The new flight-drift model (FDM) of selfconsistent electron transport and electrical charge storage in wide-gap insulators reflects a more realistic simulation of these processes in dielectric and insulating materials than the former mainly ballistic model. Thus, electron-hole creation, their ballistic flight, followed by field-drift transport, and finally trapping in localized states and/or recombination are taken into account. The experimentally accessable quantities of field assisted secondary electron emission σ as well as the resulting surface potential V0 due to internal current j(x,t), charge ρ(x,t), field F(x,t), and potential V(x,t) distributions are obtained. The calculations are performed for bulk Al2O3 ceramics with open and metal-coated and grounded surfaces.