A laboratory study of aircraft precipitation static charging

Laboratory experiments show that when small ice particles collide with targets at speeds of up to 80m/s then the charge transfer is dependent upon the work function of the target material. Most common materials charge negatively, in agreement with observed aircraft charging in ice clouds, but magnesium which has a low work function charges positively. These results enable the charging of materials to be predicted before flight, and also suggest that alloys of magnesium should minimize aircraft charging. The laboratory apparatus could be used to characterize the charging of the new composite materials for aircraft surfaces.