Originally Posted by
Duffman
About that... thanks to Ligado a 5G freq will be running dangerously close to the GPS band shortly.
The much stronger L1C and L5 signals will negate those concerns in a decade or so.
Originally Posted by
pangolin
I don’t know if it’s the AC system or the ground signal or too many too close but the LOC will capture and start down on the glide slope with a full scale deflection when it is clearly not captured properly. Arming appc mode “too soon” is contributory. Check ASAP reports. There’s a significant number of these.
That’s probably the biggest contributor. Newer systems do a rationality check with the FMS position but older ones are notorious for capturing nothing especially with the long finals and non-standard intercept vectors common at ‘busy’ airports.