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Aircraft
Published in Suzanne K. Kearns, Fundamentals of International Aviation, 2021
The energy density of aviation fuel is much higher than within a lithium-ion battery, which means that to produce the same power, an electric aircraft’s batteries would be about 40 times heavier than the fuel used to power a traditional aircraft. As aircraft all are limited to a maximum takeoff weight, this limits the practical payload capacity for cargo or passengers and significantly reduces the range. For example, for a transport-category jet aircraft, the fuel accounts for about 20 percent of the aircraft’s weight. If the aircraft were to be electrically powered, the required battery weight to fly across the Atlantic would be approximately 260,000 kilograms (573,000 pounds), which is four times the weight of the empty aircraft [24]! For this reason, today’s electric aircraft are small, light, and cover short distances.
Straight-level flight
Published in Mohammad H. Sadraey, Aircraft Performance, 2017
The significance of this performance criterion is appreciated when we consider the distance between cities and capitals of different countries. Each aircraft has limited range capabilities with specific speed and specific flight altitude. The flight with different flight conditions (e.g., altitude, speed) results in a different range. Therefore, when we are talking about range, it automatically means that the maximum range is with the best flight condition to provide the maximum range. The range of an aircraft at different altitudes is not the same. Similarly, the range of an aircraft with different speeds is not the same either. However, each aircraft has a unique maximum range with the maximum takeoff weight. This maximum range happens when flying at a specific (optimum) altitude and a specific (optimum) airspeed.
Design of rigid and flexible airfield pavements on cement-treated base
Published in Andreas Loizos, Imad L. Al-Qadi, A. (Tom) Scarpas, Bearing Capacity of Roads, Railways and Airfields, 2017
Carlo Rabaiotti, Danai Tsirantonaki, Marco Schnyder
The joint and material properties calibrated by inverse analysis of the EMPA tests were used in the model for Stands Echo Nord. The design aircraft for this part of the airport is ICAO code E aircraft (B777-300 ER) with 60% of the maximum takeoff weight. Three different loading positions were used: at the corner, at the edge and in the centre of the concrete slab.
GA-based offshore helideck design considering manufacturability and buckling safety
Published in Mechanics Based Design of Structures and Machines, 2023
Byungmo Kim, Kichan Sim, Chanyeong Kim, Seung-Hyun Ha
With respect to landing, Fasanella et al. (2001) researched a helicopter’s landing impact on a helideck. Vaghefi, Bagheri, and Mohebpour (2013) studied a helideck’s structural response triggered by vertical and horizontal landing loads under emergency landing conditions using pushover analysis. In particular, the helideck was simulated using SACS software under a vertical landing load, i.e., the maximum takeoff weight (MTOW), also known as maximum all-up weight (MAUW). For wind pressure, Chen et al. (1995) performed prototype tests for the offshore helideck in a wind tunnel. Through the experiments, wind velocity distributions dependent on wind directions and wind characteristics around the helideck, such as corner flow separation at the front, unsteady wind speed at the center, and significant wind speed variations from the center to the upper edge of the deck, were observed.
Recent research and development programs for infrastructures maintenance, renovation and management in Japan
Published in Structure and Infrastructure Engineering, 2020
Yozo Fujino, Dionysius M. Siringoringo
The overall weight of PRSS-UAV is equivalent to 2,583 g, which is about 92.25% of the maximum takeoff weight of the UAV. Similarly, the power rating of the system was more than doubled using a 7,800 mAH battery at 11.1 V. The system also provides easy maintenance by allowing the PRSS-UAV assembly to be split into two subassemblies. Detailed specification of PRSS-UAV system is given in Table 3. In this configuration, it is possible to easily remove and insert the UAV and other components inside the spherical shell if needed. The optimal size, weight, and configuration of the system was also designed for ease of transport and deployment.
Life-cycle analysis of electric vertical take-off and landing vehicles
Published in Transportation Planning and Technology, 2023
Khashayar Khavarian, Kara M. Kockelman
Other less important assumptions that do not directly affect cost calculations are the weights of each seat (assumed to be 15 kilograms), avionics (15 kilograms), each servo (just 0.6 kilograms), each wing tilt actuator (4 kilograms), and the ballistic recovery system (15 kilograms) (Lovering 2016). Since landing gear is about 2 percent of a helicopter’s maximum takeoff weight (Lovering 2016), a similar assumption is made here for each eVTOL. Such assumptions help with estimation of VTOL manufacturing and operating costs.