Derated Thrust: Method Analysis for Optimizing Turbofan Engine Takeoff Performances (SFC, EGT) Due to Lower Maximum Takeoff Weight (MTOW) Requirement

Abstract

Reduced thrust or derate has been practiced commonly nowadays as a standard procedure of takeoff. Since power is being used at maximum during takeoff phase, the practice has many benefits for the operation of aircraft. Not only it reduced fuel consumption during the takeoff phase, but also reduced engine’s wear and tear that caused by stress and a very high temperature. Exhaust Gas Temperature (EGT) is one of the most important parameters that used to monitor the engine deterioration. There is a definite correlation between reducing takeoff thrust and EGT reduction, where both values are contradicting one another. However, there must be some calculation by the flight crew on how much percentage of derate is eligible prior to takeoff. The goal of this paper is to find the effectiveness of derate to reduce EGT in order to improve performance, prolong engine life and reduce operating costs of the operators.

Performance and Economic Assessment of Mechanically Integrated Parallel Hybrid Aircraft

“…The severity factor was computed for all cases. It varies depending on the engine derate and flight length [32], [33]. As the engine derate is strongly correlated with EGT [32], it was calculated from the average EGT during TO and climb.…”