Browse Topic: Entry, descent, and landing
There are certain situations when landing an Advanced Air Mobility (AAM) aircraft is required to be performed without assistance from GPS data. For example, AAM aircraft flying in an urban environment with tall buildings and narrow canyons may affect the ability of the AAM aircraft to effectively use GPS to access a landing area. Incorporating a vision-based navigation method, NASA Ames has developed a novel Alternative Position, Navigation, and Timing (APNT) solution for AAM aircraft in environments where GPS is not available
Innovators at NASA Johnson Space Center have developed and successfully flight tested a high-performance computing platform, known as the Descent and Landing Computer (DLC), to suit the demands of safe, autonomous, extraterrestrial spacecraft landings for robotic and human exploration missions
Batteries for eVTOL aircraft need to deliver high power for efficient takeoff and landing, as well as high energy for the cruise period. To meet these demands, designers must consider the power-energy tradeoff of batteries and integrate a reliable battery management system into the overall design. Multiphysics simulation can be used to evaluate this tradeoff and consider all design requirements in a way that is comprehensive and saves time. In recent years, more and more organizations have announced their development of electric vertical take-off and landing (eVTOL) systems and, in some cases, are even showing previews of systems that are intended to hit the market in just a few years. As new design ideas emerge, there is one important question that needs to be asked: To keep up with the developments in eVTOL aircraft, what design requirements need to be considered for the batteries that power them
With regards to any aerospace mission, it is very useful to have awareness about the state of vehicle, i.e., the information about its position, velocity, attitude, rotational rates and other concerned data such as control surface deflections, landing gear touchdown, working of mechanisms and so on. The sensor data from the vehicle that is communicated to the ground can be difficult to perceive and analyze. A frame work for real-time motion simulation of an aerospace vehicle from onboard telemetry data is henceforth developed in order to improve the understanding about the current state of the mission and aid in real-time decision making if required. The telemetry data, that is transmitted through User Datagram Protocol (UDP), is received and decoded to usable format. The visualization software accepts the data in a fixed time interval and applies the required transformations in order to ensure one-to-one correspondence between actual vehicle and simulation. The transformations
A structural load estimation methodology was developed for RLV-TD HEX-01 hypersonic experimental mission, the maiden winged body technology demonstrator vehicle of ISRO. Primarily the method evaluates time history of station loads considering effects of vehicle dynamics and structural flexibility. Station loads of critical structures are determined by superposition of quasi-static aerodynamic loads, dynamic inertia loads, control surface loads and propulsion loads based on actual physics of the system, improving upon statistical load combination approaches. The technique characterizes atmospheric regime of flight from vehicle loads perspective and ensures adequate structural margin considering atmospheric variations and system level perturbations. Features to estimate change in loads due to wind variability and atmospheric turbulence are incorporated into the load estimation methodology. Augmentation in loads due to structural flexibility is assessed along the trajectory using vehicle
In commercial aerospace, the application areas for motors are wide and varied, each with their own unique requirements. From electric vehicle take-off and landing (eVTOL) air taxis to business jets to long-haul commercial transport aircraft, DC motors must endure various environmental conditions like extreme temperatures, shock and vibration, atmospheric pressures and signal interference, to name just a few. These applications may also demand motors that provide a fast response, high power or torque density. In addition to these requirements, the aerospace industry perpetually calls for lightweight materials and smaller installation spaces. Taken together, it can be very difficult to specify and buy a reliable motor for mission-critical equipment. This article will present common commercial aerospace applications that pose performance and environmental challenges for DC motors along with a summary of the stringent aerospace industry standards that the motors must satisfy. It will also
Lunar landing and launch pads represent critical infrastructure for enabling a sustained presence on the Moon or other planetary bodies. Such a Moon presence would require repeated lunar landings and takeoffs, preferably near an outpost or habitat. In the absence of takeoff and landing pads, such vehicles could project lunar regolith at high velocities, sandblasting the surrounding infrastructure and causing damage
Direct debugging of a vertical takeoff and landing (VTOL) fixed-wing aircraft’s control system can easily result in risk and personnel damage. It is effectively to employ simulation and numerical methods to validate control performance. In this paper, the attitude stabilization controller for VTOL fixed-wing aircraft is designed, and the controller performance is verified by MATLAB and visual simulation software, which significantly increases designed efficiency and safety of the controller. In detail, we first develop the VTOL fixed-wing aircraft’s six degrees of freedom kinematics and dynamics models using Simulink module, and the cascade PID control technique is applied to the VTOL aircraft’s attitude stabilization control. Then the visual simulation program records the flight data and displays the flight course and condition, which can validate the designed controller performance effectively. It can be concluded that the designed VTOL fixed-wing aircraft control visual simulation
NASA’s Langley Research Center Hampton, VA
The aerospace industry is undergoing a revolution with the large-scale development of eVTOL (Electric Vertical Take-Off & Landing) and MEA (More Electric Aircraft). These aerial vehicles, many of them unmanned vehicles (UAV), will serve a variety of service-related functions: Search and Rescue (SAR), Medivac, delivery and lift operations, aerial mapping, and, of course, human transportation [1]. Despite its numerous functionalities, this type of vehicle has a serious problem, which is its usual batteries, the main means for its operation. Due to its autonomy not being so effective compared to its charging time, generating a considerable loss of time. In this context, it is necessary to find forms of components that can replace these batteries, so that the effective development of these vehicles is possible. Studies done in other means of transportation point out that the use of hydrogen fuel cells has grown a lot. In this way, it is known that this type of fuel is seen as something of
Under the emerging urban air mobility (UAM) concept, electric vertical take-off and landing (eVTOL) aircraft were designed to alleviate urban traffic congestion due to their advantages of low take-off and landing site requirements, less pollution, low noise, and strong stability. However, due to the high-level power consumption of eVTOL and only having air flight mode, this kind of aircraft has a severe shortage of cruising range. To improve the endurance and dynamic performance, the flying car designed in this paper added a ground driving mode based on eVTOL and used distributed ducted fans to provide lift. And the influence of different power transmission routes on the dynamic and economic performance of the flying car was analyzed. On this basis, the overall take-off weight of the flying car was estimated through an iterative algorithm, and parameter design and power system matching for each part of the components were conducted. Finally, this paper used MATLAB/Simulink to build a
There’s no question that significant amounts of power are needed for electric-powered vertical takeoff and landing (eVTOL) aircraft to become airborne and maintain flight. But designers of rotorcraft and personal air vehicles (PAVs) have many questions about what kinds of electrical interconnects can handle the required voltages and kW peak output for electric propulsion motors, inverters, controllers, batteries, infotainment, and sensors. To make eVTOL a reality, designers must identify the proper connectivity solution and implement a “follow-the-wire” design approach to overcome the following challenges
There's no question that significant amounts of power are needed for electric-powered vertical takeoff and landing (eVTOL) aircraft to become airborne and maintain flight. But designers of rotorcraft and personal air vehicles (PAVs) have many questions about what kinds of electrical interconnects can handle the required voltages and kW peak output for electric propulsion motors, inverters, controllers, batteries, infotainment, and sensors. To make eVTOL a reality, designers must identify the proper connectivity solution and implement a “follow-the-wire” design approach to overcome the following challenges
Conventional high-lift systems allow transport aircraft to safely operate at low speeds for landing and takeoff. These high-lift devices, such as Fowler flaps, are complex, heavy, and have high part counts. Fowler flap mechanisms also protrude externally under the wings, requiring external fairings, which increase cruise drag. Simple-hinged flaps are less complex, and an ideal choice for low-drag cruise efficiency. However, simple-hinged flaps require high flap deflections to achieve lift comparable to Fowler flaps. These flap deflections cause severe adverse pressure gradients, which generate flow separation that is difficult to control. In response to these challenges, NASA developed the High Efficiency Low Power (HELP) active flow control (AFC) system
WaveBand, as part of a Dual Use and Science and Technology Contract in partnership with the Federal Aviation Administration and the US Air Force Research Laboratory at Rome, NY, developed a 94 GHz radar to detect birds at airports and airfields that could potentially interfere with the landing and takeoff of aircraft. The requirements for the radar system were summarized as follows
Recent advancements of electric vertical takeoff and landing (eVTOL) aircraft have generated significant interest within and beyond the traditional aviation industry, and many new and novel applications have been identified and are under development. One promising application is rapid response during natural disasters, which can complement current capabilities to help save lives and enhance post-disaster recoveries. The Use of eVTOL Aircraft During Natural Disasters presents issues that need to be addressed before eVTOL aircraft are integrated into natural disaster response operations: eVTOL vehicle development Detect-and-avoid capabilities in complex and challenging operating environments Autonomous and remote operations Charging system compatibility and availability Operator and controller training Dynamic air space management Vehicle/fleet logistics and support Acceptance from stakeholders and the public Click here to access the full SAE EDGETM Research Report portfolio
We demonstrate a virtual proof-of-concept design and experiment for energy harvesting enabling economic and environment-friendly aircraft by recycling forces for power conversion. The harvesting uses piezoelectric materials for extracting energy from the impact at the touchdown during the landing of an aircraft and direct current (DC) generators powered by the rotational motion of the aircraft wheels during taxiing. The design begins with a multidomain model comprising multibody dynamics, mathematical descriptions, abstract behavioral blocks, and programmed code. Piezoelectric harvesting explores six types of materials consisting of ring and disk pad geometries. Both geometries are typical configurations in suspension systems. Recent advances have shown the potential of getting higher voltage out of new materials properties. Our objective is to determine the useful impact force during a touchdown on the pads and a pad type that maximizes the power transfer. The evaluation shows that
Urban air mobility (UAM) refers to urban transportation systems that move people by air. UAM offers the potential for reducing traffic congestion in cities and providing an integrated approach to urban mobility. With the emergence of electric vertical takeoff and landing (eVTOL) aircraft, drone technology, and the possibility of automated aircraft, interest in this topic has grown considerably for private sector solution providers—including aerospace and technology companies—as well as urban planners and transportation professionals. Unsettled Issues Concerning Urban Air Mobility Infrastructure discusses the infrastructure requirements to effectively integrate UAM services into the overarching urban transportation system to enable multimodal trips and complete origin to destination travel. Click here to access the full SAE EDGETM Research Report portfolio
Thermoplastic composite materials (TPC) are gaining momentum for use in commercial airplanes and other aerospace applications, including electric vertical takeoff and landing (eVTOL) aircraft. TPC were once considered too expensive for applications other than small components. Now, material and processing advances are propelling TPC into the aerospace industry spotlight
Thermoplastic composite materials (TPC) are gaining momentum for use in commercial airplanes and other aerospace applications, including electric vertical takeoff and landing (eVTOL) aircraft. TPC were once considered too expensive for applications other than small components. Now, material and processing advances are propelling TPC into the aerospace industry spotlight
Recent advancements of electric vertical takeoff and landing (eVTOL) aircraft have generated significant interest within and beyond the traditional aviation industry. One promising application for these innovative systems is in firefighting support during urban, rural, and wildland firefighting operations. Future eVTOL firefighting capabilities could include early detection and suppression, civilian rescue, and on-demand aerial deployment and extraction of firefighters. Unsettled Issues Concerning eVTOL for Rapid-response, On-demand Firefighting identifies the challenges to be addressed so that these capabilities and benefits could be realized at scale: Firefighting-specific eVTOL vehicle development Sense and avoid capabilities in smoke-inhibited environments Autonomous and remote operating capabilities Charging system compatibility and availability Operator and controller training Dynamic air space management Vehicle/fleet logistics and support First-responder and general public
In the final few minutes of a spacecraft landing, it is moving at hypersonic speed through many layers of atmosphere. Knowing the air density outside the vehicle can have a substantial effect on its angle of descent and ability to hit a specific landing spot. But air density sensors that can withstand the harsh hypersonic conditions are uncommon. Researchers developed an algorithm that can run onboard a vehicle, providing important real-time data to aid in steering the craft, particularly during the crucial entry, descent, and landing stage
This report identifies the reasons for, and results associated with, the conduct of a flight simulation research project evaluating the effect of low powered laser beam illumination of pilot crewmembers operating in the navigable airspace. This evaluation was primarily concerned with the possible degradation of pilot performance when illuminated by a laser while operating in an airport terminal area where pilot workloads are normally at their maximum
This document addresses the operational safety and human factors aspects of unauthorized laser illumination events in navigable airspace. The topics addressed include operational procedures, training, and protocols that flight crew members should follow in the event of a laser exposure. Of particular emphasis, this document outlines coping strategies for use during critical phases of flight. Although lasers are capable of causing retinal damage, most laser cockpit illuminations, to date, has been relatively low in irradiance causing primarily startle reactions, visual glare, flashblindness and afterimages. Permanent eye injuries from unauthorized laser exposures have been extremely rare. This document describes pilot operational procedures in response to the visual disruptions associated with low to moderate laser exposures that pilots are most likely to encounter during flight operations. With education and training, pilots can take actions that safeguard both their vision and the
The recommendations of this document apply to such aircraft as are able to perform both normal angle and steep IMC approaches, the latter being defined as those approaches having a final approach segment angle greater than 4°. Such aircraft can include both conventional and STOL fixed-wing aircraft, commercial air transport and/or utility and normal category helicopters, compound helicopters and powered lift vehicles (tiltrotors, tiltfans, tiltwings, etc
A modular vertical takeoff and landing (VTOL) unmanned aerial system (UAS) is made up of multiple unmanned aerial vehicle (UAV) modules with uniform wingtips for tip-to-tip docking. Each UAV has twin booms with front and rear propellers and an empennage with a downward-mounted vertical rudder. All the propellers are tiltable for VTOL and the front ones are stowable for cruise efficiency
This Glossary is designed to serve persons who need to know the accepted meanings, within specific contexts, of the terminology used in reports, articles, regulations, and other materials dealing with aviation safety -- with particular reference to terms specific to human factors in aviation safety. It is assumed that some users of the Glossary will be familiar with the nomenclature of aviation, but will need information on the language of human factors in engineering as they apply to aviation safety. Others (for example, engineers and psychologists) will have fairly extensive knowledge of the terminology of their own and related disciplines, but will need authoritative definitions of technical terms specific to aviation. Within the foregoing general framework, the following guidelines for the inclusion of terms to be defined have been observed
Recent advancements of electric vertical takeoff and landing (eVTOL) aircraft have generated significant interest within and beyond the traditional aviation industry, and many new and novel applications have been identified and under development. The COVID-19 crisis has highlighted the challenges of managing a global pandemic response due to the difference in regional and local resources, culture, and political systems. Although there may not be a uniform crisis management strategy that the world can agree on, we can leverage a new generation of vertical flight vehicles to make a difference if (or when) such a global epidemic strikes again. One of the key challenges realized in the early stage of the COVID-19 outbreak is the ability to allocate and distribute limited and critical medical resources, including equipment, supplies, medical personnel, and first responders to the hot spots when and where they may be needed. The on-demand logistics capabilities could be enhanced by the
The levels of voltage and current needed in electric-powered vertical takeoff and landing aircraft (eVTOL), personal air vehicles (PAVs), and rotorcraft systems are high and going higher. That's because electric propulsion motors, inverters, controllers, batteries, and sensor-laden electric aircraft require significant amounts of power. High voltages and high kW peak outputs present many implementation challenges. Designers can meet these challenges by understanding how proper product selection and a “follow-the-wire” design approach enable high-power connectivity solutions. Some of the hurdles that designers need to overcome include the following
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