EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Aircraft
Approximately 20 minutes into the flight; during climb at approximately 16;000 feet; the first indication of an issue is when the autopilot failed.  We heard the warning and saw the EICAS message at which time I manually took control of the aircraft.  The captain; who was the pilot not flying; took out the QRH and started to go through the checklist for the autopilot failure.  At this point we got the either the backup pitch trim INOP or the main pitch trim INOP; at which time the captain pressed the quick disconnect button. I do not remember which message came first; but as the captain started to run the checklist for the first pitch trim message the second one came through.  The weather was deteriorating as we got farther north so we informed ATC we need to turn towards better weather and they gave us a turn to heading 180 and a climb; and we notified them we needed to stop at FL290 in order to not enter RVSM airspace. I continued to just fly the airplane which felt normal to me in terms of control pressures and response as the captain ran all of the checklists.  At this point he decided to [divert] and we were informed that the nearest airport with good weather was only 63 miles away.  We received a clearance to go there and he continued to run the checklists.  I started the descent per the ATC clearance at 1000 FPM.  As I started to slow from 240 KIAS to approximately 210 KIAS I noticed that the nose down tendency was getting greater requiring more back pressure to maintain the 1000 FPM descent and I discussed this with the captain.  After passing FL290 we put in flaps 9 and this relieved some of the pressure.  He ran all of the QRH procedures up to the point of the approach and landing checks and set up everything for the approach.  The captain notified the Flight Attendant that we were having an issue but that everything was under control.  She was notified that she needed to put everything away and be seated.  We discussed the likelihood of the nose down tendency becoming greater and back pressure required to overcome it as we slowed to approach speed and decided it was better for the captain to take the landing.  Prior to receiving vectors for the approach we switched roles and he took the controls and I took the QRH.  The approach itself was uneventful.  We added the flaps 18 first; got a feel for what changed in terms of control pressures; then flaps 22.  Per the QHR; we waited to lower the landing gear.  I finished the landing checklist and at approximately 200 feet AGL informed the captain I would have my hands on the yoke in case he needed any assistance.  The landing itself was very smooth and he did not need my help.  We rolled out and made the turn onto taxiway A from runway and taxied to the gate with no issues. At no point was the aircraft uncontrollable.  We made sure at all times that one of us was solely focused on flying the aircraft.  I feel we worked together very well and the outcome was what we had wanted it to be. We are always trained to have one person fly the aircraft at all times and the importance of crew communication.  I believe that we executed everything the way it needed to be done and that resulted in a safe landing.
EMB-145 flight crew received pitch trim warnings and experienced related elevator control anomalies. Crew diverted to a nearby airport without incident.