Quick Access Recorder (QAR) Data Analysis Software for Windshear and Turbulence Studies

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 Recorder (QAR) data are obtained from the local airlines by the Hong Kong Observatory (HKO). Instead of using directly the wind data recorded on the aircraft by the flight management system (FMS), there has been a collaborative study between HKO and the National Aerospace Laboratory (NLR) in The Netherlands to develop a QAR data analysis software to calculate the meteorological quantities, such as the three components of the wind, windshear hazard factor and turbulence intensity parameters, taking into account the aircraft’s aerodynamic factors (e.g. sideslip angle, angle-of-attack). This paper describes the main features of the calculation software, named WINDSTURB, and illustrates its application to windshear and turbulence studies through selected cases at HKIA. Nomenclature a0 – a3 calibration coefficients Y side/lateral force Ay lateral acceleration α angle of attack cy force coeffi cient of Y-force β sideslip angle D drag true track angle DME Distance Measuring Equipment F fl ap angle EPR Engine Pressure Ratio ε1/3 eddy dissipation rate (EDR) FMS Flight Management System (non-dim.) vorticity GS groundspeed bias in accelerometer, co-state vector ILS Instrument Landing System w standard deviation of vertical wind variations LIDAR Light Intensifying Detection And Ranging time lag m aircraft mass ω1, ω2 cut-off frequencies in the calculation of EDR