View Full Version : Thrust Rating
mfclearner
9th Apr 2011, 01:54
I am not really sure about what is meant by engine thrust rating. In terms of B737 CFM567 Engine it is said to be 10 minutes of thrust rating. Now what does this 10 minutes signify? Any pointers are highly appreciated.
NZScion
9th Apr 2011, 05:07
Should this maybe be in SLF? Not unless it is a question best answered by passengers.
Anyway, some engines are only 'rated' to provide a certain amount of thrust/power for a certain amount of time. This is to protect the engine from unnecessary wear and tear.
Some engines may be able to produce more thrust than the maximum rating, and some engines may have a certain thrust setting which can only be exceeded for a limited amount of time before the pilots must reduce to a lower setting.
Whilst I'm not familiar with the CFM56, I would assume your example means a limit of 10 minutes of take-off thrust is available to be used. This means the pilots can set Take-Off Thrust for a maximum of 10 minutes, before they must reduce power to a lower Maximum Continuous Thrust (MCT) setting.
A 10 (or cheaper to buy 5) minute limit applies to take off thrust. User selectable thrust settings are something different but still the norm on the 737 which after all only uses different versions of the CFM56. Those are used for take off only, but do not have a time limit in itself apart from the general take off thrust time limit.