Quote:
Originally Posted by Claycron
Have you ever seen or heard any stories about St. Elmos Fire? If so do the static impulses have any affect over your planes radio communications? How rare of an occurrence is it?
I've seen St. Elmo's fire many times, probably at least once a year. It seemed to be much more common in the turboprops, but that may just be because we spent more time in the weather down low (in the 16000-20000' range). Flying through snow showers seems to be good conditions for this phenomenon.
In the prop planes, you could sometimes see the entire circumference of the props glowing a purplish-blue color. The most common display of St. Elmo's Fire is an appearance of spider-web blue streaks coursing up the windshields. It looks very much like those novelty devices you may have seen where you can touch a 10 inch diameter (approx.) glass globe and watch the blue "lightening" attracted to your touch. (Is this description making sense to anyone?)
St. Elmo's Fire is harmless and usually doesn't affect radio communications. But I have had a few instances (again when flying through snow), where a static build-up on the plane started causing static over the radios.
In one of the most dramatic instances I recall, I was in an MD-88 on downwind to Runway 01 at DCA, flying through snow. The radio static got so bad we couldn't communicate at all (no St. Elmo's fire during this time) and finally there was a bright (very bright) discharge just forward and left of the nose with a loud (very loud) bang. The radios were then crystal clear and we proceeded to land without incident. This was such an abnormal occurrence, however, that we checked with the FAs and were told that they had observed the bright flash and heard the bang. So, I made a PA to the passengers (even though we were down low...we don't normally make PAs below 10,000') to reassure them.
A static build-up like this is unusual because all large planes have static discharge wicks on the trailing edges of the wings. Take a look sometime at the back edge of the ailerons and wing-tips and you'll see metallic wicks about 6-12" long. Their sole purpose is to dissipate the static build-up which naturally occurs from the friction of air passing over the wing.