The data collection consists of the airborne measurements obtained in the framework of the AWI-campaign "SpringTime Atmospheric Boundary Layer Experiment" (STABLE) that are used as supplement for the study by Michaelis et al. (2020). The measurements were performed in the atmospheric boundary layer near three different leads in the Arctic Marginal Sea Ice Zone north and northwest of Svalbard on 10, 25 and 26 March 2013. All cases represent conditions of a nearly lead-perpendicular convective flow over the leads.This data set contains the cross-lead flight data: a low-level horizontal flight leg performed across the lead along the mean wind direction.