ATR72 Flight Crew reports rejecting a takeoff at 100 knots due to engine torque exceeding the planned limit of 90%.
Synopsis
ATR72 Flight Crew reports rejecting a takeoff at 100 knots due to engine torque exceeding the planned limit of 90%.
Narrative
Aborted high speed for torque exceeding the limitation; as per AOM Volume 1; on the #1 engine. Braking input was normal. Expected torque value (and also high end limiting torque value for a normal takeoff on our chart) was 90%. I noted the torque value increasing through 94.5 when I called the abort at approaching 100 knots. Maintenance was notified and when they met the aircraft they told us that this was 'within their limitations' and they indicated no problem with the aircraft. They gave us every indication that this aircraft was going to return to service. We later spoke with Maintenance Control via phone and they had ground run the aircraft and found a 96% torque on the the run for takeoff. I am reporting this event because we had a high speed abort for an engine limitation problem and then maintenance checked it good because they have different numbers. Knowing the safety data on high speed aborts; I feel it behooves the company to review the limitations for both maintenance and line pilots so we can do something to avoid scaring the passengers and causing any more statistics to this 'high speed abort' grouping.
Second reporter narrative
The expected torque value and limiting value for takeoff was 90%. The captain noted the torque value increasing through 94.5 and then called the abort approaching 100 knots (prior to V1). Standard aborted takeoff procedures were followed. Maintenance was notified. When they met the aircraft maintenance indicated that this was 'within their limitations' and they indicated no problem with the aircraft. Maintenance noted that the engine parameters during ground run ups after the event showed a torque of 96 percent in the takeoff power setting and that these were with in their limitations. While 96 percent is within limits of the engines max power; this lies out side of normal takeoff limits. The mechanic in Dallas indicated that there is a discrepancy between their manuals and the pilots and that this was a known issue. The manual differences need to be fixed.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.