[Username Protected]

Has anyone ever gotten CAS message "PTRIM NML FAIL" inflight along with a corresponding loss of auto pilot? Ironically everything worked fine on the next flight but now I am wondering why it happened and if it will happen again.

[Username Protected]

Has anyone ever gotten CAS message "PTRIM NML FAIL" inflight along with a corresponding loss of auto pilot? Ironically everything worked fine on the next flight but now I am wondering why it happened and if it will happen again.

(Username Protected),
Yes-seen it.
actuator changed. Then, TAC changed.
Then, GIA 1 changed.
it was found to be a problem related to software upload after FMS replacement.
yours could be any of above, starting with the first one above? Or something else altogether.
My experience is a case study of one.
Good Luck and let us know what you find.

[Username Protected]

I have also seen it after my plane was cold-soaked outside in Aspen in the winter. Never recurred. I assume the avionics were just unhappy being so cold.

[Username Protected]

We are troubleshooting this now in my Phenom 100. The symptoms are:

- at some point in the flight, PTRIM NML FAIL. At some point later, sometimes you also get an A/P PITCH MISTRIM with loss of autopilot for the rest of the flight. Originally we thought this only happened in the flight levels, but Tom Norton and I experienced it yesterday at 2,000 ft on a short local flight in Florida. (i.e. it isn't likely caused by cold soak)

- doesn't occur on every flight (intermittent)

- when it does occur, the backup pitch trim works to retrim the airplane

- after shutting down when it occurs, on the next reboot of the plane BOTH pitch channels fail to work (normal and backup), however there is now NO CAS. Continuing to reboot the plane doesn't fix it. Cycling both circuit breakers doesn't fix it.

- after waiting another 30-60 minutes, everything works fine

- additionally on one flight I also got a NO TAKEOFF red CAS and the voice said "no takeoff, trim", yet the visually displayed trim looked correct. The yoke trim switch was able to move trim up and down and back into the green range, and despite several cycling of the trim in and out of the range (using the yoke switch), the NO TAKEOFF CAS did not clear. After powering off the airplane and waiting 30 minutes, everything worked fine.

We have have already replaced the left actuator and controller and the issue is still occurring. Plan now is to replace the right actuator and see what happens. Big thanks to Chris Grinnell and Tom Norton for help with troubleshooting and to Chris for squeezing us in to his busy busy facility.

[Username Protected]

We are troubleshooting this now in my Phenom 100. The symptoms are:

- at some point in the flight, PTRIM NML FAIL. At some point later, sometimes you also get an A/P PITCH MISTRIM with loss of autopilot for the rest of the flight. Originally we thought this only happened in the flight levels, but Tom Norton and I experienced it yesterday at 2,000 ft on a short local flight in Florida. (i.e. it isn't likely caused by cold soak)

- doesn't occur on every flight (intermittent)

- when it does occur, the backup pitch trim works to retrim the airplane

- after shutting down when it occurs, on the next reboot of the plane BOTH pitch channels fail to work (normal and backup), however there is now NO CAS. Continuing to reboot the plane doesn't fix it. Cycling both circuit breakers doesn't fix it.

- after waiting another 30-60 minutes, everything works fine

- additionally on one flight I also got a NO TAKEOFF red CAS and the voice said "no takeoff, trim", yet the visually displayed trim looked correct. The yoke trim switch was able to move trim up and down and back into the green range, and despite several cycling of the trim in and out of the range (using the yoke switch), the NO TAKEOFF CAS did not clear. After powering off the airplane and waiting 30 minutes, everything worked fine.

We have have already replaced the left actuator and controller and the issue is still occurring. Plan now is to replace the right actuator and see what happens. Big thanks to Chris Grinnell and Tom Norton for help with troubleshooting and to Chris for squeezing us in to his busy busy facility.

(Username Protected)
sent you a private message!
Good luck! If anyone can figure it out, Chris can!