Engine-driven charging of helicopters

Charging of aircrafts can lead to breakdown and, as a result, to generation of radio interference in various frequency ranges. The problem of aircraft charging has recently become especially significant due to extensive application of polymer and composite materials in the aircraft industry due to their low electric conductivity and, therefore, allowing to avoid complete metallization of vehicle boards. The UNU KKGS team studied the processes of in-flight helicopter charging experimentally for the first time. Specially developed original d.c. field sensors were used to measure intensity of the static electric field, which is produced by charges on the helicopter body, on the ground. It was found that the helicopter body is charged positively, while the exhaust gases carry the negative charge out, i.e., the engine operation is the reason of charging. The proposed model of charging implies that soot particles are charged in the weakly ionized plasma in the combustion chamber of the gas-turbine engine and then carried out in a jet of exhaust gases. This research was funded under an RF government grant No. 14.B25.31.0023.

Original electric sensor used in field measurements
Distribution of the vertical component of the electric field produced by a helicopter as a result of its in-flight charging

Varfolomeev A.A., Gushchin M.E., Korobkov S.V., Kostrov A.V., Palochkin Yu.P., Priver S.E., Odzerikho D.A., and Strikovskii A.V. Engine-driven electrization of aircraft as a radio interference source // Technical Physics Letters, 2015, V. 41, No. 1, P. 14–17.