WIth ten weeks to go before I pick up my SR 22, I am caught in the ARNAV vs. Avidyne decision. Having seen the Avidyne at AOPA Expo and seeing their full line of products, it seems that Avidyne has better future prospects than Arnav. They sell to more types of aircraft, whereas Arnav seems to be focused mostly on Cirrus. With that in mind, I am leaning towards the Avidyne. However, engine monitoring is something that everyone seems to agree is virtually a “must have.” Like others, I have been told by Avidyne that they will develop engine monitoring if Cirrus asks them to. But, if Cirrus is going with FADEC later this year, it also seems that Cirrus may feel there is little reason for Avidyne (apparently their choice for display provider of the future) to develop the monitoring system for the relatively few planes which would be built before FADEC becomes available.
I would appreciate anyone’s thoughts on this subject. Are there other aftermarket engine monitoring systems out there which could run through the Avidyne display, or would such a system require a panel mod. for its display? Also, has anyone installed another monitoring system on a Cirrus to date?

Great question. I’m in the identical quandry. It’s especially difficult as we don’t know how practical it will be to add Fadec after delivery.


I have had my SR22 for 6 weeks. The ARNAV engine monitoring is great…as for FADEC, I am not yet sold on it, especially if it does not allow for LOP operation. I flew back from Chicago to PA last evening at 9000 feet. TAS was 179kts at 13.6gph. ROP would have put me at 17gph and around 185kts. The ARNAV engine monitoring has worked beyond my expectations. The only thing that I would really like to see on the ARNAV or AVIDYNE display would be approach plates. Otherwise, I just have no complaints.


I suggest going with Arnav for two basic reasons:

  1. Engine monitoring is useful, even with FADEC. It can warn you about problems with your engine and give you an aid to diagnosing problems earlier than you might know about them otherwise.

  2. There will always be something cooler on the horizon. Avidyne and FADEC cool, and on the horizon. But FADEC isn’t available in the SR22 yet. And Avidyne doesn’t do engine monitoring yet. I don’t think anyone really knows whether they are six months away, two years away, or will never do it for lack of demand. I suggest going with the tried and true.

I’m pretty happy with the Arnav after a lot of initial hassle, and I’m very glad that Avidyne has put the scare into Arnav – maybe we’ll get some big improvements, like finer grain terrain awareness, in a few months (as promised).

I have found Arnav customer service to be excellent.

Spoke with Bruce Gunther at Cirrus who indicated that the arrangement that Cirrus has with Avidyne anticipates the offering of engine management and approach chart display later this year irrespective of if or when FADEC is offered. Based on that, I will take delivery in March with the Avidyne unit. He believes that FADEC is not imminent.

Having visited the Arnav factory lately and seen the great strides that they are taking in the next release for the ICDS2000, I would rethink any decision about avoiding the Arnav Display. I had the chance to see first hand how well the new release works that I am looking forward to being able to fly it. I have a Cessna 180 with the ICDS2000 and also the Engine Trend Monitor/Recorder and also understand that Arnav is installing the ICDS2000 in several other aircraft in the near future as well. All I know for sure is that I am glad that I went with the Arnav Display System.

Don’t be so quick to discount the ARNAV display. It seems to be much more readable-visible in bright SUNLIGHT. Am I the only one who has noticed this? That is very important to me.

I have installed a JPI 800 engine monitor in my SR20 and now in my SR22. It works perfectly and is cheaper and better than the RNAV. Why put information on the big screen when it can be readily displayed elsewhere. In case my email comes through wrong it is - gclewis77@msn.com

Does anyone know when Fadec will be available? Mike

FADEC will run lean of peak when running at less than 75% power. This is per Aerosance.

Paul, I couldn’t agree more. While I would love the ability to display a full approach plate on the MFD I too find the ARNAV more than adequate. The engine monitoring is really wonderful. The ability to see all the temps digitally and simultaneously is very helpful. The ability to run LOP I agree is almost necessary for good range. I too find I can get another 7-10 KTAS at “best power mixture” at the expense of 3-4 extra GPH.
Jerry N1970

I am not so sure I will want to pay for approach charts on either the ARNAV or the Avidyne. It will probably cost at least $700-800 per year and I am willing to hold the darn things in my hand or on the kneeboard for that much. I don’t believe the approach chart overlay will add that much to the situational awareness we have now. I subscribe to vRotate for my approach charts and low altitude enroute charts for about $120/year. This covers the Southeast only, but I do not go other places that much, and if I do, I can get what I need a la carte from the FBO. Right now, the monthly update for the Garmins is getting done on an ‘as needed’ basis, not monthly. Between the Garmin updates, the Sandel HSI, and the ARNAV, you could spend $1,000/year. Add a subscription to approach plates for the MFD and I believe you may total almost $2,000/year. Another question remains, will this satisfy the FAA requirements for ‘all materials necessary for a safe flight’? In other words, can you legally file IFR with no paper charts with the approach plate database in the MFD? If you can do it legally, will you?
My two cents.

Did you install it in the bolster below the switches like you did in the 20? Do you have a photo? You can use the new photo attachment feature of the forum to show it to us if you have one.

Does the JPI 800 include a fuel flow / fuel remaining / fuel to destination computation as well?


Greg, I want to reply to your question about the legality of filing IFR without paper charts. Even without a GPS database there is NOTHING in the FARs to require you to have approach charts in the airplane. What you MUST have is all the information needed to fly any instrument approach you may need to fly. If you were to copy the localizer frequency, OM crossing altitude, DH and missed approach procedure onto a piece of paper your would have the required information for that approach. You could also commit it to memory. It would be nice also to know the MSAs, frequencies etc. but you don’t need the official chart on board. The database does NOT give you all the information you need in that there is no vertical information (at least not yet).
Please note that I’m not suggesting it is a good idea to fly IFR without the appropriate charts. I’m only saying it’s legal as long as you have all the information. In practice the easiest way to do that of course is simply to have the chart, but other methods are also acceptable.

Thanks for the info, it’s good to know. However, as you said, as a matter of practice, I doubt many of us are willing to fly without at least some visual representation of the approach. Also, I would want to be able to make an unscheduled instrument approach anywhere enroute for any possible aircraft emergency, icing level getting too low for MEAs, unexpectedly strong headwinds leading to an unplanned fuel stop, etc. But, I can tell you probably feel the same way and you probably do not actually embark on IFR flights with such minimal information. So, as a practical matter, does the approach plate on an MFD really seem that beneficial to you? Admittedly, the ‘Gee Whiz’ factor is really high, and you’ve 'gotta love that.

Greg, first off, in a real emergency where you have to get down and don’t have the plate the controller can and will give you whatever information you need. That’s an excellent backup too many pilots don’t consider. But it should only be a service you request for a real emergency.
Regarding the approach plate on the MFD, I personally would love having it. Currently I use JeppView. I print the charts I plan to use on a given flight (including several alternates) and then carry my lap top just in case I need others. If I could view the data on JeppView on a MFD it would be far preferable to lugging the laptop. It also would mean that the actual graphic chart will be instantly available for any airport if needed. To me that’s worth it.

I agree with you on both counts. The only problem is one I expect to run into this month. I am flying from GAI to MHK with a fuel stop at FRH. Going is not a problem, but I expect my GNS430 update to arrive the day the old data base expires and I will be in MHK at the time. So on the way back my database will not be current and without an NDB there is no approach I can legally use at FRH. What we really need is the ability to download updates automatically from satellite.

Another solution would be to have the database available about (5) days before expiration of the old one so that you could at least have a window of opportunity. It would even be better if the Garmin could hold both the old and the new databases simultaneously and switch to the new one when appropriate.
The ultimate solution would be ‘real time’ downloads via satellite, though. If that is what you were referring to, agreed. Then we could forget about maintaining a database on the unit completely.

Art, the problem with expiration dates is a real one. The database is ready for downloading at least several days before the end of the cycle and one solution is to program one card in advance of your trip and use it in the #2 Garmin until the effective date (it will work before or after the database period) then switch it to #1 on the effective date. Get the approach from #1.
The other solution is the easy one for me. Since I carry my laptop with me wherever I fly (to have all the approach charts), I can download the new data cards anywhere. Still, I wish there were a better, easier way.
By the way how’s everything at GAI. I got my instrument and multiengine ratings there in 1970 while I was in the Navy stationed in Bethesda. My first home after I got married was in Gaithersburg as well. Very fond memories.