fixed-wing aircraft. From this analysis, broad observations will be offered about the trend of how accident-causal factors may evolve with greater maturity in aircraft design. This accident survey will be detailed further as part of an upcoming FAA research report titled “An Approach to FBW HQ Testing Linking Development Tools to Civil Cert Requirements.”
Martin Shubert, David Sizoo, Michael Jones· Journal of the American Heli...· 0 citations
Abstract. A systematic review of the most promising technologies and aircraft concepts for reaching climate-neutral aviation is presented, based on a technology scouting for classification and benchmarking of their environmental performance. In a first step, a heuristic approach is used to analyse existing technology roadmaps on reducing environmental impact. The main levers commonly identified are technology advancements, operational measures, sustainable aviation fuel and demand management. The aircraft technologies from the aviation roadmaps are classified in a technology taxonomy in the categories aerodynamics, structural, systems and propulsion technologies and the entry-into-service is visualised in technology roadmaps. In a second step, an overview and categorisation of recent developments in advanced and disruptive (regional, short/medium and long-range) aircraft concepts is compiled. Environmental performance improvements can reach up to 40-50% (kerosene fuel burn and CO2) and 70% (NOX) compared to older reference aircraft, with reductions dependent on reference aircraft age. Hydrogen combustion offers zero CO2 while hydrogen fuel cells offer zero CO2 and NOX emissions. Different architectures are used for various ranges: Blended wing body and tube and wing (long-range), tube and wing (regional), and box-wing, double-bubble, strut-braced wing and tube and wing (short/medium range). While it is not possible to attribute a single reduction potential to a single technology feature, the most promising fuels are kerosene (conventionally, or in combination with batteries or fuel cells), sustainable aviation fuel and hydrogen. From the propulsion concepts, innovative turbofans (e.g. ultra-high bypass ratio turbofans) and innovative engines (e.g. hybrid-electric fans) had large improvements. In the field of aerodynamics, most applied technologies are high aspect ratio wings, riblets and laminar flow control, furthermore most concepts applied composite materials. For some aircraft concepts the climate impact was measured using climate metrics like ATR100 or GWP100, revealing trade-offs between fuel burn and climate impact or NOX emissions.
Lukas Söffing· Materials Research Proceedin...· 0 citations
Against the backdrop of accelerating urbanization and diversifying social demands, aerospace technology has extensively permeated numerous fields such as logistics and transportation, emergency and disaster relief, environmental monitoring, and urban transportation. Its application scope is expanding from traditional reconnaissance and surveillance to complex scenarios like material transportation, manned operations, and precision maintenance. Within this trend, high-payload, vertical take-off and landing (VTOL), and high-safety aircraft have become key equipment for enhancing operational efficiency across multiple sectors. Among these, high-payload ducted fan aircraft, with their high safety, excellent low-speed performance, and outstanding VTOL capability, demonstrate unique advantages in tall building fire suppression, power lines and towers maintenance, and personal flight experiences. This paper first outlines the diversified application prospects of aerospace technology, then focuses on high-payload ducted fan aircraft. It discusses the technical requirements specific to such aircraft in the aforementioned key scenarios and analyzes the critical technical bottlenecks hindering their broader application, along with potential viable solutions.
Bin Lou, Zhuoyuan Li, Yuansong Zhang et al.· SAE technical paper series· 0 citations
Characterizing the highly complex aero-propulsive interaction in distributed electric propulsion (DEP) aircraft may require automated flight-testing procedures with dedicated maneuvers, which introduce specific safety challenges. This paper investigates an accident involving a distributed electric propulsion research demonstrator, named SwitchMaster, during an automated flight-test mission for aerodynamic model identification. The event occurred during a scheduled pitch excitation maneuver and resulted in a loss of control followed by ground impact. The investigation is based on flight logs, telemetry analysis, and structured accident investigation methods, including the ICAO ADREP taxonomy and the Swiss Cheese Model. The results show that the accident resulted from a combination of open-loop control surface fixation, insufficient real-time safety barriers, ineffective maneuver interruption, and delayed recovery authority. Variable wind speeds and asymmetric trim acquisition are considered possible contributing factors to the aircraft drift from equilibrium conditions. This paper concludes with safety recommendations, software improvements and lessons learnt to enhance the reliability of automated flight testing for DEP aircraft.
Giorgio Filippoli, B. M. Perri, Niko Terzaroli et al.· Safety· 0 citations
Aviation decarbonization is one of the greatest challenges in the pursuit of sustainable mobility. While incremental improvements in aerodynamics, structures, and propulsion have led to sensible efficiency gains over the last years, the transition toward zero emission aircraft configurations requested by international guidelines needs disruptive technologies. Liquid hydrogen propulsion systems coupled with fuel cells are one of the most promising solutions to be investigated, since they offer high energy density, clean exhaust, and compatibility with regional aircraft missions. This study presents a novel configuration for a regional aircraft propelled by liquid hydrogen and fuel cells, based on conceptual design. The proposed configuration is a high-wing aircraft with T-tail. Unlike kerosene, liquid hydrogen requires specialized tanks and insulation, which significantly influence aircraft geometry and weight distribution. To address these challenges, the proposed configuration adopts a fuselage integrated cryogenic tank system installed in the aircraft rear cone, to minimize aerodynamic penalties while ensuring safety and operational feasibility. The fuel cell system is distributed to optimize redundancy and thermal management, enabling efficient power delivery to electric propulsors. The study contributes to the growing body of literature on hydrogen aviation by providing a system level configuration tailored to regional aircraft, a segment particularly suited for early adoption of hydrogen technologies due to shorter ranges and frequent operations. The findings underline the technical feasibility of liquid hydrogen–fuel cell systems, offering insights for future certification frameworks, infrastructure development, and industrial implementation. In conclusion, this work presents a feasible configuration of a novel green regional aircraft powered by liquid hydrogen and fuel cells. The results provide a foundation for further experimental validation and pave the way for the next generation of environmentally responsible regional aircraft.
Diego Giuseppe Romano, M. Barbarino, G. Fasulo et al.· Engineering Modelling, Analy...· 0 citations
The ongoing transition toward sustainable aviation has accelerated research efforts focused on hybrid-electric and fully electric aircraft concepts. While significant advances have been achieved in electric propulsion technologies, the integration of energy storage systems within conventional aircraft platforms remains a major engineering challenge due to their impact on aerodynamic performance, mass distribution, stability characteristics, and structural loading conditions. The present work investigates the aerodynamic and flight dynamic characteristics of a modified general aviation aircraft intended as a demonstrator platform for future electric propulsion integration. A representative low-wing general aviation aircraft was selected as the baseline configuration and subsequently modified through the incorporation of a ventral energy-storage container designed to accommodate battery systems. Aerodynamic analyses were conducted using the USAF Digital DATCOM methodology under representative cruise conditions. Lift, drag, and pitching moment coefficients were evaluated over a broad angle-of-attack range, while static and dynamic stability derivatives were determined to assess longitudinal and lateral-directional stability characteristics. A nonlinear six-degree-of-freedom flight dynamics model was subsequently developed to investigate aircraft responses to control surface and propulsion commands. Numerical simulations involving aileron, elevator, rudder, and differential propulsion inputs were performed in order to evaluate controllability, stability margins, and dynamic coupling effects. The obtained results demonstrate that the modified configuration preserves satisfactory aerodynamic efficiency and dynamic stability while exhibiting only a moderate increase in drag associated with the external energy-storage system. The investigated configuration therefore represents a viable candidate for future studies involving hybrid-electric and fully electric propulsion architectures. The present work establishes a preliminary framework for multidisciplinary investigations combining aerodynamics, structures, flight mechanics, and propulsion system integration.
Octavian-Mircea Crisan, Alexandru Pasula· Romanian Journal of Technica...· 0 citations
