Many Cirrus pilots (me not) have replaced their GNS430/430Ws with IFD440s and I have never heard a bad thing – except some SW issues with the first version.
In your position (building the panel from scratch) I would go for it. In fact, I’d say it’s a no brainer if you plan IFR flying. I have legacy stuff I’m slowly ripping out and replacing it. GTN 650 may go in this winter. Can’t speak to Avidyne question.
You have confirmed with the LAA what you need to get your UK RV certified for IFR, of course.
I have read all the documents and am very clear what’s needed. First mod is going in now, cowering a second alternator and battery.
The radio nav is the final piece of the puzzle.
After doing some measurements today, it’s bad news. Even a GTN650/IFD440 doesn’t fit. So I’m going to be making a new panel, just to shuffle things around a little. The project keeps getting bigger :(
I still can’t motivate myself to spend a 5 figure number on a WAAS Navigator. For the type of operations I fly which will get me LPV in stead of LNAV with my current KLN90B. I closely monitor the change once during the approach from 5Nm to 1Nm to 0.3 the plot on my GPS is rock solid after the FAF when coupled in APP mode. Though if I had to choose the IFD440 would be my preference from HMI point of view. Having sad that active TAS would be on a higher list of safety items then LPV capability. My only worry is the support from Honeywell for the data base support. Installations of equipment have also other (expensive) cascading effects …radio rack adjustments, antenna removal installation etc…
Why don’t you simply buy a good used GNS430W? I am very happy with mine. Much more capable than a KLN90B.
AFAIK you cannot fly LPV approaches with the 90B.
Edit: Sorry I misunderstood your post. Looks like you are aware that the 90B cannot do LPV. I would highly recommend LPV though!
Cause the whole job would still be 10 grand. A KLN90B doesn’t fetch more than 1k on the used market…
And after spending these 10k, he would still have a very old piece of hardware in his cockpit.
Like many, I have delayed going WAAS for now. If one of my 430s packs up, then it’s a no-brainer. But as long as that doesn’t happen…no.
LPV utility depends on where you fly.
Many pilots, myself included, find most relevant airports have ILS.
ILS remains the gold standard in Europe for commercial ops.
Doubtless this conversation will be different 5 or 10 years from now.
Also as pointed out above, LPV upgrade has huge knock on effects for many people, making it a big job, expensive, and severely limiting on which shops can do it well. For example a GNS or GTN box is not fully compatible with the King MFDs… Very few people know this because it shows up only in the OBS mode which most pilots don’t know. So a lot of kit needs ripping out.
A 4 or 5 yo 430W is not a “very old piece of HW”, and it does everything an IFD or GTN does, just with a little less comfort. It also does not matter how old the design is of the unit does what i need, and it does LPV, LNAV/VNAV and LNAV+V with perfection,
I am not flying to England much, Germany and France and have LPV at every relevant airport.
I sold two 430s for 8000 and bought two W units with 200 h TT for 13.500.
(I am not a commercial operator, and I think LPV is the much better and safer technology for private pilots).
One thing that many forget/don’t know: With a 430W you can fly a normal LNAV approach with a virtual glideslope because Garmin provides the “LNAV+V” feature for those. I am not sure if this is true for all LNAV approaches, but the ones I tried all had it.
The LNAV+V can also be flown coupled and while the LNAV minima apply the precisison is still very high.