Estimation of Accuracy of Temperature and Wind Measurements in theAMDAR System Using the Yak-42D “Roshydromet” Research Aircraft Data

The paper presents the results of the comparative analysis of the AMDAR measuring system aboard regular airliners and the measuring system of the Yak-42D “Roshydromet” new-generation research aircraft. It is shown that root-mean-square errors of air temperature, wind speed, and wind angle measurements based on the data of the research aircraft for the conditions of horizontal steady flight are 0.3°C, 0.7 m/s, and 0.5°, respectively. These values characterize the ultimate accuracy for the modern aircraft instrumentation. Based on flight tests and computer simulations, the possible sources of errors in the AMDAR system are analyzed: aircraft maneuvers, variations in the air flow over fuselage, and the application of simplified formulas for calculations. It is demonstrated that the errors in the wind speed and wind angle determination in the AMDAR system under aircraft maneuvers with air flow deflection can reach 5 m/s and 30°, respectively. It is proposed to exclude from consideration the AMDAR data obtained during the maneuvers of airliners with roll angles above 10° and to suppose that the error of the AMDAR system in a flight without any roll and turning is 1°C for air temperature, 3 m/s for wind speed, and 5° for wind angle.