Narrative:

Upon push back off gate first officer started the right engine and then the left. Before we had a chance to run after start checklist I noticed a split of N2 gauges greater than 2%; 2.3 to be exact. [I] asked first officer if he concurred. Ran flow for checklist; and then pulled out manual to verify limitation on engine start of no greater than 2% N2 split for engine start. Called maintenance control to see if any action could be taken to correct problem or should we contact dispatch and return to gate. He had never heard of the limitation and seemed puzzled by the question. At that point I read our limitation to him out of the manual. He instructed me to turn off the speed switches; and then turn them back on. [He] asked if that solved the problem. It brought the N2 split to 1.8-1.9 %. Told of the outcome; asked if I was fine with that. At that time I told him the question is up to him. I was reading normal indications; and if I see any problems I will bring it back to the gate or write it up on landing. We see N2 splits close to these limitations all the time on the line; the only thing that was abnormal was the initial 2% N2 split. All itt; vibration; fuel flow; and percentages were normal. Upon thrust lever advancement for takeoff there was a lag in the left engine spoil up. On write up was told I had to give a time of lag; estimated it to be around 1.5 seconds. That might seem to be a lot; but in all actuality that is pretty standard for the crj fleet we fly. I have seen a heck of a lot worse as far as spoil up time split on the fleet we currently fly. Anyway we hold the brakes until about 75% N1 per fom to avoid takeoff warnings and asymmetrical thrust leading to directional problems. As pilot in command I saw no indications of engine malfunction or thrust output problems leading me to cause an abort or a gate return. If I return to the gate for split thrust spool ups I would return to the gate more than 50% of the flights I fly. The real problem was with the split on approach. The split was a real nuisance. More time had to be given to the thrust levers during IMC operation. This was when the decision was made to write it up. In the write up I include split thrust and lag on take off application and during flight; to help the maintenance folks diagnose the problem. To show it was in all phases of flight. Once at the gate I called maintenance control and told them it was more of a pain in the butt to fly than anything else. [They] asked me if I turned off the speed switches. Told them no!!! That's a maintenance function!!! I don't just turn off switches in flight. The only time I will is if told to do so by the QRH; but there were no indications of an overspeed or any other malfunction that would cause me to run a QRH. Split thrust and lag in engine spoil up are common on flights. At no time did either engine show any indications other than normal after thrust lever advancement during this flight. I believe in the future I will gate return for the N2 split; and let mechanics diagnose the problem. Hopefully they would have found the problem. Also I will gate return for at the first indication of split and a lag in engine spoil up on thrust lever advancement for takeoff. I believe we have a great procedure of holding the brakes until 75% on both engines for takeoff. It is what counteracts this problem. Also looking down the line at weather is important; if it is going to be IMC or contaminated runways I will lower my threshold of what is acceptable for aircraft quirks which sometimes as pilots we feel are normal.

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Original NASA ASRS Text

Title: CRJ200 Captain experiences engine anomalies after start up; during takeoff; and during approach which are written up upon landing. The reasons for not returning to the gate are explained.

Narrative: Upon push back off gate First Officer started the right engine and then the left. Before we had a chance to run after start checklist I noticed a split of N2 gauges greater than 2%; 2.3 to be exact. [I] asked First Officer if he concurred. Ran flow for checklist; and then pulled out manual to verify limitation on engine start of no greater than 2% N2 split for engine start. Called Maintenance Control to see if any action could be taken to correct problem or should we contact Dispatch and return to gate. He had never heard of the limitation and seemed puzzled by the question. At that point I read our limitation to him out of the manual. He instructed me to turn off the speed switches; and then turn them back on. [He] asked if that solved the problem. It brought the N2 split to 1.8-1.9 %. Told of the outcome; asked if I was fine with that. At that time I told him the question is up to him. I was reading normal indications; and if I see any problems I will bring it back to the gate or write it up on landing. We see N2 splits close to these limitations all the time on the line; the only thing that was abnormal was the initial 2% N2 split. All ITT; vibration; fuel flow; and percentages were normal. Upon thrust lever advancement for takeoff there was a lag in the left engine spoil up. On write up was told I had to give a time of lag; estimated it to be around 1.5 seconds. That might seem to be a lot; but in all actuality that is pretty standard for the CRJ fleet we fly. I have seen a heck of a lot worse as far as spoil up time split on the fleet we currently fly. Anyway we hold the brakes until about 75% N1 per FOM to avoid takeoff warnings and asymmetrical thrust leading to directional problems. As pilot in command I saw no indications of engine malfunction or thrust output problems leading me to cause an abort or a gate return. If I return to the gate for split thrust spool ups I would return to the gate more than 50% of the flights I fly. The real problem was with the split on approach. The split was a real nuisance. More time had to be given to the thrust levers during IMC operation. This was when the decision was made to write it up. In the write up I include split thrust and lag on take off application and during flight; to help the maintenance folks diagnose the problem. To show it was in all phases of flight. Once at the gate I called Maintenance Control and told them it was more of a pain in the butt to fly than anything else. [They] asked me if I turned off the speed switches. Told them NO!!! That's a Maintenance function!!! I don't just turn off switches in flight. The only time I will is if told to do so by the QRH; but there were no indications of an overspeed or any other malfunction that would cause me to run a QRH. Split thrust and lag in engine spoil up are common on flights. At no time did either engine show any indications other than normal after thrust lever advancement during this flight. I believe in the future I will gate return for the N2 split; and let mechanics diagnose the problem. Hopefully they would have found the problem. Also I will gate return for at the first indication of split and a lag in engine spoil up on thrust lever advancement for takeoff. I believe we have a great procedure of holding the brakes until 75% on both engines for takeoff. It is what counteracts this problem. Also looking down the line at weather is important; if it is going to be IMC or contaminated runways I will lower my threshold of what is acceptable for aircraft quirks which sometimes as pilots we feel are normal.

Data retrieved from NASA's ASRS site as of April 2012 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.