GI 275 / G5 redundancy?

[RobertGary1]

How do you ensure redundancy in your 275 or 5 install? Do you run the units off separate breakers? It would be awful if one bad breaker could leave you with no attitude in the clouds.

 

-Robert

[kpaul]

5 minutes ago, RobertGary1 said:

How do you ensure redundancy in your 275 or 5 install? Do you run the units off separate breakers? It would be awful if one bad breaker could leave you with no attitude in the clouds.

 

-Robert

My G5s are on separate 5 amp breakers.  Each also has its own 4 hour battery.

[RobertGary1]

1 minute ago, kpaul said:

My G5s are on separate 5 amp breakers.  Each also has its own 4 hour battery.

I'm installing 275's and their batteries are only rated a bit over an hour. Not sure if that is a difference in battery length or a difference in certification.

 

-robert

[kpaul]

Just now, RobertGary1 said:

I'm installing 275's and their batteries are only rated a bit over an hour. Not sure if that is a difference in battery length or a difference in certification.

 

-robert

That's interesting.  Of course for me an hour is probably enough.  If I have a complete electrical failure, I would not be continuing my flight longer than it took to make it to a suitable airfield. 

[aviatoreb]

I wonder why they only put a 1hr battery in the 275.  Vs 4 hrs battery in the G5 proves that yes bigger batteries exist.  I wonder how much the marginal cost would have been for them to have made a slightly larger battery?

Sure a lotta folks will correctly say that if there is an alternator failure and you are on instruments then job one is to divert and land asap and one should be able to get that done in under an hour.  But to counter point - when I hear it is a 1hr battery, I think, sure, 1 hr when new.  But just like my iPhone battery life keeps getting shorter and shorter as it ages, I wonder how long the actual battery life of a 1 hr battery would be a few years on if that day ever came that you actually need it.  50 min? 30min?  20min?  Wouldn't it be nicer to have started with a 4 hr battery that when "aged" actual life is down to half?

 I can't figure what went into that decision.

[EricJ]

31 minutes ago, aviatoreb said:

 I can't figure what went into that decision.

For a new product introduction the 275 just seems to have a lot of oddball decisions in it, the shorter battery life being just one example.

[aviatoreb]

On 2/8/2020 at 11:12 AM, EricJ said:

For a new product introduction the 275 just seems to have a lot of oddball decisions in it, the shorter battery life being just one example.

They make funny decisions sometimes.  I mean I can't figure why they didn't go a country mile to make this thing much much simpler to install so that it would be low-hours cost to install.  As it is, the high hours cost to install will make this thing cost comparably to aspen, or if getting two, then comparably to G3x.

They made the same kind of high cost to install decision when they made the GTN650/750.  The 650 should have been a slide in replacement for the GNS430W and they would have killed it.  The competitors proved it can be done.  I understand why the 750 is not plug and play because it is huge vs the 530 but the 650 should have been.  So I see the same kind of design arrogance a bit in this 275.

Edited February 12, 2020 by aviatoreb

[RobertGary1]

1 hour ago, aviatoreb said:

They make funny decisions sometimes.  I mean I can't figure why they didn't go there country mile to make this thing much much simpler to install so that it would be low-hours cost to install.  As it is, the high hours cost to install will make this thing cost comparably to aspen, or if getting two, then comparably to G3x.

That’s one of the selling points of the 275. It fits where standard round instruments fit.  Unlike the g5 where you have to egg out the holes to put one above the other. 

To be clear it’s  not clear if the battery on the 275 lasts less time than the g5 or a function of coming up as a certified instrument vs the g5 which was an experimental instrument that they were about to get certification for simply by showing the accident rate of not cerifying  it was more than certifying it. 

The 275 has a health meter I’m told that tells you what it’s current capacity is. The iPhone does that too if you go to the battery health menu. 

 

-Robert 

[RobertGary1]

The 275 can be installed on the citation etc so the certification of the battery is more intense. 

-Robert 

[wcb]

21 hours ago, kpaul said:

My G5s are on separate 5 amp breakers.  Each also has its own 4 hour battery.

The G5's should not only be off of seperate breakers but also one should be off the main bus and one of the aux bus.  In other words one that turns on and off with the main and one that turns on and off with the radios.  I assume it would be the same with 275 and g5

[Andy95W]

55 minutes ago, wcb said:

The G5's should not only be off of seperate breakers but also one should be off the main bus and one of the aux bus.  In other words one that turns on and off with the main and one that turns on and off with the radios.  I assume it would be the same with 275 and g5

Different breakers, yes, but I think the different bus idea might have changed.  I've been reading through the G5 install manual and can't find that reference anywhere, but I've seen it posted here often.  I think it might have changed when they realized that with the battery backup it isn't really essential any more.  But again, I'm not sure and I might've missed it in the manual.

[kpaul]

3 hours ago, Andy95W said:

Different breakers, yes, but I think the different bus idea might have changed.  I've been reading through the G5 install manual and can't find that reference anywhere, but I've seen it posted here often.  I think it might have changed when they realized that with the battery backup it isn't really essential any more.  But again, I'm not sure and I might've missed it in the manual.

Pg. 81 of REV 21

• G5 needs to be connected to the battery bus when installed:  

-As an Attitude Indicator (ADI),

-installed in either the turn coordinator or attitude indicator position

• G5 needs to be connected to the avionics bus when installed: 

-As a HSI

-In the DG position 

[Andy95W]

That's newer than the bootleg version 9 I've been reading.  Thanks.

[chrisk]

On 2/7/2020 at 3:13 PM, RobertGary1 said:

I'm installing 275's and their batteries are only rated a bit over an hour. Not sure if that is a difference in battery length or a difference in certification.

 

-robert

I'm thinking of getting a 275.  Are they available now?

[kpaul]

49 minutes ago, Andy95W said:

That's newer than the bootleg version 9 I've been reading.  Thanks.

https://support.garmin.com/support/manuals/searchManuals.faces?refresh=true

you can get all of the manuals here

[RobertGary1]

46 minutes ago, chrisk said:

I'm thinking of getting a 275.  Are they available now?

Yes although my shop says there is still confusion about aspects of it, especially what it can integrate with. They just had a Garmin rep tell them it couldn’t interface with a certain autopilot then another call them back and said they were wrong, that it can. So that’s slowing installs. 
but I just took at look at an install they did just as a cdi. The heads for gps indicators are so expensive these work well in that role too. 
 

-Robert 

[chrisk]

11 hours ago, RobertGary1 said:

Yes although my shop says there is still confusion about aspects of it, especially what it can integrate with. They just had a Garmin rep tell them it couldn’t interface with a certain autopilot then another call them back and said they were wrong, that it can. So that’s slowing installs. 
but I just took at look at an install they did just as a cdi. The heads for gps indicators are so expensive these work well in that role too. 
 

-Robert 

I'm looking at replacing my KI-256 attitude indicator.  Its the last vacuum instrument that I have.  That said, I find the requirements difficult to come by.   For example, I have an ASPEN pro.  Can I use the GI-275 as a primary or backup AI?  I think so, but I still need to double check.  Does the GI-275 require GPS to work as an AI?  I think so, and I am not real happy about that, but again I need to double check.  It might seem silly, but if the FAA wants to keep a MON for VORs in case GPS doesn't work, maybe I want a plane that doesn't need GPS to fly IFR.  Are there any other digital AIs certified as primary, that don't need GPS?  Maybe RCA2610?     

[chrisk]

5 minutes ago, chrisk said:

I'm looking at replacing my KI-256 attitude indicator.  Its the last vacuum instrument that I have.  That said, I find the requirements difficult to come by.   For example, I have an ASPEN pro.  Can I use the GI-275 as a primary or backup AI?  I think so, but I still need to double check.  Does the GI-275 require GPS to work as an AI?  I think so, and I am not real happy about that, but again I need to double check.  It might seem silly, but if the FAA wants to keep a MON for VORs in case GPS doesn't work, maybe I want a plane that doesn't need GPS to fly IFR.  Are there any other digital AIs certified as primary, that don't need GPS?  Maybe RCA2610?     

I went and looked up the GI275 and found the following

ADAHRS
The integral ADAHRS, included in the GI 275 -10/-30 variant, senses aircraft
attitude and air data for GI 275 display of primary flight data and can provide
attitude and air data for use by other installed systems.
The ADAHRS requires GPS and airspeed inputs for aiding the system. GI 275
includes an optional GMU 11 or GMU 44B magnetometer interface to
determine magnetic heading and an OAT probe for measuring outside air
temperature.

[aviatoreb]

20 hours ago, RobertGary1 said:

That’s one of the selling points of the 275. It fits where standard round instruments fit.  Unlike the g5 where you have to egg out the holes to put one above the other. 

Separate from how big a hole one needs to install it are the technical aspects of installing a GI275 that from appearances and second look seem very substantial, so that all in, the hours required to install a GI275 look like they will be substantial and very expensive.  So if installing 2 GI275's becomes sufficiently expensive, including all hardware and hours, becomes same or more than a Aspen then I don't see it as what looked initially as a new game changer route.

[RobertGary1]

5 hours ago, aviatoreb said:

Separate from how big a hole one needs to install it are the technical aspects of installing a GI275 that from appearances and second look seem very substantial, so that all in, the hours required to install a GI275 look like they will be substantial and very expensive.  So if installing 2 GI275's becomes sufficiently expensive, including all hardware and hours, becomes same or more than a Aspen then I don't see it as what looked initially as a new game changer route.

My shop says it’s less labor than a g5 just because of the conforming form. 
-Robert 

[RobertGary1]

5 hours ago, chrisk said:

I'm looking at replacing my KI-256 attitude indicator.  Its the last vacuum instrument that I have.  That said, I find the requirements difficult to come by.   For example, I have an ASPEN pro.  Can I use the GI-275 as a primary or backup AI?  I think so, but I still need to double check.  Does the GI-275 require GPS to work as an AI?       

All the AHRS systems I’ve aware of require gps. They use it to make small corrections. I volunteered for a project that was a homebrew attitude indicator using an off the shelf AHRS chip and it performed poorly until we introduced gps to help with corrections. 
 

-Robert 

[Austintatious]

On 2/7/2020 at 3:03 PM, RobertGary1 said:

How do you ensure redundancy in your 275 or 5 install? Do you run the units off separate breakers? It would be awful if one bad breaker could leave you with no attitude in the clouds.

 

-Robert

Well, aside form the built in battery, I have a KI256 and a turn and bank.  I feel like this is plenty of redundancy.

[RobertGary1]

19 hours ago, Austintatious said:

Well, aside form the built in battery, I have a KI256 and a turn and bank.  I feel like this is plenty of redundancy.

For the same reason I'm going to keep my vacuum attitude off to the side. Its odd to me when people say they're so excited to get rid of the vacuum system. I don't understand why unless they are having issues with it. Its the cheapest attitude indication you'll ever find.

 

-robert

[201wantabe]

On 2/8/2020 at 11:12 AM, EricJ said:

For a new product introduction the 275 just seems to have a lot of oddball decisions in it, the shorter battery life being just one example.

Actually the battery is the same size, the GI-275 is just far more power intensive. Keep in mind the G5 was originally intended to be a backup to a G3X Touch system with the original design goal to have 1 hour of battery life, it turned out they over-sized the battery and it did not make sense to move to a smaller battery. The GI-275 was designed from the ground up to be a primary instrument rather then be a standby so it has many more features thus it consumes the battery in a shorter period of time. 

As far as install goes, for the G5/GI-275 your required to have a breaker for each element in the system, so for example if you have my setup which is dual G5s, a GAD 29B, GAD 11 and GAD 13 I have the following breakers:

• AI
• HSI
• Mag
• GAD 29
• GAD 13

Read the STC for more information, both the G5 and GI-275 have very well laid out documentation for install, almost any some what technically minded pilot has the ability to install a dual G5 system with the guidance of an A&P, I also highly recommend have spruce make the harness. The worst thing I had to do was add a few pins to the harness on my GNS 480. 

[Andy95W]

That's my actually too many circuit breakers.  The current installation manual (thanks @kpaul) says the GMU should be powered from the G5 HSI breaker, and both GADs share a breaker.