Serviceability of glass cockpit systems

[gamefreak32]

I have always wondered about how long these new glass cockpit systems can be maintained.

 

I have been directly involved in the development of electronic devices for 30 years now and I can tell you that the components in state of the art display systems have a relatively short lifetime. By this I mean that the displays and the components to make the displays will probably be obsolete in five years or so.

 

Unless the manufacturer stockpiles a great number of these components, they will not be available in the future, making the expensive hardware junk!

Huh? Just because they are obselete does not mean they stop producing them. The G1000, 430, etc. are just composed of buttons, an LCD, and various computer chips. The only thing I could see to be in short supply is the buttons.

 

Garmin doesn't have their own chip fabrication facility and do not design their own chips. They buy off the shelf chips that should be easy to find for many years in the future and should be in production for a good while. Intel's 80186 was produced for 25 years and was obsolete for 23 of them. The 7400 series of basic logic gates was used in the 60s to make computers and are still in production today. I used the 7400 series in a basic digital circuits class in college a couple of years ago.

 

If you are talking about just the LCD technology, just because the screen technology changes doesn't mean that they can't make new parts. All that is necessary to make a new one is to get the same connector/interface with the same resolution and voltage requirements. Most embedded systems like the 430 and G1000 use some kind of standard serial interface to communicate with the LCD. I would bet in 20-30 years the embedded world will still use the same interface and chips will still be available. As far as making the actual LCD, I can't imagine it ever getting more expensive to make a run of 100-1000 4.3" 240 x 128 pixel screens or whatever the G1000 or newer screens use. As long as they keep the CAD data in an up to date format, any optoelectronics machine should be able to make them. I can guarantee the LCD in the 4.3" car and marine units is the exact same one that they use in the 430, so used replacement parts shouldn't be hard to find.

 

The only issue I see is that troubleshooting and repairing these obsolete units will take longer and require someone with more technical skill that the typical avionics shop repair person which will end up costing more because it has to be sent back to Garmin. This would make it more advantageous to buy a new GPS and maybe glass cockpit than to repair an old one.

[carusoam]

Welcome GameF.

What brings you to MooneySpace?

Best regards,

-a-

[Piloto]

Although many of the parts are common many of them are uniquely programmed for specific applications such as Programmable Gate Arrays (PGA), Memories (ROM), micro controllers and others. These components would need to be programmed before replacement otherwise they will not work even if the part number is the same. If the original programmer (manufacturer)is out business is a tough one to get a programmed part. You would need to get them from scrap products. The problem gets worse with later avionics products were gate density and complexity forces the designer to use programmable logic chips that simplifies design. At the airline MROs avionics shops the most they will do is to replace a whole PCB rather than an individual component. The troubleshooting complexity is so high that is not worth it the equipment and time cost.

José

[N201MKTurbo]

While it might be possible to build something like the G1000 using 7400 series logic, it would probably exceed the Mooney's gross weight limit. I mention displays because I've had two products I've designed that used off the shelf LCD displays, the displays became obsolete and we had to re-design the product. In both cases they were low volume products. We eventually redesigned them to use computer monitors although that wasn't as good a form factor as the built in displays. I just used displays as an example because my experience is that the vendors are constantly improving their process and building better, faster, higher resolution products and shutting down their existing production lines to build the new stuff, so the old stuff quickly becomes unobtainable.

 

The certification of avionics requires every part to be accounted for in the certification. If you change out anything it requires at least a re-validation if not a complete re-certification process. A redesign around an obsolete part can be a big undertaking and most manufacturers would rather spend their resources on next generation products leaving the products with obsolete parts as orphans.

[gamefreak32]

Although many of the parts are common many of them are uniquely programmed for specific applications such as Programmable Gate Arrays (PGA), Memories (ROM), micro controllers and others. These components would need to be programmed before replacement otherwise they will not work even if the part number is the same. If the original programmer (manufacturer)is out business is a tough one to get a programmed part. You would need to get them from scrap products. The problem gets worse with later avionics products were gate density and complexity forces the designer to use programmable logic chips that simplifies design. At the airline MROs avionics shops the most they will do is to replace a whole PCB rather than an individual component. The troubleshooting complexity is so high that is not worth it the equipment and time cost.

José

Yep, you are definitely still reliant on the fact that the manufacturer will stay in business in some form to provide replacement programmed circuit boards. I was looking for a replacement circuit board for a machine that was built in the early 80s that blew a couple of capacitors and melted the board about 3 weeks ago. Company did not exist anymore, but was bought out by Danaher. They could have shipped me a brand new programmed board in 3 days for $1200.  I was proving that Garmin was capable of doing this since they have the parts availibilty to make and program new boards.

 

While it might be possible to build something like the G1000 using 7400 series logic, it would probably exceed the Mooney's gross weight limit. I mention displays because I've had two products I've designed that used off the shelf LCD displays, the displays became obsolete and we had to re-design the product. In both cases they were low volume products. We eventually redesigned them to use computer monitors although that wasn't as good a form factor as the built in displays. I just used displays as an example because my experience is that the vendors are constantly improving their process and building better, faster, higher resolution products and shutting down their existing production lines to build the new stuff, so the old stuff quickly becomes unobtainable.

 

The certification of avionics requires every part to be accounted for in the certification. If you change out anything it requires at least a re-validation if not a complete re-certification process. A redesign around an obsolete part can be a big undertaking and most manufacturers would rather spend their resources on next generation products leaving the products with obsolete parts as orphans.

Just using the 7400 series as example for production life for obsolete parts. I do see what you mean, but I'm almost certain Garmin and other manufacturers have stockpiled plenty of LCDs if they have went out of production. I do know that the reason Garmin stopped making the 430/530 series is because the Intel i386 went out of production in 2007.

 

 

Welcome GameF.

What brings you to MooneySpace?

Best regards,

-a-

Shopping for a 201. Been lurking around here for a while due to the wealth of knoweledge. Currently not in a financial position to buy at the moment due to just getting out of school (NCSU '12) and not having two years worth of tax returns to prove my income to a bank.