Reliability of Instruments

Scott Sherer

OK, after 52 years of flying I drank the kool-ade. 52 years of vacuum pumps, pressure valves, air driven attitude indicators and directional gyros. No failures, ever. Two years ago I bought into the "better reliability" marketing pitch for electronic instruments. In the last six months there's been an AD on Aspen PFD's limiting their use and yesterday an Emergency AD on my Sandia 340A backup attitude indicator. My plane is now VFR only. And this is reliability?

griff390

Scott; sorry to hear what you are going through. As someone who has been in the computer and high tech industry since the late 1800's, I have seen almost every failure mode possible, including some that "...will never happen...".
Until it does.
That's one of the reasons I have not switched over. Yes, they have their failure modes too, but there is something to be said for the simplicity and reliability of steam gauges. I have some glass in my cockpit, but the trusty old 6 pack is still center stage. As preventive maintenance, I have the vacuum pump replaced every 400-500 hrs whether it needs it or not. It's very cheap insurance.

Scott Sherer

Thanks Griff. This will pass, of course. I'm just really glad that I don't have a G1000 first gen in my panel. Those are now 15+ years old. Or the early Avidyne panels used in 20 year old Cirrus and Piper. When they go, megabucks.

griff390

Scott; you just nailed the 2nd big reason, obsolescence. Steam gauges have been around since before WWII, and remain viable, while glass systems will eventually become obsolete and/or no longer supported. During the rapid computer rise in the 80's and 90's, computer technology was moving so rapidly that systems were obsolete every 18 months. That's the nature of technology.

asikora1

this conversation is making me rethink what I do next. Eventually hope the whole panel but can't afford it all at one time. Even though everyone says do as much as you can at one time to reduce install labor. Next step won't be till next year sometime. Sorry for your hassle, Scott. Hope there is an affordable fix coming!

arrow76r

Backups are still prudent...hence my choice of dual G5s where the HSI can revert to an attitude indicator if necessary and I maintain my KX-155 with a separate CDI indicator for backup com and nav. My GPSMAP 396 provides backup GPS (separate GPS antenna) and Sirius XM weather as well as being a backup source for the autopilot (which the KX 155 will also permit). The newly installed JPI EDM 830 has become my primary engine monitor BUT the analog gauges are the backup now. A Garmin InReach Mini PLUS a SPOT device provide tracking and a PLB in the "go bag" provides triple redundancy for off airport landing notification. A Sporty's hand-held (SP-400) provides backup com/ILS/VOR nav in case of aircraft main bus failure. Last, but not least, is that I always request (and am rarely denied) VFR flight following if I am not on an instrument flight plan. One thing I do NOT have (yet) is a pair of suspenders to backup my Philmont Scout Ranch belt!!

griff390

Jim T.; absolutely agree with layered backups. I have some glass, some steam gauges, a backup iCOM handheld radio with built in VOR, a "lap mounted" tablet running iFlyGPS that is integrated to the ADSB, but can operate independently and will run at least 4 hours on it's own battery. The iFlyGPS app has it's own integrated instrument panel if necessary, as does my handheld GPSMAP 496 that is integrated with a Zaon PCAS and will also run at least 4 hours on it's own battery. My final backup is a paper chart.

Scott Sherer

Thanks so much for your comments, fellows!

arrow76r

Griff...two peas in a pod! I forget to mention I also carry "paper" in the form of SkyNav Charts' bound atlas of WAC charts. My iPad mini (running ForeFlight) does not have GPS but I can connect my Garmin GLO device or the little Bad Elf dongle to the iPad or cell phone for good GPS reception.

Scott Sherer

So here's the deal with Sandia Labs and my Quatro 340 backup PFD that cost about $5k to install a little over two years ago. I emailed and called three times and no response. I got them on the fourth communique. They don't know what's wrong. The don't know what it's going to take to fix it. It's going to be months and months while I'm placarded for day-VFR only, their best guess. So much for electronic reliability.

arrow76r

Scott...who would guess 2 ADs would occur simultaneously. I gave up on the Sandia unit after 3 different device failures several years ago (took a bath on that!) and went the dual G5 route for redundancy.

griff390

It hurts just reading both of your stories. As much as I wanted to upgrade to a glass cockpit, I hedged my bet because of what I've learned being in the high tech industry for the past 40 years. I've had both of my handheld GPS's fail at the same time for different reasons. What are the odds? Doesn't matter. It happened, so the odds were 100%. When you have 30 seconds to make a decision (and if you're ahead of the plane, that's plenty of time), but it takes 3 minutes for the equipment to reboot and resync, that's when I appreciate the steam gauges. That being said, I really like the G5, and the Avidyne system and may install one or the other as secondary instruments regardless.

Scott, I'm really sorry to hear you're being pulled through the wringer. If I can say anything positive, VFR is better than NO FR, but that just plane sux (lame pun noted). Keep the faith brother...this will pass.

Scott Sherer

Roger that, Griff. I'm beginning to formulate a plan. Right now I'm looking at an overhauled electric (iron gyro) attitude indicator. Less than $1k and fits in the same hole. Just plug in 12vdc.

arrow76r

Has the Aspen AD been resolved? I gather that you need a backup of one sort or another and I'm pretty sure the iron gyro will hold its value.

Scott Sherer

Hi Jim,
Yes, my Aspen Pro-1000 PFD is fine, AD resolved. The Sandia is my backup.

arrow76r

Well that's the silver lining then so you wouldn't be limited to VFR day if you go the iron gyro route.

Scott Sherer

Thanks Jim.

MikeJJ

Scott, you could also try the Cat and Duck

Lon Stratton

I've been trying to get the King KI-300 (Sandia 340) for YEARS! I'm so glad it was never really available to me or I'd be in the same boat right now. I'm re thinking to just keep my analog gauges. I do have an electric AI as a backup as well as an electrically driven secondary vacuum pump.

Scott Sherer

Hi Lon, I'm looking at an electric AI right now as it might be the cheapest solution. In the meantime, I'm Day VFR.

Warrboo

Great thread. I fly glass/FMS for a living. With my fun flying I like to keep it “old school”. I’m one too to have back-ups for the back-ups. I was never quite comfortable to solely rely on Foreflight for my charts and had paper backups. But only carried plates and 10-9 pages for airports by the “home drone” and my alternates.
Picking my way through an intense line of storms, I had decided the best course of action was to divert to an airport that was on the west side of a fast easterly moving line of storms. Changed my destination with ATC and was immediately put on vectors for an ILS...
Although I filed an alternate for my trip and had the alternate “packed” in my digital charts, I had zero charts/plates/10-9’s for the airport that was to be my home for the next 4 hours. Long story longer...tech is great and makes flying easier, having a chart case for an entire area (old school) would have been nice.

Bantlejohn1

While I have never lost a vacuum pump due to frequent replacements I have replaced 3 AIs, 3 DGs and 1 turn and bank due to failures in 20 years of PA28 ownership. I now have a Garmin G5 and it seems to be working just fine.

Scott Sherer

Thanks for everyone's comments.

ScottG

For starters, an individual's singular experience is almost never going to be a reliable indicator of failure rate for everyone. Though of course, anecdotal experience is still useful.

While I like the steam gauges ok and even did IFR training with ye' ole' NDB as a required element, I very much prefer the new stuff. In our club aircraft, (all 7), we've moved to Aspen Evolutions in most of them and just got a Dynon SkyView in one plane. There's more to learn. The Aspen is one thing, but the Dynon has its own non-trivial learning curve. (Not to mention setup.) But the benefits are simply stunning. From flight planning to situational awareness to weather and traffic... wow. But yes, as a maintenance coordinator I too have to sort out some time to bring one of our Arrows in to have a software update on the Aspen. And yes, some EFIS systems can present single point of failure for multiple instruments. But when they do, it's really clear there's a failure and you go to backups. (Though we haven't experienced this kind of failure; yet.) It's not like the insidious failure of a vacuum pump or partial blockage in a pitot static system. You'll know what's wrong right now.

And what about maintenance on steam gauges? It's not like they don't require heading to the shop every so often. And which shop? This one is good with vacuum systems, this one for avionics, that one for... etc. etc.

As for obsolescence? Yes, it's possible that we won't get 20 years out of our 'new' stuff. But I'm not sure I'd personally want that anymore. Big expense hits can be hard, but steam gauges go bad too. Over 20+ years how many of those need replacing? We've had the Gamin CNX 80s for 17 years. We were - I believe - among the first to be flying STC approved WAAS navigators. Maybe not everything lasts that long, but for reliable manufacturers, you'll usually get a good run.

Personally, my biggest issue? Printing a few charts as backup. Since going to ForeFlight, I no longer need to carry those huge Jepp books. (Can't bring myself to throw them out as they have my dad's name on them, but...that's still a bunch of pounds out of the flight bag.)

So... having some backups, electrical or otherwise, of course you need that. But steam vs. EFIS? I think the benefits - including safety - argue for the new over the old. And I hate to use too extreme an example, but... let's say critical failures in EFIS - just for the sake of argument - killed 5 people in a year. In that same year, how many might have been saved by it over steam? Not sure anyone's done such a study yet. Supposedly, the accident rates for TAA aircraft are about the same. But one theory is that pilots are nibbling closer to the edge because synthetic vision can sucker you a bit below MDA/DH. Anyway... long post, but that's my take on this so far.

Scott Sherer

Thanks ScottG, much appreciated.

BillCorbett

Scott sorry to hear that, so i feel I am falling down the sucker hole. I started with a simple radio stack upgrade, got rid of a adf,dme, II morrow gps, kx155, transponder. Putting in 350C audio panel, 430W, keeping the 420, used 330ES and right stack is the Aera760.
While I was getting this done I wrapped the dash in carbon fiber after seeing Scott's dash! Looks awesome. So i was talking to my shop and I thought it would be a good time while in the dash to get rid of the vacuum system and add an Aspen E5. Was over my budget but thought it would be worth the savings in install. So last week they told me I couldn't hook up my IIIB auto pilot without spending a bunch more on the interface modules. So by the time I pay for the modules I may as well spend a few dollars more and put in the trutrak ap.
After reading this thread i'm second guessing myself. Bob had a really good article on autopilots and I would like a 2 axis ap. Starting my ifr and want a good one. Or do I stick with the steam and radio stack upgrade for now? TT ap is 45-60 day lead time( then shipping to Canada). Going to call and see if i can get a wiring harness so we can put the plane back together? Add the rest of the ap in December.
Whats the reliability of these new ap's, I have not read anything negative, just positive.
So Radio stack or everything?

Warrboo

Not to derail the thread, but you state “start my IFR”...does that mean to get an IFR rating? As a professional pilot, and former CFI, II, MEI, don’t let the 2 axis AP become a crutch. There is something to be said about hand flying in the soup, descending in a turn while
being bounced around, moving your head around to find the approach plate or iPad you dropped....all with your CFII in the right seat watching it all unfold.....IT WILL SCARE YOU. And we all know what doesn’t kill you makes you that much better. As far as 2 axis autopilots....a well maintained legacy Piper/Century will reliably bring you right down to MDA like it’s nothing, much less these modern digital/solid state AP’s.

Scott Sherer

OK, let's talk autopilots. STEC, Garmin and Trutrak all make excellent and well supported autopilots. They work forever and are totally reliable. Century used to be the go-to autopilot company but no more. And Bendix King just bought a company that makes autopilots (name escapes me,sorry) but I hear they aren't supporting it very well. I would get the new autopilot and your plane will be perfect. And if something fails (like I've experienced) just deal with it like I am. It's worth the hassle. Just my opinion

arrow76r

I second Scott's comments. I fly solo 99.99 % of the time and in both IMC and night VFR. I started with an STec 30 autopilot to help reduce the workload then incrementally added capabilities like automatic altitude hold, then GPS roll steering (GPSS) and now vertical speed, altitude pre-select, decision height and altitude awareness, et. I can TASTE the newest STec 3100 BUT unfortunately Cobham (STec) has not certified the 3100 for the PA28 models and, apparently, has no plans whatsoever to do so. I briefly considered the comparable Garmin system but that would entail removing all the STec servos, wiring, etc. for which I could probably only receive pennies on the dollar in selling those items. Too bad Cobham apparently thinks the PA 28 series are "toys" as they already have certified the 3100 for the PA 31,32, and 46 models with the PA 24's next in line but no plans at all for those who fly the lowly PA 28 Cherokees. Regardless of which brand you choose, the autopilot, properly used, can be a great asset but does NOT preclude basic "hands-on" flying skills in IMC as the OP posted above.

Scott Sherer

And note that the STEC 55x in the PA-28 is awesome! I have one.

arrow76r

Bill, the important thing about autopilots is that they are an aid, not to replace a skilled pilot. I'm sure Scott would agree!