Engine and airframe manufacturers for decades have cited the direct relationship between engine wear and high exhaust gas temperature (EGT) in recommending that operators use less than maximum takeoff thrust whenever possible. While the cost benefits of reduced-thrust takeoffs are thoroughly documented, the safety benefits are not as well understood.
Thus, there is a common perception that using reduced thrust is less safe than taking off with full-rated power. Undoubtedly, maximum thrust will provide maximum takeoff performance. However, using reduced thrust does not mean that safety margins are reduced. There actually is a significant safety benefit: By increasing engine life, reduced-thrust takeoffs reduce the chances of engine failure.
A key factor in this concept is that turbine engines are guaranteed to provide maximum thrust at and below a specific ambient temperature — 30 degrees C for the CFM International CFM56-7B series, for example. At higher temperatures, maximum avail…
