Low-level windshear, which refers to sustained changes of headwind of 15 knots (7.7 m/s) or more over a ... of a radiometer in the alerting of lowlevel windshear. A ground-based, 14-channel microwave radiometer (7 ... significant rainfall. Two approaches to the alerting of windshear have been studied, namely, the calculation of Brunt- ... the boundary layer of the atmosphere (terrain-induced windshear tends to occur in stable boundary layer) and ... with the temperature fluctuations. The performance of the windshear alerting rules so developed is studied by the ...
Tópico(s): Wind and Air Flow Studies
2011 - E. Schweizerbart | Meteorologische Zeitschrift
Terrain-induced windshear at Hong Kong International Airport (HKIA) could be hazardous to the landing and departing aircraft. Such windshear occurring in a planetary boundary layer without temperature ... its capability to forecast the occurrence of such windshear. The model is found to have skills in capturing the terrain-induced windshear, including the terrain-induced microburst due to the mountains of Lantau Island. Moreover, the windshear detection algorithm as applied to the AVM output, ... advance alert for the occurrence of low-level windshear. The model also offers new dataset, such as ...
Tópico(s): Wind and Air Flow Studies
2016 - Hindawi Publishing Corporation | Advances in Meteorology
Feng Chen, Haorong Peng, Pak Wai Chan, Xiaoxiang Ma, Xiaoqing Zeng,
Abstract Low‐level windshear poses serious hazards to the flight safety of civil aircraft. The objective of the study was to assess the risk of windshear occurrence within 1 hr at runway corridors at Hong Kong International Airport (HKIA). Windshear report records from HKIA and weather data around ... rare‐event logistic regression was employed to evaluate windshear risk considering the imbalanced nature of the data. ... the risk of the hourly occurrence of the windshear. Results indicated that at HKIA, March, April, July ...
Tópico(s): Meteorological Phenomena and Simulations
2020 - Wiley | Meteorological Applications
A. Miele, T. Wang, C. Y. Tzeng, W. W. Melvin,
... with optimal flight trajectories in the presence of windshear. The abort landing problem is considered with reference ... upon sensing that the airplane is in a windshear, the pilot increases the power setting at a ... Numerical results are obtained for several combinations of windshear intensities, initial altitudes, and power setting rates. For strong-to-severe windshears, these conclusions are reached: (i) the optimal trajectory ... iii) the peak altitude drop depends on the windshear intensity, the initial altitude, and the power setting ...
Tópico(s): Aerospace Engineering and Control Systems
1987 - Elsevier BV | IFAC Proceedings Volumes
... application of Thrust Vectoring (TV) technology for improving windshear recovery of civil aircraft in microburst windshear encounters. A numerical trajectory optimization technique based on ... to achieve robustness with respect to uncertainness in windshear size and strength. TV aided windshear recovery has also been compared with an alternative approach to improve the windshear survivability capability, namely, the application of lateral maneuvering. ... promise as a useful means to truly improve windshear recovery.
Tópico(s): Gas Dynamics and Kinetic Theory
1999 - Emerald Publishing Limited | Aircraft Engineering and Aerospace Technology
Jinlong Yuan, Lian Su, Haiyun Xia, Yi Li, Ming Zhang, Guangju Zhen, Jianyu Li,
... in landing and departure. A new approach for windshear alerting is proposed and demonstrated. This approach monitors ... location restriction of the single lidar. Finally, a windshear alerting message is generated through quantitatively evaluating the ... monitoring area. The new CDWL-based approach for windshear alerting is implemented at the Beijing Daxing International ... some meteorological phenomena of aviation hazards, including microburst, windshear, gust front, and vortex are well captured. Particularly, ...
Tópico(s): Meteorological Phenomena and Simulations
2022 - Multidisciplinary Digital Publishing Institute | Remote Sensing
A. Miele, T. Wang, W. W. Melvin, Roland L. Bowles,
... guidance strategies for near-optimum performance in a windshear. The takeoff problem is considered with reference to ... presented. This approach needs local information on the windshear and the downdraft. The gamma guidance scheme produces ... almost identical results. Although local information on the windshear and the downdraft will be available in future ... presented which is useful for flight in severe windshears. The simplified gamma guidance scheme yields trajectories that are close to the optimal trajectories in severe windshears; in addition, it is easy to implement as ...
Tópico(s): Aerospace Engineering and Control Systems
1988 - American Institute of Aeronautics and Astronautics | Journal of Guidance Control and Dynamics
Russell Targ, Michael J. Kavaya, R. M. Huffaker, Roland L. Bowles,
... on the critical problem of detecting and avoiding windshear since the crash on 2 Aug. 1985 of ... As part of the NASA/FAA National Integrated Windshear Program, we have defined a measurable windshear hazard index that can be remotely sensed from ... about the line-of-sight component of a windshear threat from his present position to a region ...
Tópico(s): Remote Sensing and LiDAR Applications
1991 - Optica Publishing Group | Applied Optics
Nicolas Seube, R. Moitie, G. Leitmann,
... dynamics during take-off in the presence of windshear. We formulate the take-off problem as a ... second player is the disturbance caused by a windshear. We impose state constraints (called viability constraints) on ... constraints, which guarantee aircraft survival when encountering a windshear with given maximum intensity. By using viability theory, ... domains of an aircraft during take-off within windshears.
Tópico(s): Advanced Control Systems Optimization
2002 - Pergamon Press | Mathematical and Computer Modelling
Chin-Tang Weng, Ching-Shun Ho, C. Edward Lan, Michael Guan,
... that ran off the runway after touchdown during windshear encounter are evaluated based on the data in ... path from the data in the FDR. The windshear guideline is reviewed and compared with the airport weather data. To analyze the windshear effect in more detail, unsteady aerodynamic models for ... a combined crab and sideslip landing in unsteady windshear conditions.
Tópico(s): Vehicle Dynamics and Control Systems
2006 - American Institute of Aeronautics and Astronautics | Journal of Aircraft
Yihua Cao, Yong Chen, Kungang Yuan, Jin Chang-jiang,
... and its application in the flight control during windshear penetration are introduced here. With the employment of a real engineering windshear model and NID, a low‐altitude windshear penetration flight control law is designed. The simulative ... control of the aircraft during the penetration of windshear.
Tópico(s): Adaptive Control of Nonlinear Systems
2004 - Emerald Publishing Limited | Aircraft Engineering and Aerospace Technology
Frédéric Dehais, Mickaël Causse, François Vachon, Nicolas Régis, Eric Menant, Sébastien Tremblay,
... occurred while the pilots dealt with a critical windshear. Results: In the windshear scenario, 11 pilots (39.3%) did not report ... pilots perceived the auditory warning in the no-windshear scenario. Also, of those pilots who were first exposed to the no-windshear scenario and detected the alarm, only three suffered from inattentional deafness in the subsequent windshear scenario. Conclusion: These findings establish inattentional deafness as ...
Tópico(s): Occupational Health and Safety Research
2013 - SAGE Publishing | Human Factors The Journal of the Human Factors and Ergonomics Society
S. M. Tse, Masahiro Hagio, Yuji Maeda,
... Hong Kong International Airport (HKIA) is susceptible to windshear and microbursts caused by convective weather. Due to the complex terrain around the HKIA, windshear caused by strong winds of tropical cyclones across ... TDWR) has been used to detect microbursts and windshear in real time to safeguard aviation safety. The ... Tuen Mun, Hong Kong, was optimized to detect windshear and microbursts in a highly cluttered environment. Stationary ...
Tópico(s): Tropical and Extratropical Cyclones Research
2019 - Wiley | Meteorological Applications
Jinlong Yuan, Haiyun Xia, Tianwen Wei, Lu Wang, Bin Yue, Yunbin Wu,
... instruments. Here, a method for identifying cloud, precipitation, windshear, and turbulence in the ABL using a single ... the spectrum broadening may be due to turbulence, windshear or precipitation, the spectrum skewness is introduced to ... judging from shear intensity and TKEDR, turbulence and windshear are classified. As a double check, the temporal ... such as low-level jets are identified as windshear, while arbitrary wind variances conditions are categorized as ...
Tópico(s): Wind and Air Flow Studies
2020 - Optica Publishing Group | Optics Express
Pak Wai Chan, K. K. Lai, Q.S. Li,
Abstract A case of severe low‐level windshear at the Hong Kong International Airport was investigated in this study using large eddy simulation (LES) with a spatial resolution of 40 m. ... to have skills in capturing the low‐level windshear reports from the pilots. The headwind refers to ... simulation and in the application to low‐level windshear alerting.
Tópico(s): Atmospheric aerosols and clouds
2021 - Wiley | Meteorological Applications
A. Miele, T. Wang, C. Y. Tzeng, W. W. Melvin,
... problem of flight trajectories in the presence of windshear is discussed. The abort landing problem is considered ... vertical plane. It is assumed that, at the windshear onset, the power setting is increased at a ... Numerical results are obtained for several combinations of windshear intensities and initial altitudes. Guidance trajectories are considered, ...
Tópico(s): Spacecraft Dynamics and Control
1989 - Elsevier BV | Journal of the Franklin Institute
A. Miele, T. Wang, W. W. Melvin,
Flight trajectory guidance in the presence of windshear is considered with reference to flight in a vertical plane. Both horizontal shear and the presence of a downdraft are assumed. The optimal ... the angle of attack is determined by the windshear intensity, the absolute path inclination, and the glide ... while the power setting is determined by the windshear intensity and the velocity. Particular attention is given ...
Tópico(s): Computational Fluid Dynamics and Aerodynamics
1989 - American Institute of Aeronautics and Astronautics | Journal of Guidance Control and Dynamics
... of the scheduling of incidence that exactly cancels windshear effects, and of the groundspeed a'nd airspeed ... given for a range of values of the windshear susceptibility parameter, representing aircraft with small or large ... jet fighters and large transports; the cancellation of windshear effects isachievable only if the incidence schedule lies ...
Tópico(s): Geophysics and Gravity Measurements
1989 - Cambridge University Press | The Aeronautical Journal
For analysis of low-level windshear and turbulence events at the Hong Kong International Airport (HKIA), besides pilot reports routinely received from Air Traffic Control, Quick Access ... such as the three components of the wind, windshear hazard factor and turbulence intensity parameters, taking into ... software, named WINDSTURB, and illustrates its application to windshear and turbulence studies through selected cases at HKIA.
Tópico(s): Aerospace and Aviation Technology
2010 - American Institute of Aeronautics and Astronautics | Journal of Aircraft
G. Leitmann, Sandeep Pandey, E.P. Ryan,
Abstract The control of an aircraft encountering windshear after takeoff is treated as a problem of stabilizing the climb rate about a desired value. An adaptive strategy is developed which uses only climb rate information. Robustness vis à vis windshear structure and intensity is illustrated via simulations employing four different windshear models.
Tópico(s): Fluid Dynamics and Turbulent Flows
1993 - Wiley | International Journal of Robust and Nonlinear Control
The hazards posed by low-level windshear are an important issue in commercial aviation. Extensive research into methods for coping with low-level windshear has been continuing for many years. This paper ... aviation, and initiatives undertaken to prevent low-level windshear mishaps today and in the future.
Tópico(s): Risk and Safety Analysis
2005 - Embry–Riddle Aeronautical University | The Journal of Aviation/Aerospace Education and Research
K. K. Hon, Pak Wai Chan, Y. Y. Chiu, Wenbo Tang,
... systems, to provide alerting services of low-level windshear and turbulence for Hong Kong International Airport. For ... and are rapidly changing, such as low altitude windshear and turbulence associated with buildings or man-made ... on the feasibility of strengthening early alerting for windshear and turbulence over the north runway’s eastern ...
Tópico(s): Meteorological Phenomena and Simulations
2014 - Hindawi Publishing Corporation | Advances in Meteorology
Louis Kwan-Shu TSE, Yu Guan, Larry K.B. Li,
During a tropical cyclone, windshear can occur at Hong Kong International Airport (HKIA) owing to interactions between strong winds and the complex topography of the ... southeasterly winds that are the most conducive to windshear. For these two wind directions, we find that windshear is most likely to occur along the glide ... construction, is the least likely to suffer from windshear. By showing how airflow disturbances arise from the ...
Tópico(s): Meteorological Phenomena and Simulations
2019 - Elsevier BV | Computers & Mathematics with Applications
Pak Wai Chan, K. K. Hon, Q.S. Li,
... HKIA) is likely to bring about low‐level windshear and turbulence to the aircraft, which could result ... earlier indication of the occurrence of low‐level windshear for airports with complex terrain. However, some mesoscale ... be captured by the models, and the associated windshear events would be difficult to forecast. This paper ... weather forecasters in the prediction of wind and windshear at airports with similar complex terrain in other ...
Tópico(s): Aerodynamics and Fluid Dynamics Research
2019 - Wiley | Weather
Pak Wai Chan, K. K. Lai, Wai Kong, S. M. Tse,
Abstract Three windshear/microburst detection algorithms are used operationally at the Hong Kong International Airport. Their performance is studied in the ... The performance is evaluated using pilot reports of windshear. It turns out that the glide path scan windshear detection algorithm has the best overall performance by ...
Tópico(s): Precipitation Measurement and Analysis
2023 - Wiley | Atmospheric Science Letters
Low altitude windshear phenomena has been causally linked to numerous civil transport aircraft incidents with fatalities and injuries exceeding 800, covering ... 2,1994 has caused an increased focus on windshear and microburst activity. FAA, NASA, the airline industry ... both wet and dry microbursts indicative of hazardous windshear conditions at longer ranges than the other two. ... the tester concept described herein. The weather and windshear models defined use the identical criteria established for ...
Tópico(s): Computational Fluid Dynamics and Aerodynamics
1995 - Institute of Electrical and Electronics Engineers | IEEE Aerospace and Electronic Systems Magazine
The Doppler Lidar windshear alerting system at the Hong Kong International Airport (HKIA), the first of its kind in the world, has been ... paper reports on an enhancement to the automatic windshear detection algorithm at HKIA, which aims at filtering ... and over 1500 quality-controlled pilot reports of windshear (PIREP). The “gentle ramp removal” (GRR) function is ... the state-of-the-art in operational Lidar windshear detection and can provide useful reference to airports ...
Tópico(s): Atmospheric aerosols and clouds
2021 - Multidisciplinary Digital Publishing Institute | Atmosphere
... is difficult to define precisely what constitutes hazardous windshear. It is even more difficult to evaluate detection ... processor, is flight guidance for recovery from microburst windshear. Ongoing research [46] has as an objective, performance evaluation of various strategies for recovery from windshear encountered during the approach-to-landing, including the ...
Tópico(s): Atmospheric aerosols and clouds
1991 - Elsevier BV | Digital Signal Processing
M. Aznar Fernández-Montesinos, G. Schram, Rob Vingerhoeds, H.B. Verbruggen, J.A. Mulder,
Many aircraft accidents are related to hazardous windshear phenomena, in particular to the microburst. The energy loss which is associated with a microburst encounter can be very dangerous for the aircraft ... is developed based on energy principles, since the windshear is basically an energy problem. Additional energy is ... priority assignment, activated at the encounter of the windshear. This priority is determined with respect to a ...
Tópico(s): Aerospace Engineering and Control Systems
1999 - American Institute of Aeronautics and Astronautics | Journal of Guidance Control and Dynamics
H.-T. Liu, C. Golborne, Y. Bun, Megan C. Bartel,
A prototype surface windshear alert system (SURFWAS), a low-cost and portable version of the Federal Aviation Administration low-level windshear alert system, was successfully developed and tested. The ... to the MS via a uhf radio link. Windshear profiles are derived directly from the measured wind ... the data-analysis module. One of the five windshear states from no windshear to windshear or microburst alert are issued by comparing the maximum windshear to a set of predetermined thresholds related to ...
Tópico(s): Meteorological Phenomena and Simulations
1998 - American Institute of Aeronautics and Astronautics | Journal of Aircraft