Static Discharge (sometimes referred to as St. Elmo’s fire (огни святого Эльма) is a visible luminous electrical discharge observed around parts of an aircraft when the electrical charge on the aircraft becomes sufficiently intense.
It occurs when the atmosphere becomes charged and an electrical potential strong enough to cause a discharge (plasma), which is created between an object and the air around it.
While not a hazard in itself, it is an indication of Thunderstorm activity and may be a precursor (предвестник) to a Lightning strike.
It can sometimes be heard "singing" on the aircraft's radio, a frying or hissing sound running up and down the musical scale.
