Date: 201703
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Aircraft component: PMC; Performance/Thrust Management Computer
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Situational Awareness
Second reporter function: Pilot Not Flying; Captain
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: Taxi
Result: Flight Crew Became Reoriented; Flight Crew Returned To Gate; General Flight Cancelled / Delayed
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: Due to an error on my part; our flight returned to the gate unnecessarily. The flight was delayed. As the First Officer I had transcribed the ATIS temperature incorrectly as +6 Celsius instead of -6 Celsius. I entered this incorrect data into ACARS and sent off for performance numbers. When the numbers came back we entered them into the MCDU. We taxied out and after the taxi checklist was started we saw an EICAS message of 'engine data no takeoff'. We set the brake and ran through the performance data; resent for numbers; but the EICAS message kept reappearing. The Captain called maintenance who advised him to return to the gate. We taxied back to the gate. As we waited for maintenance I picked up the new ATIS and saw my error. I informed the Captain that I had written down the wrong temperature and that the error was my fault. Maintenance showed up. We confessed. Captain voided the entry in the logbook; we got more fuel and departed.This could have been avoided several times. I knew that it was below freezing when I'd arrived the night before and yet I wrote down plus 6. I should have been slower and more deliberate while reading the digital ATIS. Although no one was deicing not only did I notice deicing trucks lurking about; but on my preflight; I saw that the horizontal stab was 2 degrees nose down. I'd also checked the wings for frost and informed the Captain that the wings were clean.Self-doubt goes a long way and I hope that this error will; in the future; linger with me; nagging me to be more vigilant.


Second narrative: Today's flight resulted in a controllable delay through a return to gate situation; was easily preventable. After an on time push-back/engine start we completed the after start checklist and proceeded to the departure runway on one engine.During our taxi I asked the First Officer to start the second engine and completed the taxi checklist. As we approached the departure end of the runway we received the EICAS message 'engine data no takeoff.' While holding short of the runway we notified ATC we needed time to troubleshoot an issues and were given permission to remain in our current position. Both the First Officer and I began digging through the FMS to see if we could find what was causing this message; each time we re-entered information the message would reappear. Puzzled at our predicament I took a minute to make an announcement to the passengers; then contacting Dispatch and Maintenance. After approximately ten minutes on the phone with Maintenance a solution could not be found so we elected to return to the gate where maintenance personnel would be waiting. I again kept the passengers and cabin crew informed and we received permission to taxi back to our original gate. Once we parked at the gate; just prior to the mechanics boarding the aircraft we discovered our self-inflicted error.This morning's temperature was in the single digits; while initially setting the takeoff data after the single engine start I entered the temperature from the ACARS data page. This allowed me to input a positive temperature into the Thrust Reference System (TRS) when it was actually a negative temperature outside. The data had originally been requested without catching the error; led us down the wrong path we headed. I kept looking through our ACARS and TRS pages trying to figure out what we had entered incorrectly; but it wasn't till a new ATIS was requested and we both saw the temperature was in fact supposed to be negative and not positive. This was a completely preventable; sophomoric error for which I take full responsibility. While the aircraft never entered an unsafe aircraft state; this error/delay had down line implications for the aircraft; passengers and crew.Always verify the data against the current ATIS; not just the aero data that was sent/received. I must also do a better job of encouraging my fellow pilots to write out the ATIS/clearance in large; legible print and leave it visible from both pilots; this was not that case today; my First Officer had it out for viewing. I have grown frustrated and complacent as more and more First Officers write this down and then proceed to hide it on their side of the flight deck; I need to speak out more. I must also be more vigilant as my recency of experience wains; while on reserve I have not been flying as often and fear I will overlook things like this.


Synopsis: EMB175 flight crew reported entering the incorrect temperature in the performance data; resulting in an EICAS message of 'engine data no takeoff'. After a return to the gate; the error was discovered.