Equivalent running leg lengths require prosthetic legs to be longer than biological legs during standing by Janet H. Zhang-Lea, Joshua R. Tacca, Owen N. Beck, Paolo Taboga, Alena M. Grabowski

“…We calculated standing and running BioL and ProsL lengths and assessed the running-to-standing leg length ratio (Lratio) at three instances during ground contact: touchdown, mid-stance, and take-off. Athletes with UTTA had 2.4 cm longer standing ProsL than BioL length (p = 0.030), but their ProsL length were up to 3.3 cm shorter at touchdown and 4.1 cm shorter at mid-stance than BioL, at 3–11.5 m/s. …”
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Evaluation and mitigation of modelling errors in numerical simulations of mooring line and seabed contact by Low, Chee Meng

“…Specifically, the modelling of line touchdown-liftoff effects requires a finer mooring line discretisation at the touchdown point to avoid the production of spurious line tension fluctuations. …”
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Fatigue analysis of steel catenary riser by Chew, Jia Han.

“…The riser system, which is made of steel, has to withstand hostile condition of the deep sea especially in the touchdown zone. An object which is under constant cyclic loading can fail by fatigue, thus, a fatigue analysis will be done to find out the fatigue life of the SCR at the touchdown zone.…”
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‘Whip from the hip’: thigh angular motion, ground contact mechanics, and running speed by Kenneth P. Clark, Christopher R. Meng, David J. Stearne

“…During high-speed running, lower limb vertical velocity at touchdown has been cited as a critical factor needed to generate large vertical forces. …”
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Analysis of Vibration Attenuation and Energy Consumption of Blasting Demolition Chimney: A Case Study by Shuren Wang, Jiyun Zhang, Jingtao Li, Fuli Kong, Junqi Fan

“…However, the blasting vibration and the touchdown vibration of the parts of the chimney falling to the ground will cause noise disturbance to the local residents. …”
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Posture alteration as a measure to accommodate uneven ground in able-bodied gait. by Soran Aminiaghdam, Reinhard Blickhan, Roy Muller, Christian Rode

“…Two-way repeated measures ANOVAs revealed step-specific effects of posture on the kinematic behavior of gait mostly at toe-off of the pre-perturbation step and the step-down as well as at touchdown of the step-up. In preparation to step-down, with increasing trunk flexion the discrepancy in hip-center of pressure distance, i.e. effective leg length, (shorter at toe-off versus touchdown), compared with level steps increased largely due to a greater knee flexion at toe-off. …”
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Comparative Analysis of the Diagonal Stride Technique during Roller Skiing and On-Snow Skiing in Youth Cross-Country Skiers by Mujia Ma, Shuang Zhao, Ting Long, Qingquan Song, Hans-Christer Holmberg, Hui Liu

“…The hip movement, knee flexion, and calf anteversion at ski/roller ski touchdown and take-off, pole inclination at pole touchdown, body anteversion angle, and trunk anteversion angle at pole touchdown were the points that required caution when transferring preseason practice roller skiing to on-snow skiing.…”
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Impacts of Flight Operations on the Risk of Runway Excursions by Feiyin Wang, Jintong Yuan, Xiaochen Liu, Pengtao Wang, Mao Xu, Xiaoyu Li, Hang Li

“…A total of 2087 flights were classified on the basis of touchdown distance, taxiing distance, and magnetic heading changes and were divided into three styles based on these indicators. …”
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Bumblebees land remarkably well in red–blue greenhouse LED light conditions by Lana J. de Vries, Frank van Langevelde, Coby van Dooremalen, Ilse G. Kornegoor, Martin J. Lankheet, Johan L. van Leeuwen, Marc Naguib, Florian T. Muijres

“…In both conditions, the landing approaches were interspersed by one or several hover phases, followed by leg extension and touchdown. The time between leg extension and touchdown was 25% (0.05 s) longer in red–blue light than in white light, caused by a more tortuous flight path in red–blue light. …”
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Some measures of aircraft performance on the airport surface by Swedish, William J.

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Study of impact and transient vibration of aircraft landing gear by Hong, Weiling.

“…Results showed that height and weight during touchdown affect landing gear performance. Working in accordance to Joint Aviation Requirements (JAR) regulations, the increase in number of throttle valves connected in series circuit would improve the damping effect. …”
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Precise automated landing of a fixed-wing aircraft onto a moving platform by Parker Mohamed Zahier, Engelbrecht Jacobus Adriaan Albertus

“…A prediction algorithm calculates the touchdown point between the aircraft and the moving platform. …”
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Landing stability analysis for lunar landers using computer simulation experiments by Yuanyuan Liu, Shunguang Song, Ming Li, Chunjie Wang

“…In the overall design and performance prediction of spacecrafts intended to accomplish soft landing on the moon, touchdown dynamics analysis during the landing phase is one of the most important tasks. …”
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Optimization of Airplane Landing in Crosswind Conditions for Minimum Tire Wear by Stefano Cacciola, Carlo E. D. Riboldi, Edoardo Generali

“…A notable concern associated with touchdown events, especially when crosswind is present, is tire wear. …”
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PSO Optimized Active Disturbance Rejection Control for Aircraft Anti-Skid Braking System by Fengrui Xu, Mengqiao Chen, Xuelin Liang, Wensheng Liu

“…A high-quality and secure touchdown run for an aircraft is essential for economic, operational, and strategic reasons. …”
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Development of Vertiport Capacity Envelopes and Analysis of Their Sensitivity to Topological and Operational Factors by Vascik, Parker D., Hansman, R. John

“…The approach is used to determine the sensitivity of vertiport capacity to the number and layout of touchdown and liftoff pads, taxiways, gates, and parking pads (i.e. the vertiport topology). …”
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Human-automation task allocation in lunar landing: simulation and experiments by Wen, Hui Ying

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Semi-Active Control for a Helicopter with Multiple Landing Gears Equipped with Magnetorheological Dampers by Quoc Viet Luong, Dae-Sung Jang, Jai-Hyuk Hwang

“…Typically, a helicopter landing gear system with skids or passive wheel-dampers is designed based on only one critical touchdown condition. Thus, this helicopter landing gear system may not perform well in different landing conditions. …”
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Helicopter Landing Trajectory Optimization after Tail Rotor Control Failure in Different Collective Pitch

“…A normal landing maneuver will cause a high yaw rate at touchdown, which is dangerous. Therefore, autorotation is preferred during touchdown because the landing is more secure with small yaw rate. …”
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Impact of visual guidance error on automatic carrier landing performance by ZHEN Chong, QU Xiaolei, WANG Yifeng, ZHANG Yuxiang, HAN Fengming

“…Considering F/A-18A carrier-based aircraft automatic landing task，the simulated positioning measurement accuracy of airborne visual guidance from gliding to touchdown are estimated. The disturbances of automatic carrier landing system delay，airborne sensor noises，air-wake and deck motion are introduced，the multi-factor coupled simulation system is modeled，and the touchdown position standard errors are calculated based on Monte-Carlo simulations influenced by the disturbances. …”
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