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Whenever a design company is obtaining an STC for an aircraft (Supplemental Design Certificate) for an electrical installation, one of the required tests to obtain the STC is a lightning strike test. The test is needed to show that the electronics installed can withstand a lightning strike without degrading their performance or inducing degradations into other systems.

We can't position the aircraft on ground waiting for a lightning bolt to hit like 'Doc' in 'Back to the Future', so how do design companies, or engine manufacturers, etc. simulate a lightning strike and draw conclusive results that the system with withstand actual lightning?

TomMcW
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esé
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    If you can find some local Tesla coil enthusiasts around your area that will generally be more than happy to fire off the type of voltage/current combinations at whatever you'll let them. Could even sit inside it like in the image below since it's basically acting as a Faraday cage anyway. – Chris W. May 13 '14 at 19:17

2 Answers2

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You create your own lightning. You can do that with an impulse generator. Here's what a smaller one looks like:

impulse generator

I don't know if that's what is used for the certificates but it certainly one way to test against lightning strikes (provided that you can generate a high enough voltage).

mmaag
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    I am not positive but I think only the aircraft manufacturer uses very high voltage (enough to damage the aircraft) only on the Type Certificate. Whereas other lightning strike tests use lower non-damaging tests, then by measuring the resulting currents one can mathematically simulate the full voltage by simply multiplying the measurements accordingly. I only heard this from word of mouth though from an engineer at Rolls Royce. – esé May 12 '14 at 04:31
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So, Lightning Strike Test - Panthera Aircraft by Pipistrel - Episode 1 is a short video showing how Pipistrel did it. I really want to be able to push that button! :)

This page is a video and article showing how NASA does it.

Here is a Scientific American article about the why's more than the how's.

CGCampbell
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    The videos both show testing just a separate bits of skin, while the electronics needs to be tested with the complete airframe. – Jan Hudec May 11 '14 at 11:35
  • +1 for interesting info on skin tests but as Jan mentioned I am thinking more in terms of installation onto an airframe where the lightning strikes the frames. – esé May 11 '14 at 12:22
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    @esé there are facilities that can hold a small plane and fire lightning at it – ratchet freak May 11 '14 at 15:53
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    Please add more than just links to your answer. Quoting the help center's How do I write a good answer?: "Always quote the most relevant part of an important link, in case the target site is unreachable or goes permanently offline." In this case, include a brief summary or quote describing each method. – Bret Copeland May 12 '14 at 01:38