need help, RTCA/DO160 section 23. lightning, direct effect

[dho]

we have a tube shaped valve made of anodized aluminum. we got the following test requirements. i am not familiar with the lightning direct effect test. how it is done. does the requirement make sense, DO160E has only components A, B, C, D. no waveform A,B,C,D. at 400A and 40A, how to meet the coulomb numbers specified in DO160E in the time period specified ? and more questions....
thanks a lot.

the complete requirements -
The valves shall be able to conduct a 400 A Waveform B (as per RTCA/DO160, Section 23) lightning transient in a safe manner that causes no catastrophic or hazardous effect to the aircraft.
The valves shall be able to conduct a 40A Waveform C (as per RTCA/DO160, Section 23) lightning transient in a safe manner that causes no catastrophic or hazardous effect to the aircraft.

 

[Skier11]

Lightning testing requires rather extensive test equipment,instrumentation and expertise. Many OEM's and most lower tier manufacturers utilize an outside laboratory. Lightning Technologies Inc is one popular lab in the Untied States. There may be more choices for the relatively low levels quoted, as opposed to a full 200 Kamp direct strike.

It may also make a difference as to what type of valve and what is the hazard being protected against (loss of function, inadventent actuation, fire or explosion, etc.)

 

[DHambley]

Your valve is most likely part of a larger system for which the equipment or aircraft manufacturer should have already specified the test scenario. You will see phrasing in DO160 like, "install the test item to ensure its configuration is representative at that used in actual service". The interfaces to your tube should be defined so that you know if its part of secondary structures that are flight critical or not. They should already know suspected lightning attachment points, etc. The lightning path, from the attachment point through the skin to the interface of your tube to whatever will be part of this test set-up. The engineers at EMI test labs are very well versed in all sorts of scenarios for lightning tests - they're the people you should consult for your test set up, as well as the aircraft manufacturer.


Darrell Hambley P.E.
SENTEK Engineering, LLC