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Lightning Strike / Discharge Incident Questions

dpilot_citation

Well-known member
Joined
Dec 3, 2003
Posts
55
Total Time
4700
I have some questions about a situation which took place a couple of weeks ago. We where in cruse flight at FL 400 and I noticed a line of Saint Elmo’s fire on the copilots front window and continue back to the side window. Then I saw a small blue flash. At the time we where at least 25 miles from any perception but we where in the tops of the clouds. After landing I noticed burn marks on the telephone antenna.



We carefully inspected the aircraft and found no other signs of an electrical discharge. When it was taken to the shop, the mechanics found two static wicks (on top of the tail) which showed signs of heat. They also noted a small discharge on one of the flap rollers and what appeared to be rock chips on the radome . They logged this as a lightning strike and returned the aircraft to service after replacing the telephone antenna (the phone continued to work).



My questions are:


  • Has any one had a similar strike or discharge incident?

  • Could the fact that the owner was on the phone at the time added to the situation?

  • What could we have done different other than stay home?

  • What will the damage history deduct from the price of a 6 mil jet?


Any and all thoughts and comments in helping figure this out and avoiding the situation in the future are greatly appreciated.



Dpilot
 

414Flyer

Down with Chemtrails!
Joined
Jan 20, 2002
Posts
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I was struck last year when flying a Cheyenne over India. Ironically one of our other Cheyennes was hit that same day too. I think we were both hit while flying thru ice crystals from a tstorm anvil.

It entered thru a rack of cloud seeding flares on top of one wing, and exited thur the rack of flares on the other wing, igniting one flare on each side.

No damage, just a small pit on one rack of flares, 2 flares burned..

I dont think it matters any whether someone is using a radio. I have heard some people make similar statements about using handheld radios, and I dont think it matters whether you are on the radio/phone or not. I think that is an urban legend that using the radio makes it easier for lighting to travel to it.

I dont think lightning strike really does anything for damage history, because it is fairly common, I think many aircraft have been hit, usually it does not damage anything, although it can take out little nicks in props, or do a spot weld in an engine.

If you want to guarantee to not be hit, then steer way clear or storms, but even that can not protect you, since if you are downwind of the storm, but flying thru an anvil area of ice crystals like I was, you can still get a cloud to cloud strike on the plane.
 

RockyMnt1

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Joined
Jul 22, 2002
Posts
163
Total Time
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Beech Duke, IMC, no precip within 25 miles. Entered thru the left prop exited thru the right winglet. All static wicks looked normal. A burn mark on the prop and winglets was observed.

A complete tear down of both of the engines was required so that an inspection/magnaflux test could be performed. The concern was that there was high temperature arching between metal parts across the thin oil film that would change the characteristics of the metal. These tests/inspections might be a result of the location of the lightning entry/exit points, not real sure about this.

Avionics (including wx radar)/CBs were not affected at all.

It was the wrong place/wrong time to be at that spot, but I really don't see how it could have been avoided, since it was totally unexpected and there was no evidence that it was about to happen.
 

avbug

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Joined
Dec 14, 2001
Posts
7,602
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I had two occurences like that, once last year, once this year. St. Elmo's appeared across the windscreen, and then around the forward area of the aircraft. Nothing unusual there. In this case, however, it "burst into flames," with the appearance of a campfire going straight up, about twelve feet or so (guestimate). It stayed that way for a short period, and then laid down in front of the aircraft in a flat formation that extended away from the nose of the airplane, some fifteen feet or so. It had the appearance of a waving carpet.

After a few moments, it formed into five distinct poles radiating out from the front of the airplane, and these slowly came together to form one column that appeared to be "shining" out in front of the airplane. It was about a foot and a half in diameter, blue-green in color, and waving, or pulsing irregularly. I was leaning forward in my seat to have a better look, as I'd never seen st. elmo's or corona do that before, when it discharged. A loud bang, much like a baseball bat striking the windscreen, a blinding white flash, and it was gone.

That one occured at night, and I was completely blind. We were approximately 12,000 descending for an approach in some light precip, no reported convective activity, in the winter in a coastal location. We discovered burn marks along the side of the airplane, splayed and blown-out burn marks in the radome typical of a lightening discharge, burn marks on the stall vane and pitot tubes, a hole burned in a control surface, engine damage, control damage, and a number of other things, too.

The second one occured at approximately 10,000' while descending into Las Vegas, with convective activity around. We were just starting a turn for a cell on radar, in the terminal area, and had no prior warning or visual cues. It may have been lightening, or it may have been another discharge or a different sort. I can't say. I grounded the airplane, and discovered burns on the rivets for the elevator hinge points, burned control surfaces, and similiar damage to what occured on the first situation. In each case, I later learned that none of the static wicks had been properly bonded, and when each was removed, a layer of nonconductive paint was found beneath. Several of the wicks had been blown out or melted. We experienced vertical gyro damage with a comparator warning, but no apparent damage to avionics. The autopilot worked, the FMS and EFIS displays worked, both times.

Best of all was the company reaction...it had to be pilot error, they said. Go figure.
 
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