Narrative:

We were requested to use maximum power for our takeoff from ewr in order to satisfy our company's scheduled checks on engine performance. We made a rolling takeoff with automatic throttles engaged. Following up the throttles we saw engine #2 was 2-3% shy of the desired N1. Manually advancing the #2 throttle to its stop did not increase the N1. By this time the aircraft had accelerated to a speed (approximately V1) wherein aborting the takeoff would have subjected the passenger to a possible ground evacuate/evacuation and injury and the aircraft to probable damage. Since the aircraft's performance was not noticeably affected and no emergency then existed, the decision was made to continue the takeoff. This was done uneventfully. Rather than continue the flight to its overwater destination with 1 engine unable to develop maximum power, the flight diverted to jfk for corrective maintenance. Landing weight was not exceeded and the entire flight was conducted west/O incident. Callback conversation with reporter revealed the following: the power check on takeoff was not made because this was an overwater flight. Power checks are made on all aircraft periodically to ensure the engines are capable of full power because most takeoffs are made at reduced power and a power limiting anomaly might not be discovered until full power was needed in an emergency situation. Which takeoffs will use full power is determined by the air carrier and indicated on the dispatch release.

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Original NASA ASRS Text

Title: WDB DIVERTED TO ANOTHER ARPT WHEN AN ENGINE PROBLEM WAS DISCOVERED ON TKOF.

Narrative: WE WERE REQUESTED TO USE MAX PWR FOR OUR TKOF FROM EWR IN ORDER TO SATISFY OUR COMPANY'S SCHEDULED CHKS ON ENG PERFORMANCE. WE MADE A ROLLING TKOF WITH AUTO THROTTLES ENGAGED. FOLLOWING UP THE THROTTLES WE SAW ENG #2 WAS 2-3% SHY OF THE DESIRED N1. MANUALLY ADVANCING THE #2 THROTTLE TO ITS STOP DID NOT INCREASE THE N1. BY THIS TIME THE ACFT HAD ACCELERATED TO A SPD (APPROX V1) WHEREIN ABORTING THE TKOF WOULD HAVE SUBJECTED THE PAX TO A POSSIBLE GND EVAC AND INJURY AND THE ACFT TO PROBABLE DAMAGE. SINCE THE ACFT'S PERFORMANCE WAS NOT NOTICEABLY AFFECTED AND NO EMER THEN EXISTED, THE DECISION WAS MADE TO CONTINUE THE TKOF. THIS WAS DONE UNEVENTFULLY. RATHER THAN CONTINUE THE FLT TO ITS OVERWATER DEST WITH 1 ENG UNABLE TO DEVELOP MAX PWR, THE FLT DIVERTED TO JFK FOR CORRECTIVE MAINT. LNDG WT WAS NOT EXCEEDED AND THE ENTIRE FLT WAS CONDUCTED W/O INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: THE PWR CHK ON TKOF WAS NOT MADE BECAUSE THIS WAS AN OVERWATER FLT. PWR CHKS ARE MADE ON ALL ACFT PERIODICALLY TO ENSURE THE ENGS ARE CAPABLE OF FULL PWR BECAUSE MOST TKOFS ARE MADE AT REDUCED PWR AND A PWR LIMITING ANOMALY MIGHT NOT BE DISCOVERED UNTIL FULL PWR WAS NEEDED IN AN EMER SITUATION. WHICH TKOFS WILL USE FULL PWR IS DETERMINED BY THE ACR AND INDICATED ON THE DISPATCH RELEASE.

Data retrieved from NASA's ASRS site as of August 2007 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.