khorton
New Member
Are the various Dynon products designed and tested to RTCA DO-160 requirements?
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DO-160 Qualification?
- Thread starter khorton
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- Mar 23, 2005
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Basic answer, no.
We do look at many of the requirements and we are designed to meet them, but we have no certification. These products are made for the homebuilt market, where none of these certifications are required.
We do look at many of the requirements and we are designed to meet them, but we have no certification. These products are made for the homebuilt market, where none of these certifications are required.
khorton
New Member
I agree, that there is no regulatory requirement to meet the DO-160 requirements. But, they do provide a good set of criteria to help ensure that a product will work properly and survive when installed in an aircraft. The EFIS doesn't know whether it is installed in a type-certificated aircraft or not. It makes sense to meet all relevant DO-160 requirements. There is no need for official qualification testing, but it makes sense to do equivalent testing in-house.
Looking at the D-10A specs in the back of the Installation Manual, I see that you do provide much of the info I was looking for. There are a few loose ends however:
Voltage transients - you list 30v DC as the max voltage. Is this the max allowable sustained voltage, or is 30v only a transient limit? What are the allowable transient voltages and the allowable durations at each voltage? For a 14v system, DO-160 calls for a 40v transient for 100 milliseconds. It also calls for a low energy 300v spike delivered through a 50 ohm source impedance. Would the D-10A be harmed by either of these events?
Looking at the D-10A specs in the back of the Installation Manual, I see that you do provide much of the info I was looking for. There are a few loose ends however:
Voltage transients - you list 30v DC as the max voltage. Is this the max allowable sustained voltage, or is 30v only a transient limit? What are the allowable transient voltages and the allowable durations at each voltage? For a 14v system, DO-160 calls for a 40v transient for 100 milliseconds. It also calls for a low energy 300v spike delivered through a 50 ohm source impedance. Would the D-10A be harmed by either of these events?
Canadian_JOY
New Member
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- Jun 26, 2006
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Keith,
I suspect everybody at Dynon is running full throttle this week because of Sun n Fun, so we might not get a long explanation in response to your question. I'll try to shed a little light on Do160 testing in hopes you will come to an understanding...
Testing to Do160 requires a fair amount of equipment, lots of time, and dedicated hardware. The end result of these requirements is that many manufacturers just don't have the necessary 'stuff' to do the full gamut of Do160 testing. That's meant a complete industry based on standards-based testing has arisen. This industry is profit-based. So if you don't have the requisite equipment or skills to do the testing yourself, you can pay to get it done. But it costs a lot. As an example, the last time I did lightning testing on an antenna the tests cost $150K. And then the sustained g-load testing (using a really neat whirl rig driven by a chevy 454 engine...) cost another pile of cash on top of that. And then the salt fog test cost some more. And then...
And Dynon's not going to spend the money. Instead they do their best to design the box to meet the environmental requirements they know their boxes will encounter in real life, and then do the best testing they can to see how close they come to meeting those requirements, and after that it's our risk as to whether the units will survive in our airplanes or not. That's what makes these boxes so cheap. By not having to meet Do160 or TSO requirements the manufacturer isn't making any guarantees of how well the equipment will work. And as soon as you remove the need to make a guarantee you don't have to build a liability contingent into your pricing. That liability contingent can often be half the cost of the unit, so how'd you like to have Do160 compliance in your EFIS, but have the base price set at $5K? In the homebuilt world the economics just don't support Do160 environmental or Do178 software testing.
I'm not defending Dynon or any other manufacturer here, but rather am trying to lay out the decision-making roadmap they've followed in order to bring a product to market at a reasonable price. I'd love to have a fully qualified box in my airplane but would never want to pay for the qualification testing. To that end, I'm glad Dynon's made the choices they have, otherwise I'd have steam gauges instead of EFIS.
If you're really worried about the power input on your Dynon, why not put in place any one of the off-the-shelf power filter modules that are available as pre-filters for commercial dc-dc power supplies? Most of these are pretty good at taming the spikes, transients and EMI/RFI. But they also sell for $200-400 each.
I suspect everybody at Dynon is running full throttle this week because of Sun n Fun, so we might not get a long explanation in response to your question. I'll try to shed a little light on Do160 testing in hopes you will come to an understanding...
Testing to Do160 requires a fair amount of equipment, lots of time, and dedicated hardware. The end result of these requirements is that many manufacturers just don't have the necessary 'stuff' to do the full gamut of Do160 testing. That's meant a complete industry based on standards-based testing has arisen. This industry is profit-based. So if you don't have the requisite equipment or skills to do the testing yourself, you can pay to get it done. But it costs a lot. As an example, the last time I did lightning testing on an antenna the tests cost $150K. And then the sustained g-load testing (using a really neat whirl rig driven by a chevy 454 engine...) cost another pile of cash on top of that. And then the salt fog test cost some more. And then...
And Dynon's not going to spend the money. Instead they do their best to design the box to meet the environmental requirements they know their boxes will encounter in real life, and then do the best testing they can to see how close they come to meeting those requirements, and after that it's our risk as to whether the units will survive in our airplanes or not. That's what makes these boxes so cheap. By not having to meet Do160 or TSO requirements the manufacturer isn't making any guarantees of how well the equipment will work. And as soon as you remove the need to make a guarantee you don't have to build a liability contingent into your pricing. That liability contingent can often be half the cost of the unit, so how'd you like to have Do160 compliance in your EFIS, but have the base price set at $5K? In the homebuilt world the economics just don't support Do160 environmental or Do178 software testing.
I'm not defending Dynon or any other manufacturer here, but rather am trying to lay out the decision-making roadmap they've followed in order to bring a product to market at a reasonable price. I'd love to have a fully qualified box in my airplane but would never want to pay for the qualification testing. To that end, I'm glad Dynon's made the choices they have, otherwise I'd have steam gauges instead of EFIS.
If you're really worried about the power input on your Dynon, why not put in place any one of the off-the-shelf power filter modules that are available as pre-filters for commercial dc-dc power supplies? Most of these are pretty good at taming the spikes, transients and EMI/RFI. But they also sell for $200-400 each.
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- Mar 23, 2005
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30V is a sustained voltage. We work fine in 28 V airplanes.
We meet the DO-160 specs for 28V airplanes. This means we survive 60V spikes no problem. I do not know of a requirement for 300V through 50 ohms. The specs we have and meet require a lower voltage through 50 ohms. There are different levels of DO-160, and this may be the discrepency.
As I say, we meet and test to some of them, others less so. The voltage input one is one that I know for sure we meet. We did a LOT of work on the power supply when we designed it, with DO-160 in mind.
As far as we know, no Dynon product has ever been damaged by a voltage spike in an airplane.
We meet the DO-160 specs for 28V airplanes. This means we survive 60V spikes no problem. I do not know of a requirement for 300V through 50 ohms. The specs we have and meet require a lower voltage through 50 ohms. There are different levels of DO-160, and this may be the discrepency.
As I say, we meet and test to some of them, others less so. The voltage input one is one that I know for sure we meet. We did a LOT of work on the power supply when we designed it, with DO-160 in mind.
As far as we know, no Dynon product has ever been damaged by a voltage spike in an airplane.
khorton
New Member
This is good info. Thanks. Why not make a statement along the lines of "We have not subjected our products to full RTCA DO-160 testing due to the high cost. However, we have designed all our products to meet all the power supply requirements of DO-160X [where X is the correct value for whatever version of the spec you have used], and have done in-house testing to show compliance to these requirements." You could then list a summary of the various DO-160 power supply requirements. This would help illustrate the efforts you have made to deliver a product that will survive and work properly in an aircraft.As I say, we meet and test to some of them, others less so. The voltage input one is one that I know for sure we meet. We did a LOT of work on the power supply when we designed it, with DO-160 in mind.
Or, is there something in DO-160 that prevents it from being mentioned, unless full compliance has been shown with official tests? If so, you could list the details of the requirements you have met, without mentioning DO-160.
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I think today the best statement we can make is that we've shipped 5000+ units with an extremely high reliability record. We feel that that speaks volumes.
Honestly, this issue hasn't come up before, so we've not put the energy into coming up with a statement.
Honestly, this issue hasn't come up before, so we've not put the energy into coming up with a statement.