Originally Posted by
Vilters
What I don't understand (well I do because building airplanes is all about keeping the costs down) is why they keep using these "obsolete" and fragile vane sensors.
Back in 1979 when we first got the F-16's we where all too happy to see "new" differential pressure activated AOA sensors. => But => But => And that is where it all goes dark => They are more expensive.
The reason they use them is that they are simple and they work. A 737 takes off or lands somewhere in the world every 3 seconds or so, if these AoA vanes had any unreliability it would be very very obvious and
there is no such failure rate. So almost certainly it is not the AoA vanes. As stated upthread there may be some reason for the Max failure rate that is to do with wiring or perhaps location of the engines, But this will not be simple to find as there have been many many 737Max flights and a simple design fault such as engine location or broken look up tables in software would have become very obvious in every Max - it hasn't.