[Username Protected]

At EOC'23 Embraer shared that they have identified the root cause for spurious CAS PTRIM NML FAIL or CAS PTRIM BKP FAIL messages on the P300.

"PTA position sensor can potentially introduce noise to the position reading resulting in an uncommanded motion monitor trigger. The FCE can interpret the potentiometer noise as a PTA motion and active the uncommanded motion monitor.


A filter was added to the position signal decreasing noise effects. A capacitor was connected to the potentiometer wiper in aircraft harness."


Parts are free of charge for 36 months. The SB is SB505-27-0030.

[Username Protected]

At EOC'23 Embraer shared that they have identified the root cause for spurious CAS PTRIM ML FAIL or CAS PTRIM BKP FAIL messages on the P300.

Thanks for posting this (Username Protected). It happened to me at 450. Had to land no flaps. Nice to see the fix.