The first officer of an embraer EMB175 reported that they aborted takeoff because the throttles were...

Narrative:

The captain was pilot flying. Once cleared onto runway for takeoff; we were taxiing into position; and while making the turn to centerline; the engines were spooled up to about 40% N1. The captain then adjusted his body position in his seat; inadvertently pushing the thrust levers past the position where the auto-throttles engaged; powering the engines up to full takeoff power; before we were completely lined up on centerline. This forced us through centerline and aimed towards the grass between taxiways 'X' and 'X1'. Immediately pulling the power back to idle; the captain regained control and steered back to centerline. We then exited the runway at 'X1' which was about 1;000 feet from where we entered onto the runway; taxied back to runway; ran the before takeoff checklist and departed.waiting until completely lined up on runway centerline before spooling the engines up past idle thrust. An additional measure that would have prevented this from happening is waiting until lined up on runway before arming the auto-throttle.

Original NASA ASRS Text

Title: The First Officer of an Embraer EMB175 reported that they aborted takeoff because the throttles were inadvertently pushed past auto-throttle position for takeoff.

Narrative: The Captain was pilot flying. Once cleared onto runway for takeoff; we were taxiing into position; and while making the turn to centerline; the engines were spooled up to about 40% N1. The Captain then adjusted his body position in his seat; inadvertently pushing the thrust levers past the position where the auto-throttles engaged; powering the engines up to full takeoff power; before we were completely lined up on centerline. This forced us through centerline and aimed towards the grass between taxiways 'X' and 'X1'. Immediately pulling the power back to idle; the Captain regained control and steered back to centerline. We then exited the runway at 'X1' which was about 1;000 feet from where we entered onto the runway; taxied back to runway; ran the before takeoff checklist and departed.Waiting until completely lined up on runway centerline before spooling the engines up past idle thrust. An additional measure that would have prevented this from happening is waiting until lined up on runway before arming the auto-throttle.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1434821
Time
Date	201703
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	EMB ERJ 170/175 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural Published Material / Policy Ground Event / Encounter Loss Of Aircraft Control

The first officer of an embraer EMB175 reported that they aborted takeoff because the throttles were inadvertently pushed past auto-throttle position for takeoff.