Yeah, but 50% increase on fsck all is still fsck all (especially when passives will make up less than 1% of the BOM cost).
Over in the UK getting a Garmin dealer who can install anything ahead of Q2 2022 would be a challenge. Avionics, paint shops, engine shops etc are all out the door busy.
WilliamF wrote:
Over in the UK getting a Garmin dealer who can install anything ahead of Q2 2022 would be a challenge. Avionics, paint shops, engine shops etc are all out the door busy.
Just got an offer of June ’22 for an Aspen/IFD 440 install!
Avionics, paint shops, engine shops etc are all out the door busy.
IMHO that is because so many people are not flying (partly because they can’t face the planning/paperwork issues with CV19) so they have increasing money burning a hole in their pockets 
If they were installing aftermarket turbos, I would understand that, but avionics?? The other day I saw a pic of an 80k install in a plane not worth much more. It’s almost like this – 35k spent on a 35k plane.
Just got an offer of June ’22 for an Aspen/IFD 440 install!
That’s crazy. Buy one from the US and get some freelance installer. If you aren’t N-reg you used to have to buy a brand new one but this should avoid that.
50% increase on fsck all is still fsck all
Exactly; passives are a non-issue currently. Some oddball parts like 0805 inductors have been but there are multiple mfgs.
Firms like Garmin are using a lot of long-discontinued parts though, and their only option is a stockpile. I’ve done the same for a key CPU at work – something like a 10+ year stockpile. It’s not a total risk because once no longer needed it can usually be flogged off to the surplus stock distis in the US. Anyway the gross margins in avionics are massive – of the order of 90%. The parts in a GTN650 are only a few hundred $.
The really big problem is colour LCDs. AFAICT the KLN94 was dropped (2011 or so) because they could not get the LCD. The LCDs get damaged by “pilots” who think it is a touch screen so they poke it, and when it doesn’t work they poke it really hard Obviously you can get custom made LCDs but only in decent volumes – 10k-100k, I would think.
Peter wrote:
The really big problem is colour LCDs.
The GTN 750xi and 650 xi are constrained, The GTN 725xi and 625 xi are not. That suggests that the display is not the issue. The difference is that with the 725xi and 625xi, they don’t include the VOR/ILS Nav receiver and VHF Com capability. Other systems that are constrained have either a VHF com or ADS-B In receiver. The GTX 335 is not constrained, but the GTX 345 is.
Sorry; what I meant was that LCDs are a problem with long term component obsolescence.
Actually most complex chips are e.g. CPUs, FPGAs, but those tend to have a decent life (so long as you avoid Atmel who drop chips faster than [the old joke about knickers] 
) but many have an amazingly long life. I sell a product on which the Hitachi H8/323 had a 25 year production life.
Funnily enough, the original popular 8-bit chips are still made (both the Z80 in 6502 are still manufactured – although CMOS these days. The former still made by Zilog, the latter by Western Design Center, as MOS disappeared years ago with the collapse of Commodore). I suspect they are in all sort of industrial products that were designed years ago, just work, and don’t need to be changed. And the non-sexy side of semiconductors – MSI logic (74HC/74HCT series), things like 555 timers and some really ancient op-amps, are still being churned out in their hundreds of millions.
I think if I was making a Z80 based product, and there was enough “juice” in it, and the code could not be re-done, I would look at replacing it with an ARM emulating a Z80, or with an FPGA containing a Z80 block.
The art of electronic design for a long product life, never before highlighted as strongly as in the past year or so, is to use old commodity parts where possible. An old guy will use a boring LM358 from the early 1970s (20p) while a young college “EE” graduate will use a sexy one from LT or Maxim (£1.50)
The problem is that in a big company you can’t control this – because there is nobody in charge of that aspect. The “old guy” is now playing golf. When you look at the MM for say the KFC225, it is obvious that the designer just used whatever he wanted. There are bizzare resistor values like 10.2k (E96 range) where 10k would be perfect. The result is that HBK has (had!) to maintain a vast stock of parts; probably 10x bigger than necessary. While E96 resistors are not a problem in itself, the lack of design supervision means that a lot of other parts would have been desgined-in which have since become a trap.
However I suspect Garmin got caught by something other than a Z80 These boxes use weird “industrial” 80×86 processors – the obvious route because you can write the code on a PC, but a trap because PC parts go out of fashion fast, so you have to take special measures. Also production life <> availability… Garmin is halfway up the pecking order between (a) the car and phone makers, and (b) the “nobodies” like my business. They don’t have any real power, but have enough cash to multi-order, and it is companies like that who caused much of the present mayhem.
Garmin used an embedded version of the 80386 in some of its products. While the Z80 is still made, Intel dropped the 286 and 386 over a decade ago, including the embedded versions.
You can still write the code on a PC for anything else, cross development has been a thing in software for years (so far back that the Sinclair Spectrum ROM, IIRC, was written on a VAX which is as foreign as you can get as an architecture, and this was back in 1981). I would make a wild guess that it was more a familiarity thing with Garmin (the guy designing it knew x86 asm, and the x86 MMU, and didn’t want to have to re-learn it for ARM or another architecture).
I thought there was another thread somewhere on overall supply chain issues (related to engines etc.) but I cannot find it (Peter, apologies I know you’re skiing). This just landed in my inbox from AOPA
https://www.aopa.org/news-and-media/all-news/2022/january/13/volatile-supply-chain-tightens-grip-on-aviation-industry
