# How is an on ground lightning strike test conducted?

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?

• 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. Commented May 13, 2014 at 19:17

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

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).

• 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
Commented May 12, 2014 at 4:31

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.

• The videos both show testing just a separate bits of skin, while the electronics needs to be tested with the complete airframe. Commented May 11, 2014 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
Commented May 11, 2014 at 12:22
• @esé there are facilities that can hold a small plane and fire lightning at it Commented May 11, 2014 at 15:53
• 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. Commented May 12, 2014 at 1:38