Graybeard, from the report
Air France Airbus A330 aircraft are equipped with the Collins WXR700X radar. The radar image is presented on the NDs superimposed on the other information. It can detect precipitations in liquid form greater than 1 mm/h as well as wet hail. Thus, cloud systems made up of drops of water starting from a certain size can be observed but the radar cannot detect dry particles of ice, hail or snow with a diameter less than three centimetres.
In use, the radar beam has a narrow aperture angle of 3.4°, which means that it is necessary to adjust the TILT (angle between the horizontal and the middle of the beam) accurately, in particular according to the maximum range selected at the ND (RANGE): 160 NM for look ahead, 80 NM for avoidance.
The GAIN adjustment (amplification of the return signal) is normally "calibrated" (in the CAL position) to prevent saturation. However, a manual selection can be made.
A turbulence detection function (for the zones of precipitations in liquid form) is available (in the WX+T or TURB position) in a radius of 40 NM, whatever the RANGE chosen at the ND.
When cruising above 20,000 ft, a slightly downwards adjustment of the TILT is recommended so that the ground echoes only appear on the ND at the limits of the furthest range markers.