Is there anyone here making use of their FEVA engine monitor data analysis, which seeks to predict exhaust valve failure?
There is an interesting article by Savvy in the last US AOPA mag. Their original software, a few years ago, just looked for a periodic EGT fluctuation, around 1 cycle per minute. This picked up loads of cases but they have since found that an improved machine learning program picks up a lot more. The issue they now have is that they cannot tell how it is detecting them!
I’ve been using their service for one year now. The FEVA isn’t as useful since I have a new engine (200 hours so far) and I fly using Savvy’s YouTube video guidelines (very lean of peak but keeping CHTs above 300), but the engine monitor analysis is very useful. During test flights they’ve been able to diagnose things even as minor as one of my spark plugs being gapped wrong.
I use it; I had a few emails with them on their model, since they use an LGBM they could use Shapley values to explain the drivers of the prediction. Since 2019 you’ve had freely available Python packages allowing you to do this and display really cool charts.
But doing so would expose their intellectual property (knowing the features of a model is half the battle in my experience), and given how innovative/aggressive the other company (Garmin) with as much data as they have is, they’re probably right to want it protect it.
I have subscribed to the service, and I find it very interesting. My FEVA reports thankfully come in all green, below average risk, etc. since I also have a new engine. As someone who likes to “play” with “big data”, I can imagine that their dataset must be a gold mine of things we don’t yet know about engines.
I used to subscribe to Savvy and I was hoping to use their “report cards” which compare your model to others of the same type. At the time, as my EDM was set to record in litres (as I buy my fuel in litres) they could not give me a report card to compare to other similar PA28’s . Very disappointing.
That lack of flexibility meant I did not renew my subscription.
The FEVA looks interesting but I Borescope every 25 hours
Mike Bush had a webinar a few weeks ago on the new FEVA2 logic.
their conclusion was that a valve predicted by the model to have “above average proability” of failure, turned out 1 in 4 chance of actually being a failure.
I’d not rely only on their FEVA logic but if the algorithm indicates any risk, i’d definitely go ahead with the boroscope inspection.
I guess it is not exactly cheap; people won’t pay for this unless there are clear benefits
and with a European-reg plane you have the extra dimension where Savvy might be seen as conflicting with the local shop.
And a borescope is so cheap nowadays that there is no excuse for not borescoping the valves at every service, and I don’t suppose most people download engine data more often than that. Actually I would bet most people never download their engine data 
Hi Archer-181 I have an EDM830 in my Archer-181 it might be interesting to swap info – you can email me
Peter wrote:
I don’t suppose most people download engine data more often than that. Actually, I would bet most people never download their engine data
I am paying for the $129 subscription to get the professional analysts, but I suspect I fly a lot compared to other GA owners. Typically 100 to 200 hours a year, since I use it as my business commuter. I’m also still building and changing things on my plane, so it’s good to have comparisons and have someone check for issues (things like vortex generators around cooling vents for extra cooling, next week installing E-Mags, etc). So I download all my flights and upload them to Savvy. Sometimes not after every flight, since my unit can store about 22 hours of flight info, but I try to get as much to them as possible. And I also boroscope at every annual.
I guess for normal flyers flying normal cert GA aircraft, it won’t be as useful other than to kee track of trends to catch things if the engine starts acting up.
