10 pounds here, 5 pounds there, 2 pounds there...and soon you'll have enough weight savings to add a second survival pack full of gear! (Sarcasm)

I'm with Hammer if it's simply a matter of losing 10 pounds or keeping ten pounds. That weight is negligable to me and my style of flying when compared to the added benefit of hanging onto the vacuum.

However, if that ten pounds is another step closer to a goal you've set for you, your airplane and your style of flying then it makes a lot more sense and probably worth it. Risk/benefit/ultimate goal...

CW

bat443 wrote:In the end, to each his own; you've got to decide what makes sense to yourself, your budget and your mission.

Bingo. To that I would add, most of us understand how vacuum systems work well enough to explain it during a checkride. The electronics coming out recently are quite likely a whole new space for many, many pilots. I feel I have a good grasp on what can break, why it will, and how various redundancies will kick in. I know my electrical system intimately. I can also see how someone new to this or with higher stakes (part 135, hard IFR, etc) will have serious reservations about disrupting an understood mechanism that has served aviation for many decades, even if it does break with alarming regularity.

If you're going to make a decision on risk tolerance (which is what this entire discussion is about), you need to fundamentally understand the systems you are debating.

I would break it down risk this, display being generic (G5, Dynon, etc):
Single display, no vacuum: Single point of failure potential. May not be IFR legal depending on what you use. Power supply can be redundant with battery but unit itself can fail.
Two or more displays, no vacuum: Gives redundancy for electrical-only approach. Each unit can have individual battery backup, and often can run independent of other display. Shared sensors can still be SPOF but AI-related functions are generally self contained. Lack of vacuum means you're still 100% electrical-dependent. Chance of multiple independent failures very small, but not 0%. Dual G5's are IFR legal as long as turn coordinator remains, dual D10's are not (can't replace DG yet but DG could be made electric as well). Primary displays should be fine.
Vacuum backup added in: Redundancy not tied to electrical system in any way. Vacuum systems will fail over time and require some level of maintenance. Minor added weight, plus many moving parts. Best shot at always having situational awareness, but higher maintenance.

Also consider that if you go a primary display route (G3X, Skyview/HDX, etc) and remove steam gauges doing it, (my opinion is that) you should always have redundant displays and power regardless of flight regime. Losing attitude awareness is one thing, losing all instrumentation is quite another. That also brings up a separate conversation on keeping backup steam gauges like airspeed and altimeter, which some opt to do.

colopilot the statement you attributed to me was made by TradeCraft, just placing credit where credit is due.

colopilot, I agree, For me it is not a question of not trusting the new technology but of not betting my life on any technology. I am also the guy who doesn't trust his life to a hydraulic hose by walking under a forklift. For me personally, and I made a career of flying IFR, I have no interest in flying IFR with only needle, ball, and airspeed. If you are in the clouds with no visual reference the situation is the same until you reestablish outside visual reference, hard IFR or not.

A question for those of you that have a ADI in your airplane in case you need it some day, whither IFR rated or not do you practice instrument flying once a month so you are prepared if you need to use it? Do you think that having an ADI and being able to use it makes you less conservative in your weather decisions?

Tim (bat443)

TradeCraft wrote:

bat443 wrote:So I guess it comes do to how much of this weight chasing is for bragging rights around the camp fire or on the internet? Tim

There seem to be 2 groups of airplane owners in the 'backcountry' world: one counts ounces and the other will do anything possible to keep their plane far, far away from a set of scales....

Well...I think there's a third group: pilots who know what their airplane weighs, know what it could weigh if everything was stripped out of it, and are both heedful and happy with the compromise of utility-vs-weight.

You can strip a 182 down so far that you have to hand-prop it, and near half the rivets are gone, and it still won't fly like a super cub...it was never engineered to.

Spend a whole lot of money to turn a functioning wet-vac system into a secondary G5 and loose ten pounds in the process? Sure, if that's how you want to spend your money and it makes you feel happy, but it's a HELL of a lot of money to save very little weight on that airframe. Whether doing so makes flying IFR safer of less safe is debatable...highly debatable.

I don't say folks who make that choice are wrong, but the question was put the the general public whether it was a good or bad thing to do...to me it's a bad choice.

Less weight is always better, BUT!...I bet I could rip 150 pounds out of my little 170 for no cost other than my time, and 250 pounds if I wanted to throw money at it, but I won't, because doing so would either make it a less useful airplane to me and/or waste my money.

Could I land my 170 more places if it was 150 (or 250) pounds lighter? Probably...be pretty sad to say I couldn't. Do I have any compelling reason to land those places? Not really.

As far as the discussed ten pounds goes: If ten pounds is the difference between success and failure on any given mission, the pilot phucked up ROYALLY. Nobody can calculate that precisely. Yes...ounces make pounds and pounds make tons, but stripping ten pounds of interior out of an airplane costs you nothing, while putting in a G5 costs you plenty.

If money was no object none of us would be flying what we're currently flying...you have to draw the line somewhere.

bat443 wrote:.....A question for those of you that have a ADI in your airplane in case you need it some day, whither IFR rated or not do you practice instrument flying once a month so you are prepared if you need to use it? Do you think that having an ADI and being able to use it makes you less conservative in your weather decisions? Tim (bat443)

Had to google what an ADI was.
"Attitude direction indicator".
Most of us have one or the other, or both, not too many have it all in one instrument.
I do, in my G5.

No, unfortunately, I'm ashamed to admit that I only rarely practice flying on the gauges.
I've been saying since I installed the G5 that I should recruit a safety pilot and do just that....yet I haven't.
But I do realize that I have no business trying to fly on the gauges if there are any other options.
So re your other question, does it make me less conservative in my wx decisions, I would answer NO.

bat443 wrote:....As for 8 or 10 pounds, I am either not a good enough pilot for it to make a difference or a good enough pilot that it doesn't matter. For those of you that want the light empty weight,....I guess it comes do to how much of this weight chasing is for bragging rights around the camp fire or on the internet? ....

It's not just the lower weight--
one of my mantras is that simpler is (usually) better.
To replace a (failure-prone) vacuum pump, a regulator, a bunch of hoses, and a coupe of (failure-prone) instruments with a single simple electronic gauge is a no-brainer.

I know a lot of people who've had vac pumps fail.
I never have, but I'd had the DG's in my last 2 airplanes (C170 & C150/150TD) fail.
When they did, I just removed them along with all the other vacuum stuff.

With the 180, my replacement of all that stuff with a single G5 could be considered a preemptive strike.
Considering that I'm a VFR only pilot, and (per my last post) don't make the effort to maintain some sort of proficiency flying on the gauges,
I'm not sure I should have bothered.
The lack of AH & DG in my last two airplanes never caused me a problem,
probably wouldn't have in this airplane either.

I guess I should have said AH instead of ADI, would have been a more accurate description of what is installed in most light aircraft. Sorry, my bad. I have had more gyro's fail than vacuum pumps, so I have less faith in instruments, mechanical or electronic.



Tim

The vacuum system will be removed from my airplane when the Dynon HDX system STC is issued for the A185F. Not because of safety. I only fly VFR. Not because of weight. It's cheaper to put a pilot on a diet than to put an airframe on a diet. I could drop 40 lbs and save money!

The real deal is I'm tired of my airplane being broke down. Tired of leaning AIs. Tired of precessing or spinning DGs. Tired of failed vacuum pumps. Over the years it just seems that if it's not one item, it's another. They're also getting pretty expensive to repair/replace.

Of course the electronic alternatives have their own failure modes, but the fact is, they're solid state. They have no moving parts, and they offer more flight data. Magnetometer. Wind barb. TAS. HSI. Way more than an AI and DG can give.

Leaving the old stuff in, sure it's a backup, but it's not free. Your going to have to maintain and repair it forever.

Hammer wrote: it's a HELL of a lot of money to save very little weight on that airframe.

Making attempts at rationalization of any of it as practical or sensible is a dangerous road that will quickly lead one to a life without airplanes.

Scolopax wrote:

Hammer wrote: it's a HELL of a lot of money to save very little weight on that airframe.

Making attempts at rationalization of any of it as practical or sensible is a dangerous road that will quickly lead one to a life without airplanes.

Now THAT is a true statement! Good cautionary tale, too.

There's also some other advantages to the new whizbang stuff.
For example, you can connect a Garmin nav (even a handheld) to the G5 to drive the HSI.
And with or without a nav driving it,
you can connect the G5 to drive one of the new Garmin GFC-500 autopilots.

FWIW the new Garmin GFC-500 autopilot looks pretty slick.
List price is $7K, but I've already seen one outfit advertise them at $7K installed.

https://www.garmin.com/en-US/blog/aviat ... -aircraft/

Pinecone wrote:The vacuum system will be removed from my airplane when the Dynon HDX system STC is issued for the A185F. Not because of safety. I only fly VFR. Not because of weight. It's cheaper to put a pilot on a diet than to put an airframe on a diet. I could drop 40 lbs and save money!

The real deal is I'm tired of my airplane being broke down. Tired of leaning AIs. Tired of precessing or spinning DGs. Tired of failed vacuum pumps. Over the years it just seems that if it's not one item, it's another. They're also getting pretty expensive to repair/replace.

Of course the electronic alternatives have their own failure modes, but the fact is, they're solid state. They have no moving parts, and they offer more flight data. Magnetometer. Wind barb. TAS. HSI. Way more than an AI and DG can give.

Leaving the old stuff in, sure it's a backup, but it's not free. Your going to have to maintain and repair it forever.

True, I just had my AI overhauled this summer. In retrospect I should've just put that money towards another G5. I don't fly hard IFR but to be able to pop up every now and then would be nice.

I wasn't so concerned about weight, 10-15 lbs of the assorted vacuum stuff as I was about the cg and the firewall. I haven't had the w&b redone yet but probably will have the factory oxygen removed. I have never used it but the brace for the bottle blocks the area for extended baggage. That'll help when I stuff the gear that I have for unplanned landings further aft.

I'll wait until I run into another problem with the vacuum system and then remove vs repair. For now I'll just have two AI's.

Just my luck king 209 didn't work with my gps/nav so ended up taking the vacuum system out. The old stack plus dme and adf weighed a ton. Or something like 10lbs. MT prop should help out next year.