Narrative:

When the crew arrived at [the aircraft]; maintenance control had deferred the ground idle portion of the eec's (electronic engine control). Myself as the captain looked over the ddg (dispatch deviation guide); talked with the two mechanics on board and found that everything was written off properly. The mechanic and I discussed the ramifications a little bit on the referral. The plane blocked out on time with a normal engine start and normal taxi to [the] runway. However upon takeoff clearance and bringing the thrust levers up to approximately 70% we noticed the right engine was accelerating quicker than the left engine. It wasn't exceeding any limitations but still as the captain and because we had the deferral concerning the situation ; I felt it would be better/ conservative to just bring the thrust levers back and taxi off the runway and discuss what was actually going on with the mechanics in a safe environment on the taxiway and that is what I did. I asked the first officer to cancel takeoff clearance and that we would like to clear the runway and discuss a possible maintenance issue. So we cleared the runway; I spoke to the mechanics about the situation and it is quite common on most of the 767 200s for the right engine to accelerate quicker than the left engine. I don't know why this is but I've noticed it on many different airplanes. So we cleared the runway.I spoke to the mechanics about the situation. I remembered talking to maintenance control the day before and he informed me there are no time limits for the engines to accelerate together. At this moment on the taxiway I confirm that with the two mechanics that only the two engines had to match and then accelerate uniformly after takeoff thrust button was pushed and takeoff power is set. After clearing the runway there were no checklists to be run since there are no EICAS messages or abnormal events. I just wanted to understand that everything was fairly normal. The break chart was not needed to be consulted since we never really release the brakes for takeoff. Takeoff power was never set. By definition in the fom a rejected takeoff was never really performed since take off power was never set however I am going to treat this like a rejected takeoff just in case. The two mechanics and the first officer and myself discussed that we would perform the takeoff again.... Let the engines both stabilize at approximately 70% and then push the takeoff thrust button and if the engines accelerated absolutely perfectly symmetrically to takeoff thrust then we would continue the takeoff. This is exactly what happened on the second takeoff and this is normally what happens on most of the 767 200s. The engines do not accelerate to 70% symmetrically all the time but they do accelerate from 70%to takeoff thrust symmetrically. Maintenance control and the mechanics confirmed there is no time limit to where these engines have to accelerate to the 70% setting. The takeoff was normal.

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Original NASA ASRS Text

Title: Captain reported a rejected takeoff after number 2 engine acceleration lagged significantly.

Narrative: When the crew arrived at [the aircraft]; Maintenance Control had deferred the ground idle portion of the EEC's (Electronic Engine Control). Myself as the Captain looked over the DDG (Dispatch Deviation Guide); talked with the two mechanics on board and found that everything was written off properly. The Mechanic and I discussed the ramifications a little bit on the referral. The plane blocked out on time with a normal engine start and normal taxi to [the] runway. However upon takeoff clearance and bringing the thrust levers up to approximately 70% we noticed the right engine was accelerating quicker than the left engine. It wasn't exceeding any limitations but still as the Captain and because we had the deferral concerning the situation ; I felt it would be better/ conservative to just bring the thrust levers back and taxi off the runway and discuss what was actually going on with the mechanics in a safe environment on the taxiway and that is what I did. I asked the First Officer to cancel takeoff clearance and that we would like to clear the runway and discuss a possible maintenance issue. So we cleared the runway; I spoke to the mechanics about the situation and it is quite common on most of the 767 200s for the right engine to accelerate quicker than the left engine. I don't know why this is but I've noticed it on many different airplanes. So we cleared the runway.I spoke to the mechanics about the situation. I remembered talking to Maintenance Control the day before and he informed me there are no time limits for the engines to accelerate together. At this moment on the taxiway I confirm that with the two mechanics that only the two engines had to match and then accelerate uniformly after takeoff thrust button was pushed and takeoff power is set. After clearing the runway there were no checklists to be run since there are no EICAS messages or abnormal events. I just wanted to understand that everything was fairly normal. The break chart was not needed to be consulted since we never really release the brakes for takeoff. Takeoff power was never set. By definition in the FOM a rejected takeoff was never really performed since take off power was never set however I am going to treat this like a rejected takeoff just in case. The two mechanics and the First Officer and myself discussed that we would perform the takeoff again.... let the engines both stabilize at approximately 70% and then push the takeoff thrust button and if the engines accelerated absolutely perfectly symmetrically to takeoff thrust then we would continue the takeoff. This is exactly what happened on the second takeoff and this is normally what happens on most of the 767 200s. The engines do not accelerate to 70% symmetrically all the time but they do accelerate from 70%to takeoff thrust symmetrically. Maintenance Control and the mechanics confirmed there is no time limit to where these engines have to accelerate to the 70% setting. The takeoff was normal.

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.