Have you heard of St. Elmo’s Fire?
Whether you have or not, here’s why you should learn about this if you have a bucket-list of things you’d like to experience in your future travel agenda.
Travelers always talk about wanting to witness the Northern Lights at least once in their lifetime. But there is an added sight that only a few airline passengers get to see.
When you travel by air you just may be lucky to catch a glimpse of this infrequent sight. From your vantage point, you’d be most likely to see it on the airplane wing!
As a matter of fact, in my more than 31 years of airline-flying as a pilot I have only seen St. Elmo’s Fire once myself!
Unlike the common sight of window static discharge St. Elmo’s Fire is a very rare sight seldom seen by anyone, including pilots.
As a matter of fact, many pilots refer to window static discharge as being St. Elmo’s Fire. That assumption, however, is incorrect.
My personal experience with St. Elmo’s Fire
My personal St. Elmo’s Fire experience occurred above the Bikini Atoll in the Pacific, in 1989. There was strong thunderstorm activity in the area. I was flying a DC-10, on the way to Honolulu.
Suddenly a pointed glow of blueish light appeared on the airplane nose cone. A few seconds later the light intensified and stayed lit like a flame for several minutes.
Then, as quick as it appeared the light disappeared, as the discharge finished its cycle.
Unfortunately, this was long before the invention of cell phones and digital cameras, so none of us three pilots carried a camera at the time, to document our sight.
What is St. Elmo’s Fire?
St. Elmo’s fire is a type of luminous plasma discharge from a pointed object. This electrical discharge is called a corona discharge. It occurs spontaneously and naturally in fields that carry a high voltage.
The phenomenon occasionally occurs when you fly around a highly electrically charged thunderstorm, or in an area around an erupting volcano.
It typically looks like a beam of bright blue light coming out from a pointed object, such as the nose cone of an airplane. The color results from the mainly nitrogen and oxygen which our atmosphere consists of.
As a matter of fact, the entire airframe of your airplane can also be subject to a general glowing discharge from St. Elmo’s fire.
The glow was named after St. Erasmus, who is the patron saint for sailors. The phenomena was not understood at the time, evoking folklore and fear of the unknown among sailors of the time.
The life-cycle of St. Elmo’s Fire
Once the “light show” begins it stays around the object affect until it dissipates. It’s discharged through the airplane static wicks. It typically lasts from a few seconds to minutes.
The light-effect is caused by a difference in voltage between the charged object and the surrounding air.
If the voltage between the two gets up to around 30,000 Volts per centimeter of space, the electrical energy is discharged causing the light effect. Even a hissing sound may be heard when that happens. The reaction literally tears apart air molecules.
Objects that are pointed can discharge at much lower levels of voltage. The airplane wing tip, the nose cone of the airplane, the pointed mast of a building, or the mast of a ship can produce St. Elmo’s Fire.
British Airways Flight 9, Jakarta, Indonesia, 1982
How St. Elmo’s Fire was generated from volcanic ash
St. Elmo’s Fire is a completely harmless natural phenomenon. It is widely known that St. Elmo’s Fire is associated with thunderstorms.
The following incident you are about to see on video did not involve thunderstorms, however. Rather, it was rooted in accidentally flying into dangerous volcanic ash!
The volcanic ash caused a lot of damage to this British Airways Boeing 747.
It’s important to note that the danger to the airplane you see here is not from the harmless St. Elmo’s Fire action but from the volcanic ash!
Regardless, it’s probably the most spectacular St. Elmo’s experience anyone has ever experienced in the air.
British Airways, June 24, 1982. Credit: Smithsonian Channel.
The video clip illustrates the turn of events that led to this near catastrophic accident. This presentation does not illustrate how it ended.
But you can rest assured that the plane landed safely, but with serious damage to the engines, airplane body, and windows. No one on board was hurt.
The pilots did an excellent job, followed emergency procedures, and made perfect decisions leading to a successful conclusion to the incident.
Great progress in volcanic ash avoidance procedures, detection and reporting has been made since 1982. Therefore, an incident like this one is not ever likely to happen again.