I am not the OP 
And yes, FWIW, I am always prepared to fly an IAP to minima. That is what an IAP is for. You fly them as published. In reality if going somewhere nice one doesn’t fly in bad wx there but one could encounter it and one has to be ready for it. Even going EGKA-LFAT I have done the ILS to minima a few times, due to low cloud, and then had a perfect day there as expected.
3 x GI275 doesn’t give you redundancy from the same bug – see the other GI275 threads.
The third GI275 one doesn’t add redundancy, but it’s an approved EIS, to replace the original and often non working gauges of the TBs in the top central console. There are other approved EIS, in the same ballpark in terms of price, and it would just make it a nicely integrated one. But for sure, going this route, I will need a real separated backup.
You’re right about doing IFR SEP in a TB10, you can only do good weather IFR with a sole heated pitot, as soon as you don’t ice, and I would feel very uncomfortable in frontal weather. It’s all about staying current in doing a bit of IFR.
Peter wrote:
Peter23-Oct-23 19:2931
I am not the OPAnd yes, FWIW, I am always prepared to fly an IAP to minima. That is what an IAP is for. You fly them as published. In reality if going somewhere nice one doesn’t fly in bad wx there but one could encounter it and one has to be ready for it. Even going EGKA-LFAT I have done the ILS to minima a few times, due to low cloud, and then had a perfect day there as expected.
3 x GI275 doesn’t give you redundancy from the same bug – see the other GI275 threads.
An instrument approach allows for an approach according to the category (and noteworthy not distinguishing between SE and ME airplanes) down to established minima/minimums (not below without required references). That doesn´t mean this minimum is “suitable” to the individual operator pilot (and his equipment (including an SEP)), it just defines the minimum (legal) for the approach. It´s very important for any IR pilot to understand that you don´t, and very often shouldn´t (SEP), plan on this (unless of course your risk assessment is somewhat risky – in my subjective perspective). Flying IMC with low level weather/low VIS, including IFR approaches on SEPs, will always carry a risk – that goes equally for planned or unplanned scenarios.
That being said, it is perfectly possible that the choice of an SEP IFR approach in IMC, as opposed to a limited VMC approach, is a safer choice between the two. But to plan on it – not my cup of tea on an SEP.
Regarding the GI275s. Screen failures are individual, as are individual component failures, and this can easily transpire into loss of redundancy on a single unit (multiple instrument display), where´s a multiple display setup will allow for continued safe flight as well as greater dispatchability (with a single unit failure).
It is not about the good times we leave behind us, and walk away from, it´s about planning for the worst in a safe and sensible way. Even on non-commercial private pilot flights – this has to be considered.
greg_mp wrote:
The third GI275 one doesn’t add redundancy
That´s correct. The second GI275 does do that though – from what I understand.
Not entirety actually, some dual failure did happen, probably due to sw bugs.
greg_mp wrote:
Not entirety actually, some dual failure did happen, probably due to sw bugs.
Sure thing (about dual failure), but the second certified instrument display legally provides for redundancy and dispatchability – a single display doesn´t. SW bugs is just one possible point of failure – there many more (and more likely failure points than SW bugs).
I do have to confess that I am not entirely sure about the certified Garmin 275s – and the backup capabilities – just limited knowledge, so I stand to be correct on this.
Yeager wrote:
but the second certified instrument display legally provides for redundancy and dispatchability
I take the point of the legality of the second GI275 backup, but actually I am not that interested into goin for the legal minimal.
This is what surprised me in this story
https://www.euroga.org/forums/flying/13153-loss-of-control-and-high-speed-after-losing-attitude-indicator-gi275-dual-failure
Why This guys only flies hard IFR with only the backup function of a dual GI275?
On the G1000 IFR equipped planes I have flown and seen, you have 1 PFD and an MFD that could act as a PFD as soon as it detects a failure of the main PFD or if the backup button is pushed. But in any installation, you have a supplementary electronic backup ASI and Horizon. As soon as displays are linked with any cable other than power supply, they must not be considered as a valid backup.
@greg_mp not sure you got the time (nor the desire…) but the guys at angle of attack have published a series relating the makeover of their 172 panel, one of them here:
Now re the GI275, given the choice I’d retain my dual G5 (both with batt back-up) / GNX375 / AV-20S (with battery too). IFR capable, and probably one of the cheapest variants for a Garmin set-up. For a homebuilt one could go cheaper using GRT or MGL.
Having seen the GI275 briefly at work, I just find it too crowded, too much stuff is such a little space. The G5 presentation is much clearer… as an example (private opinion only 
) terrain presentation has nothing to do on a PFD. Either you’re VFR, and look out, or IFR, and know where you are.
What led to the sharp decline of CFIT was not only the birth of GPWS (and all its variants), but above all GPS, giving one accurate location without the need on guessing needles vs distances…
One thing I’d do different on my panel though, is to install a GNC255 (with VOR/LOC/GS receiver), which is now available with 8.33 spacing, iso of the GTR225 (COM only) I have installed. Though my GNX375 has all the LPVs, I came to realise that some countries, such as the UK, are very slow in publishing such approaches…
The GI275 is way too crowded if you enable everything. Same as my Sandel SN3500 (I have two of them).
What led to the sharp decline of CFIT was not only the birth of GPWS (and all its variants), but above all GPS, giving one accurate location without the need on guessing needles vs distances…
Do you mean in airlines? That would have been INS originally. And yes GPWS.
GA has continued to have CFITs in good numbers despite GPS.
greg_mp wrote:
On the G1000 IFR equipped planes I have flown and seen, you have 1 PFD and an MFD that could act as a PFD as soon as it detects a failure of the main PFD or if the backup button is pushed. But in any installation, you have a supplementary electronic backup ASI and Horizon. As soon as displays are linked with any cable other than power supply, they must not be considered as a valid backup.
The G1000 has a single AHRS so the double displays don’t add anything to the redundancy. At least for your typical a SEP. G1000 installations with dual PFD displays may also have dual AHRS.
