This technical report provides information on validation activities of ICESat-2 sea ice products in April 2019 by airborne observations within the IceBird aircraft campaign series of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research. The airborne data acquisition includes direct observations of snow freeboard, snow depth on sea ice and sea-ice thickness by a set of sensors. The following sections specify the extent of airborne data collocated with an ICESat-2 orbit, the specification of the sensors and the file format of the validation data.