RTCA DO-160

[Voodoo13]

Hello,

I'm starting to be interested in the DO-160 of avionic equipment.
I would like to know if there is something, a document for exemple which define the proper Category depending of the criticality of the Equipment (Major/Hazardous...). In particular for section from 17 to 23...
If not, How can I defined if the equipment is properly qualified other than to say that the equipment is already installed on other aircraft ?

The idea is to to write next to each category saying that the equipment is properly qualified for XX reason.

It's a really wide question but hopefully you guys will be able to help me
Thank you very much

 

[Sparweb]

There are specific answers to your questions in the various AC's published by the FAA related to equipment testing and system reliability.

https://www.faa.gov/aircraft/air_cert/design_approvals/transport/rules_acs_policy/

Scroll down to "25.1309".
Study any of the links referenced there that might apply to the equipment you want.
This one is more general:
AC 25.1309-1

Also you should seek the ARP's published by the SAE for system reliability. I believe they are referenced in AC 25.1309-1.

There is a 2-week short course at Kansas University on this subject, too. Valuable info, and it gives you a lot of credibility when talking to regulatory officials to say you have taken such courses.

http://www.sparweb.ca

 

[Voodoo13]

Well thanks you very much but unfortunately i've already been in these Advisory circular and associated documents and there is none notion of the RTCA equipment category linked to the classification (Major/Minor/Catastrophic...).

 

[RoarkS]

Voodoo13,

I just spent the past 2 months in an EMI chamber for a customer. and probably another month or two bookending that doing environmental, shock and vibe and such. Over the past decade I've done this party about once a year for various projects.

Let's say I have a user level experience.

Really big customers have a team that selects what tests various systems will be subjected to then feeds that down to engineering. The people actually designing the equipment usually are told what test to design for. I like to imagine that the initial team are not actually engineers but contract people, who just copy paste from previous contracts... and after they do that a few times with little push back, you end up having to test a Galley convection oven to spacecraft standards, that is stored in a wet hot jungle, on a salty ocean coast, at 30k ft at -60°c/f... oh and fungus and NBC. Most of the time I have a compliance matrix, send that to a testing facility, get a quote... add a % to pay for my time and then some and pass it back to the customer and you will be surprised how quickly Fungus, NBC, the ridiculously long salt fog, acidic atmosphere, testing to space altitudes, and long duration solar exposure go out the window. It takes a few rounds of that and you're quote goes from over $100k down to about $30k is when they will say just run the test. It definitely feels like their approach to risk mitigation is if something happens and the question is asked "Did you test to..." they cut them off and say "YES."

Mid size customers, will actually have their engineering teams sit down and go through the standards with knowledge. Most of them, if you have a good understanding of the EUT, its installation, and its interaction with other aircraft systems you can reasonably figure out which test is applicable to you. Like if you look at section 21.2 Cat P that's what I was playing with. Also the EUT was to be installed close to the CVR/FDR... which sent us down another rabbit hole but turns out those are shielded pretty good. In the case of power input... what situations are likely to happen in your aircraft? You have a 24VDC system, run of an alternator... okay when a diode goes bad how does your PCB react when it starts to see a dirty sine wave... That's 18.2.1 Cat B. That one is especially fun for electronics designed to work off nice clean DC power... WEIRD things start to happen. Oh you have optoisolators you say... doesn't matter. Again comes down to knowledge of the specific system and it's installation, read the spec and the user guide at the end of each section.

Small customers... will build the experimental plane, install everything turn it on, and address problems as they arise instead of making up crap to spend money on.

I will say... DO160 tests and it's little nuances are definitely designed to find the weak points. A lot of those weaknesses may not be "real". Personally I like the small customer approach, because when they find an issue, we find a DO160 test to put the unit up to and it finds it.

Hope that helps.

 

[IRstuff]

Can you give a context, or a specific passage related to your question?

Your second question below is answered by "Qualified by similarity," which is typically acceptable if the host environment of the previous equipment is sufficiently similar that one can claim that the new installation does not introduce any additional stresses or conditions beyond what was qualified for a previous installation.

If not, How can I defined if the equipment is properly qualified other than to say that the equipment is already installed on other aircraft ?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Voodoo13]

Thank you very much Roarks, it's really interested to see the different approach depending of the size of the customer !!

@IRstuff, I'm working in a Part 21J in charge of the certification of Avionic Equipment !! Usually, a lot of Design Approval Organization (DAO) working on Rotorcraft and aircraft are just saying " well,my equipment is TSO and qualified DO-160 so it's all good i can install it safely" without taking consideration such has for exemple vibration, some equipment are qualified for aircraft vibration but not Rotorcraft, some equipment require a distance to Compass to avoid deviation etc... so taking into account the existing rotorcraft or aircraft environnement and compare it to the qualification of the installed equipment is from my point of view really important. I think that the probability that my equipment (already installed in other aircraft/rotorcraft) is not compatible with the environment is very low but i feel more comfortable to justify myself to the authorities that i've donne a small study and everything is ok with the qualification and the environment of the rotorcraft or aircraft.

Also the DO-160 helps me to answer CS 27/29 §1316, saying that my equipment is properly qualified DO-160 section 22 XXXXX for Aircraft Electrical and Electronic System Lightning Protection. But the probleme is that i do not have enough background on the DO-160 to have a critical approach. The idea is that i don't want to says "yes my equipment is qualified D0-160 Section 22 it perfect" without understanding the qualification.

An exemple (for vibration) of what i'm trying to reach :

Equipment:
Qualified D0-160G Section 8 for Robust Vibration Test (Categories R, U, U2)
Compliant ?:
As per Qualification above the equipement is properly qualified for an installation in rotorcraft.

Thank you all

 

[WKTaylor]

Might find the following useful...

AC21-16 RTCA DOCUMENT DO-160 VERSIONS D, E, F, AND G, “ENVIRONMENTAL CONDITIONS AND TEST PROCEDURES FOR AIRBORNE EQUIPMENT”
RTCA DO-357 USER GUIDE SUPPLEMENT TO DO-160G

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[Voodoo13]

Thank you @WKTaylor, I already know the AC 21-16 which summarize the change from DO-160 C to G.
Unfortunately I do not have the DO-357...

 

[WKTaylor]

V13... best I can do for You...

RTCA DO-357
TABLE OF CONTENTS
Purpose and Applicability………………………………………………………………………………….1
User Guide for Section 4 - Temperature & Altitude……………………………………………………….3
User Guide for Section 5 - Temperature Variation………………………………………………………..13
User Guide for Section 7 - Operational Shocks and Crash Safety……………………………………......21
User Guide for Section 8 - Vibration……………………………………………………………………...29
User Guide for Section 9 - Explosion Proofness………………………………………………………….45
User Guide for Section 10 - Waterproofness……………………………………………………………..53
User Guide for Section 11 - Fluids Susceptibility………………………………………………………..59
User Guide for Section 15 - Magnetic Effect……………………………………………………………..65
User Guide for Section 16 - Power Input…………………………………………………………………75
User Guide for Section 17 - Voltage Spike……………………………………………………………….87
User Guide for Section 18 - Audio Frequency Conducted Susceptibility – Power Inputs……………….95
User Guide for Section 20 - Radio Frequency Susceptibility……………………………………………103
User Guide for Section 21 - Emission of Radio Frequency Energy……………………………………..153
User Guide for Section 22 - Lightning Induced Transient Susceptibility……………………………….163
User Guide for Section 23 - Lightning Direct Effects…………………………………………………...193
User Guide for Section 26 – Fire, Flammability………………………………………………………...225
Appendix A Membership………………………………………………………………………………..241

ALSO...

https://www.rtca.org/training/do-160g-training/

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]