Max Continous Vs Max cruise thrust for Beechjet 400
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Max Continous Vs Max cruise thrust for Beechjet 400
MCT vs Max Cruise Thrust
Hi , just wondering if anyone can enlighten me on the following point , taking into consideration I fly a Beechjet ......or if the below holds good for all jet aircraft ?
BELOW STATEMENT TO BE CONSIDERED AT FL410 :
1.Why is it that the Max continous thrust ( 103.2% n1 ) as per the MCT chart is less than the Max Cruise Thrust permitted ( 104.0% n1) ??
The above is causing me confusion , as Max continuos in my mind means THE MAXIMUM CONTINOUS THRUST that can be produced by the engine ..... therefore it should be higher than the Max Cruise thrust !!!!
Thanks in advace , all relevant replies welcomed.
SK
Hi , just wondering if anyone can enlighten me on the following point , taking into consideration I fly a Beechjet ......or if the below holds good for all jet aircraft ?
BELOW STATEMENT TO BE CONSIDERED AT FL410 :
1.Why is it that the Max continous thrust ( 103.2% n1 ) as per the MCT chart is less than the Max Cruise Thrust permitted ( 104.0% n1) ??
The above is causing me confusion , as Max continuos in my mind means THE MAXIMUM CONTINOUS THRUST that can be produced by the engine ..... therefore it should be higher than the Max Cruise thrust !!!!
Thanks in advace , all relevant replies welcomed.
SK
Hello Skyking!
I would like to answer you exactly, but I'm not quite sure about this one.
My humble suggestion is that :
Max Cruise is higher because the Aircraft is straight and level, which is the best attitude for engine operation.
Max Continuous is less because high angle of attack are considered, that's why there is a margin.
Engine operation at high AOA is less efficient (air intake).
That is my theory, Skyking, but as you, I would be pleased to hear from a specialist!
FLEXJET
I would like to answer you exactly, but I'm not quite sure about this one.
My humble suggestion is that :
Max Cruise is higher because the Aircraft is straight and level, which is the best attitude for engine operation.
Max Continuous is less because high angle of attack are considered, that's why there is a margin.
Engine operation at high AOA is less efficient (air intake).
That is my theory, Skyking, but as you, I would be pleased to hear from a specialist!
FLEXJET
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Thanks
Hey Flex jet , thanks a bunch , thats what I figured too , asked my captain about the same , he said I was close to the answer but not yet pinned down on it , so am still looking for the clearer picture. The Ram effect of air on the intake must be the cause , because of compression of air , increase in density , therefore greater mass airflow. I also wonder if this holds true for all jet engines aircrafct our to certain aircraft only.
cheers and thanks once again
SK
cheers and thanks once again
SK
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SK,
After a brief group huddle here the answer we came up with is:
MCT - The max recommended thrust to be applied to the remaining engine in a single engine configuration. i.e. You lost one and need to set a thrust on the good one that you can sit at all day and not cause any detrimental effects. Climb power is OK but is part of a separate set of calculations when determining engine life. Time spent at climb power is a forecast percentage of power usage and can have an effect when exceeded.
Max Cruise - A manufacturer recommended cruise setting for optimal cruise performance without requiring reference to AFM cruise charts. Not a limitation but a recommendation.
These definitions are relative to G.E but should be generally applied throughout the industry.
After a brief group huddle here the answer we came up with is:
MCT - The max recommended thrust to be applied to the remaining engine in a single engine configuration. i.e. You lost one and need to set a thrust on the good one that you can sit at all day and not cause any detrimental effects. Climb power is OK but is part of a separate set of calculations when determining engine life. Time spent at climb power is a forecast percentage of power usage and can have an effect when exceeded.
Max Cruise - A manufacturer recommended cruise setting for optimal cruise performance without requiring reference to AFM cruise charts. Not a limitation but a recommendation.
These definitions are relative to G.E but should be generally applied throughout the industry.
