Date: 201512
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Elevator Trim System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Departure Airport
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We had a maintenance delay for wing anti-ice failure in flight on our previous leg. While the maintenance personnel had the logbook and were completing the write-up for the anti-ice fix; I checked my pitch trim and received a MAIN PTRIM INOP EICAS message. I notified the maintenance crew; and they performed a reset (later determined to be a 'partial' reset). I tested my pitch trim; and it worked. They returned the logbook; we boarded; and took off. Right away on the initial climb; I realized I was unable to trim. At about 500 feet; we got a MAIN PTRIM INOP EICAS message. We continued to climb and follow the departure. I pulled back power partially; but the trim was stuck at about 7 up. The Captain (CA) tried the backup trim; but it failed as well. At some point shortly after; we were able to use the backup trim partially again and were able to trim to 6 up and eventually 5 up on landing. The CA [requested priority handling] and requested a return. He took the aircraft. We attempted to run the checklist; but given the workload and situation (the CA at points had to use considerable strength to maintain altitude); we agreed to forgo the checklist to get on the ground ASAP. We got landing data for flaps 45; but on final we decided to land with flaps 22 since the aircraft was easily controllable in that configuration. Also being familiar with the airport; we knew that flaps 22 would be acceptable. We didn't get new landing data for flaps 22 since we were on short final; but we did increase Vref and Vapp by 5 knots. We landed and returned to the gate. Also; because of the workload; the FA was notified; but neither the CA or I spoke to the passengers until we were on the ground. On the taxi in; I notified Operations and maintenance personnel and quickly returned to the plane. We deplaned the passengers; and Maintenance performed a 'full' reset and declared the aircraft good to go. The CA and I agreed that we were uncomfortable flying the aircraft despite the reset; and eventually we were given a new aircraft and continued on to [destination] without incident.Obviously having little control over pitch trim is an undesired aircraft state. The threats included: night conditions; heavily saturated airspace (we got a TA at one point) and poorly trained maintenance personnel. The errors included: not speaking to the passengers during the [event]; not completing the QRH; not sending landing data for flaps 22.The CA and I exited the cockpit when the maintenance crew performed the initial reset on the pitch trim. I wasn't watching; but the CA was; and he said he didn't think the maintenance crew did the reset correctly. He said they didn't seem to know what they were doing (a backup maintenance person had to be called); and they didn't reset any circuit breakers behind the CA seat; which the CA said he thought was normal protocol. Because the trim worked and the maintenance crew said everything was good after the reset; we continued. So; I would like to see better trained maintenance personnel.All things considered; the CA and I had good CRM; we were familiar with airport and the aircraft; and we had good situational awareness. Largely because of all these things; we were able to land safely despite the emergency.




Synopsis: Embraer Regional Jet crew has a main pitch trim failure on departure. Crew returns to departure airport with reduced flap setting.