Take-off Distance Research Articles

Reducing take-off and landing distances for regional turboprop aircraft

Reducing take-off and landing distances for regional turboprop aircraft

Vectored-thrust system design for a tail-sitter micro-aerial-vehicle with belly/back takeoff ability

The tail-sitter configuration has the advantage of being capable of vertical takeoff and landing. However, it may confront takeoff and landing difficulties in an atmosphere environment with gusts, especially for the miniature design of micro-aerial-vehicles (MAVs). Typically, a tailer-sitter can takeoff from an erect posture, if it falls down accidentally, it is difficult to restore its original start-up posture without human involvement. To address this problem, a novel design method for a tail-sitter MAV has been introduced with unique takeoff and landing modes, which enable it to fly from any start-up attitude. The key design parameters are provided and tested using flight dynamics simulation modelling. It is found that, the takeoff distance is closely related to the moment arm, maximum deflection angle, and servo deflection rate of a vectored-thrust system, based on which the minimum value of altitude command can also be defined. A flight test of prototype has been conducted to verify the feasibility of the design method proposed in the current study.

Aerodynamic Analysis of a Logistics UAV with Foldable Bi-wing Configuration

Herein, a twin-boom, inverted V-tailed unmanned aerial vehicle (UAV) featuring a foldable bi-wing configuration is proposed for logistics and transportation applications. We employed the Navier–Stokes solver to numerically simulate steady, incompressible flow conditions. By examining the effects of key design parameters on aerodynamic characteristics and bypass flow fields in a two-dimensional state, we were able to suggest a more optimized foldable wing design. Building on the two-dimensional analysis, we performed aerodynamic assessments of the three-dimensional aircraft geometry. Our results indicated that appropriate wing and gap parameters can significantly enhance lift characteristics, maintaining high lift even during large-angle flights. Specifically, when compared to a mono-wing, the lift coefficient of the bi-wing increased by 27.1% at a 14° angle of attack, demonstrating the effectiveness of our wing-and-gap design. Optimal aerodynamic performance was achieved when the gap distance equalled the chord length in both flow and vertical directions. Further, the right combination of airfoil configuration, wing axes angle, and wingspan can improve flow field aerodynamic characteristics, while also enhancing the wing’s stall capacity. The lift coefficient reached its maximum value at an angle of attack of 15°, which has the potential to reduce takeoff and landing distances, thereby enhancing the UAV’s overall safety.

Design and fabrication of a fixed-wing Unmanned Aerial Vehicle (UAV)

Unmanned Aerial Vehicles (UAVs) have been widely used both in military and civil across the world in recent years. Nevertheless, their design always involves complex design optimization variables and decisions. Therefore, this paper aims to guide through the designing, manufacturing, and testing of an electrically powered radio-controlled aircraft for achieving a take-off, cruise, safe landing and carrying the highest payload possible. The whole process involves several phases, design phase, structural analysis, performance analysis, materials used, manufacturing, and finally aircraft testing. The final aircraft was designed with an empty weight and maximum take-off weight of 15.43 Ibs and 33.07 Ibs respectively while the wingspan, cruising speed and maximum speed were 70.1 in., 46 ft/s and 78 ft/sec respectively with a total take-off distance of 100 ft.

Characteristics of water jump for better performance in collegiate male 3000 m steeplechase.

The 3000 m steeplechase consists of 28 barriers and seven water-jumping obstacles. The water jump in the 3000 m steeplechase makes it different from the sprint hurdle events. It is important for coaches and athletes to understand how to clear the water jump successfully. I aimed to investigate whether the takeoff and landing distances for the water jump per lap differ between participants with good and worse records. Data were collected from the men's 3000 m steeplechase races (heats) at Kanto Intercollegiate race. A total of 48 men's performances were analyzed (24 upper group, 24 lower group). Takeoff distance, landing distance and clearance time were analyzed. Takeoff distance, landing distance, total water jump distance and clearance time were subjected to mixed two-way ANOVAs with repeated factors of Lap (lap 1/lap 2/lap 3/lap 4/lap 5/lap 6/lap 7) with Group (upper group/lower group) as a between group factor. Takeoff distance was longer for upper group (1.43 m) than lower group (1.34 m) (p=.01). Landing distance was longer for upper group (2.95 m) than for lower group (2.74 m) (p=.01) and was longer for lap 1 (2.95 m) than last three laps (lap 5: 2.83 m, lap 6: 2.82 m, lap 7: 2.76 m) (p=.01). Individuals who were faster in 3000 m steeplechase exhibited longer water jump distance. The effect of fatigue might be greater for landing distance than for takeoff distance. Because the landing distance becomes shorter in the second half of the 3000m steeplechase, it is important to note that athletes should aim to land as far away from the water pit as possible.

Design optimization to minimize wake of wide-body transport aircraft

A cutting-edge sustainable airplane can improve performance and enhance profitability are the most significant future concerns for the aviation industry. This research aims to analyse and assess aircraft performance of mid-size transport aircraft through retrofit designs. An optimal design was employed using a non-linear optimization approach under two cases fuselage alone (case 1) and a combination of fuselage-wing-empennage (case 2). These two retrofit concepts were evaluated and compared with the baseline A310–200 aircraft. To compute the objective function for various cases, non-linear solver was used from MATLAB optimization tool box. Additionally, the parametric studies of aerodynamics, structural and operational performance analysis are carried out by using Advanced Aircraft Analysis (AAA) 5.0 software. Sensitivity analyses are performed to assess the overall effectiveness of the optimal design. The key findings of this paper obtained the following parameters as Maximum take-off Weight, empty weight, fuel weight, parasite drag coefficient, rate of climb, take-off distance and landing distance are improved by 0.36%, 26.02%, 10.12%, 4.48%, 27.24%, 13.13% and 9.2% respectively. At the end, the paper provides a clear statement on the managerial perceptions and future insights for the upcoming challenges towards sustainable design.

Aviation and Climate Change: Challenges and the Way Forward

There is a broad scientific consensus that the phenomenon of global warming is very likely driving a global climate change. There is also a developing understanding that climate change and air transport have a two-way relationship. This paper aims to identify the possible impacts of climate change on the aviation sector and to discuss adaptation plans that will address the vulnerabilities and will ensure safe aviation-related operations. Climate change is known to cause disruptions in airport operations due to greater and more frequent temperature extremes and changes in precipitation and wind that are very possible to demand increased take-off distances and decreased climb rates. Extreme rainfall and rising sea levels may threaten coastal and low-lying airports with flooding. Changes in biodiversity and wildlife patterns intensify the bird strike hazard. Disruptions also occur in air operations. Increasingly frequent extreme weather events are responsible for air traffic delays. Changing atmospheric patterns and icing conditions challenge aircraft performance and rise flight duration and flight costs. The above risks may have a direct impact on travel and tourism, affecting destination favorability and the duration of the tourism season. All the above concerns call for urgent actions from the policymakers and the industry. Adaptation measures include the development of risk-assessment frameworks and action plans for the major stakeholders, technology advancements to deal with gas emissions and oil depletion, long-range infrastructure planning and investment, the introduction of climate-related regulations, as well as raising awareness and promoting collaboration as key steps in building climate change resilience for the global aviation sector.

Grid-based many-objective optimiser for aircraft conceptual design with multiple aircraft configurations

This paper presents an aircraft conceptual design technique with more than three objective functions, called many-objective optimisation. The selection of aircraft configuration is usually achieved using a system engineering approach. This selection approach has the design variables assigned to remove the configuration decision-making process. The design problem is demonstrated for the conceptual design of a fixed-wing unmanned aerial vehicle. Eight objective functions, including power required, take-off weight, take-off distance, landing distance, endurance, range, lift coefficient at cruise and drag coefficient at cruise, are posed, while the constraints are aircraft stability, performance required and take-off distance. Design variables simultaneously determine an aircraft configuration, shape and sizing parameters. Hence a new, many-objective metaheuristic is developed to increase the design performance. A grid-based many-objective metaheuristic with iterative parameter distribution estimation (MM-IPDE-Gr) is developed. It is an enhanced variant of the MM-IPDE with improved reproduction schemes, adaptive parameters and a grid-based clustering technique. Several additional reproduction schemes in mutation and crossover processes with two additional adaptive parameters are integrated to increase population diversity and improve the exploration ability of the algorithm. In addition, the grid-based method is integrated as a clustering technique to improve the Pareto clustering process in many-objective optimisation. The proposed method, with established newly invented metaheuristics, is used to solve the new design problem and its performance compared with existing design methods. It is shown that the proposed many-objective metaheuristic gives the best results.

Ungulate responses and habituation to unmanned aerial vehicles in Africa's savanna.

This article tests the hypothesis that "the likelihood that the species will react and level at which they do to the unmanned aerial vehicle (UAV) is related to the altitude, number of passes, sound intensity, type of UAV, takeoff distance, and species." This paper examined the behavioral responses of a group of free ranging ungulate species (Oryx, Kudu, Springbok, Giraffe, Eland, Hartebeest, and Impala) found in an animal reserve in Namibia to the presence of different in-flight UAV models. The study included 397 passes (trials) over 99 flights at altitudes ranging from 15 to 55 meters in three categories of response level: No response, Alert, and Movement. The ungulates were unhabituated to the UAVs and the study was conducted in the presence of stress-inducing events that occur naturally in the environment. Certain species were found to be more reactive than others, in addition to several displaying different response levels in single or mixed herd environments. Zebras were found to be less responsive in mixed herd environments while Oryx were present, as compared to when the Oryx were not; suggesting that some species may respond based on other species perception of threat or their relative fitness levels. The UAVs also produced inconsistent response rates between movement and alert behavior. The reference vehicle, Phantom 3 was much more likely than the Mavic to induce an alert response, while both having similar probabilities of inducing a movement response. Furthermore, the Custom X8 showed significantly more alert and movement responses than the other UAVs. This shows there may be several aspects to the UAVs that affect the responses of the ungulates. For instance, the sound intensity may alert the species more often, but close proximity may induce a movement response. More generally, the data shows that when the UAV is flying above 50 meters and has a measured sound intensity below 50 dB, the likelihood of inducing a movement response on an ungulate species is below 6% regardless of the vehicle on the first pass over the animals. Additionally, with each subsequent pass the likelihood of response dropped by approximately 20 percent. The results suggest a stronger correlation between flight altitude and response across the different ungulates, and the evidence suggests rapid habituation to the UAVs.

Design, manufacturing and flight-testing of a fixed-wing, small-scale UAV for the transportation of blood bags to remote locations

The current work presents the design, manufacturing, and flight-testing of a fixed-wing, small-scale Unmanned Aerial Vehicle (UAV). The research activities presented in this paper have all been conducted by the Aristotle Space & Aeronautics Team (ASAT), a Greek aerospace student team, for their participation in the international student competition Air Cargo Challenge 2022. Its mission is to carry bags of blood to a remote location. The design requirements refer to a short take-off distance of 60m of rough terrain, climb time of 60s and a cruise/loiter time of 120s. Size restrictions also apply, as the aircraft must fit inside a 1.5m x 1.5m x 0.5m volume, in its deployed form. A step-by-step presentation of the design procedure is conducted, emphasizing on the critical design decisions, such as the airfoil, cargo bay location and wing planform design. The corresponding trade studies are shown, along with the main advantages of the resulting configuration. The in-house manufacturing process is consequently described, focusing on the molds tooling, as well as on the carbon fiber and fiberglass manufacturing techniques. Finally, the results of the flight testing are shown, including the initial challenges that lead to the fine-tuning of the UAV. The test results are validated against the design data and the overall performance of the aerial vehicle is discussed.

VR-Supported Analysis of UAV—Magnetic Launcher’s Cart System

The subject of the research is a model of a magnetic launcher, which is an innovative alternative to commercially occurring unmanned aircraft launchers (UAV). As the take-off is an energy-demanding phase of the flight; therefore, abandoning the power supply of the UAV during this phase significantly affects increasing the potential range and duration of UAV flight. The magnetic launcher offers the significant advantage of minimizing friction between the starting cart and the launcher, resulting in the higher energy efficiency of the system. Research conducted so far has shown that the possibility of accelerating the aircraft on the longer runway offered by the launcher reduces aircraft overloads occurring during take-off. As a result, the launcher, aircraft, and onboard equipment are much safer. This paper presents the system’s mathematical modeling and numerical simulation results for micro-class UAV take-off and landing using the analyzed magnetic launcher. The computer program for analyzing system dynamics was implemented in the MATLAB environment. Simulation results were visualized graphically and as animations in Virtual Reality. The VR application was implemented in Unity and ran on VR goggles Oculus Quest2. The simulations carried out show that—in the absence of control—an important factor reducing the takeoff distance and affecting the aircraft load is the adoption of a non-zero takeoff thrust of the UAV. The initial pitch angle also has a significant impact on the takeoff process. With an increase in this parameter, the length of the takeoff distance decreases and the lift-off speed decreases, but too much pitch angle may result in the aircraft descending in the first moments of flight, which could lead to a collision with the launch rails.

An examination of kinematic parameters related to pole vault performance

ABSTRACT Although various studies have examined factors associated with pole vault performance, only a few have identified a linear relationship between these factors and performance. This study aimed to identify the kinematics variables correlating with the maximum centre of gravity (CG) height. This cross-sectional study included 16 male pole vaulters and recorded their performance using four high-speed cameras at 240 Hz. The vaulters cleared the bungee bars that were set at 90% of their personal best record. The variables during pole vaulting from the touchdown of the penultimate step on the approach to the peak height of the CG were calculated. Pearson’s correlation analysis and Spearman’s rank correlation were used to test the correlation between maximum CG height and the variables. Significant correlations were observed between the maximum CG height and the six variables (grip height, approach velocity, takeoff velocity, takeoff distance, push height, and maximum vertical velocity). Grip height showed the strongest relationship, followed by push height and takeoff velocity. Pole vaulters should aim to gain a high approach velocity and grip height to increase their mechanical energy.

Modeling and verification of helicopter roll-on takeoff based on optimal control theory

Purpose The paper aims to establish a comprehensive optimization analysis model for a helicopter roll on the ground and take off based on optimal control method. The trajectory and control of the entire process are studied, and the key factors affecting the helicopter takeoff distance are analyzed. Design/methodology/approach First, based on the equivalent stiffness and damping, the landing gear model is established, and a six-degree-of-freedom helicopter model is formed. Then, the simulation of the roll-on takeoff is transformed into a nonlinear optimal control problem (NOCP). Meanwhile, a hybrid single-multiple shooting method-based transcription process is used for discretizing the problem, leading to a finite nonlinear programming model, which is solved by sequential quadratic programming. Finally, the process was calculated and compared with flight test data, which verified the feasibility of the NOCP. The influence of takeoff weight, takeoff power and liftoff airspeed on the takeoff distance of the helicopter was analyzed. Findings The results show that the takeoff weight can be increased by 17% under the maximum takeoff power, which is roll-on takeoff at an altitude of 0 m. When the helicopter takes off with the maximum weight at an altitude of 5000 m, the liftoff airspeed should be over 49.2 km/h. Originality/value The novelty of this paper lies in the comprehensive consideration of helicopter taxiing and taking-off phases, and the application of optimal control theory to establish a comprehensive analysis model, which can quickly analyze the maximum takeoff weight, takeoff distance, optimal liftoff speed and so on. Meanwhile, the method is verified based on the flight data.

Assessment on fuel economy of MoM transport aircraft using empirical approach: modelling with a case study

Purpose This research is associated with the real-time parameters of wide- and narrow-body aircraft to recognize the quantitative relationship framework. This paper aims to find the superiority of aircraft design technology which triggers the reduction in specific fuel consumption (SFC) and economic competitiveness. Design/methodology/approach The real case study is performed with 22 middle-of-the-market (MoM) aircraft. This paper develops a fuel burn mathematical model for mid-size transport aircraft by a multi-linear regression approach. In addition, sensitivity analysis is performed to establish the authentication of the fuel burn model. Findings The study reveals that the MoM aircraft would be the future aircraft design in terms of better fuel economy and carbon footprint. From the multi-regression analysis, it is observed that the logarithmic regression model is the best fit for estimating the SFC. Moreover, fineness ratio, aspect ratio, gross weight, payload weight fraction, empty weight fraction), fuel weight fraction, payload, wing loading, thrust loading, range, take-off distance, cruise speed and rate of climb are observed as the suitable parameters which provide the best fitness value as 0.9804. Originality/value Several existing literature reveals that a few research has been performed on the MoM aircraft with wide-body configuration. Moreover, mathematical modelling on the fuel consumption was insignificantly found. This study examines several parameters which affect the fuel consumption of a wide-body aircraft. A real-case study for design configurations, propulsive systems, performance characteristics and structural integrity parameters of 22 different MoM aircraft are performed. Moreover, multi-regression modelling is developed to establish the relation between SFC and other critical parameters.

Evolution of high-temperature extremes over the main Euro-Mediterranean airports

The increasing intensity and frequency of high-temperature events in response to climate change can potentially impact the aviation industry, since aircraft takeoff and landing performances depend on near-surface air temperature. Previous studies have combined climate data with aircraft technical data to estimate the future impact of rising high temperatures on aircraft takeoff. They found a decrease of maximum takeoff weights and the lengthening of takeoff distances. The Mediterranean region is a climate change “hot spot” area, specially concerned by extreme high-temperatures increase. In this study, the magnitude and trends of the daily maximum near-surface temperature extremes in summer were analysed over major airports in Southwestern Europe. Trends in the period 1961–2014 were analysed from observations and reanalysis. Future changes by 2021–2050 and 2071–2100, with respect to 1961–2005, were analysed from simulations performed with Regional and Global Climate Models (RCMs and GCMs). Before assessing future climate projections, climate models were evaluated in present climate, and the RCM and GCM ensembles were compared to each other. No clear added value was found for RCMs over GCMs in present climate at the airport scale in these terms. GCMs project larger temperature changes than RCMs over the same locations. Multi-model ensemble mean projected changes under the RCP8.5 scenario range between + 1.7 and + 3.2 ^{circ }C by the near term, and between + 4.9 and + 8.5 ^{circ }C by the long term, across the airports and the RCM and GCM ensembles. This increase of high-temperature extremes would impact airport operations. Adaptation or mitigation policies would become necessary.

Decreased Aircraft Takeoff Performance under Global Warming

With global warming, extreme high temperatures become more frequent and are an important factor affecting aircrafts’ takeoff performance. Using Community Earth System Model version 1 (CESM1) and Boeing Performance Software (BPS), the influence of increasing temperature on aircrafts’ maximum takeoff weight (MTOW) and takeoff distance is evaluated quantitatively in this study. The results show that the distribution of summer daily maximum temperature shifts obviously to higher temperature at all the chosen airports and the variation in temperature is larger at four airports (Jinan, Shanghai, Lhasa, and Urumqi) during 2071−2080 under the RCP8.5 scenario than that in the historical run (1991−2000). The warming air leads to the MTOW reducing and takeoff distance increasing. Taking the Boeing 737–800 aircraft as an illustration, the number of weight-restriction days increases significantly across the airports, which can influence airlines’ economic benefit and flight operations in the future. It is also found that the takeoff distance does not change linearly with temperature, but shows a stronger increase with higher temperature. The takeoff distance increases about 6.2% on average during 2071−2080 compared to 1991−2000 for the low-altitude airports, calling for an additional 113−222 m takeoff distance in future summers.

On the steady-state motion in the vertical plane of an airship of the classical scheme

We consider the construction of the mathematical model of motion in the vertical plane of an airship of the classical scheme and algorithms for calculating the parameters of its steady-state motion in various cases. The motion of an airship of rather small volume, for example, a remotely piloted airship, is investigated. Some types of possible motions in the vertical plane satisfying the proposed system of equations of steady-state motions are described. Such motions include horizontal flight with constant velocity, rectilinear flight in climbing mode, and descent at a constant trajectory slope angle. The cases of rectilinear flight of an airship along inclined trajectories, the inclination angle of which is not small, taking into account the nonlinear components of the aerodynamic characteristics, are also considered. We have developed algorithms for calculating the steady-state motions of an airship for various cases of flight along inclined trajectories corresponding to various methods of takeoff and landing of an airship without a special cable landing system. This allows us to construct trajectories that provide short takeoff distances and low landing speeds of the airship, which corresponds to the solution of the problem of safe operation of the airship as a technical system. The results of numerical calculations of steady-state motion parameters obtained in accordance with the constructed algorithms are presented. The calculation results are presented graphically.

Takeoff runway overrun risk assessment in aviation safety based on human pilot behavioral characteristics from real flight data

Aviation safety is an important part of safety science and pilot behavior is a major factor in flight safety analysis. However, when analyzing unsafe events, such as runway overrun, majority of studies do not quantify the impact of pilot behavior on flight safety. The aim of this paper is to discover the pilot behavioral characteristics from actual flight data and apply them to construct a takeoff runway overrun risk assessment model. Concretely, the time series clustering is used to mine the pilot behavioral characteristics based on pilot operating data. Then, the similarity theory is introduced to construct a data-based man–machine-environment system expression including pilot behavioral characteristics to get the takeoff distance for the runway overrun risk assessment. The results of case study showed that 3 types of pilot behavioral characteristics were found in selected fleet, which mainly differ in the pilot reaction time after VR and operation input speed of the control column, and RO is more likely to happen under the combined influence of longer reaction time and slower operation input speed. The proposed method makes full use of real flight data from airlines under different conditions incorporating pilot behavior characteristics and can inform risk analysis of other unsafe events such as hard landing, tail strike, etc.

Kinematic Factors Associated with Hitting Hurdles During the Initial Phase of a 110-m Hurdle Race.

This study aimed to clarify the kinematic factors for the cause and effect of hitting hurdles during the initial phase of a 110-m hurdle run. Nine experienced male hurdlers participated in this study (body height: 1.74 ± 0.04 m, body mass: 67.4 ± 5.9 kg, age: 20.2 ± 1.4 years, personal best: 15.21 ± 0.47 s, seasonal best: 15.33 ± 0.55 s). Hurdlers undertook 12 trials of the initial phase of hurdling from the start to the second hurdle landing. Dual-sided sagittal plane motion was obtained from images from two high-speed cameras operating at 120 Hz. One ‘hit’ trial which had the largest horizontal displacement of markers fixed on the hurdle and one ‘non-hit’ trial which had the fastest time of hurdle clearance were extracted for each participant. Kinematic variables were compared between the two trials. Significantly lower height of the whole-body centre of mass at the take-off was found as a possible cause of hitting hurdles, caused by insufficient swing-up of the lead leg thigh. In contrast to conventional understanding, take-off velocity, take-off distance and the take-off angle were comparable between the ‘hit’ trial and ‘non-hit’ trial. Regarding the effect of hitting hurdles, it was observed that running velocity during hurdling was not substantially reduced. However, several characteristic movements were identified that might induce inefficient motion to re-accelerate running velocity during the following landing steps.

Short-takeoff marine vehicle with circulation flow control of wing-in-ground effect

The concept of active circulation control has been proposed to improve lifting performance for various applications. It is mostly suggested as a flow control system to replace or minimize mechanical flaps or as a boundary layer control mechanism in the aerospace industry. The efficiency of these systems has always been the main concern due to increased drag and pumping requirements. These concerns are negligible for high-speed marine crafts as the hydrodynamic drag acting on the hull is dominant. This research investigates the aerodynamic performance of a NACA 4412 airfoil that was modified for circulation control to determine the influence of the trailing-edge geometry, blowing coefficient, angle of attack, and height above the ground to improve the efficiency of a wing-in-ground craft and shorten its take-off distance. The flow is subsonic and incompressible, and the chord Reynolds number is 1.7 × 106. A computational fluid dynamics investigation has determined that significant increases in lift can be attained through circulation control relative to the original NACA 4412 airfoil, and it is not significantly influenced by the airfoil height except when there is an extreme ground effect. Also, the lift augmentation increases approximately linearly with the blowing momentum coefficient and angle of attack. The study shows a significant improvement in the take-off length, which was reduced from 465 m to between 360 and 150 m according to the height above the ground plane, angle of attack, and the momentum coefficient when the Coanda surface is 30 mm. The circulation-controlled NACA 4412 could achieve 66% effectiveness compared to a currently available vehicle.