MCT V TOGA 744F

[FLEX1978 373]

Ok after spending a good few weeks practising abnormals in the MD11 I'm finaly converted to flying this work of art full time :( But hopefully someone can answer something that has bugged me on the 744 all this time. for some reason MCT thrust gives me a higher N1 or EPR then TOGA thrust, obviously this is wrong, can anyone confirm they are also seeing this?CheersRob Prest

[downscc 1,327]

Just guessing here (cause I don't really know either) but MCT=Max Continious Thrust would almost always be higher than normal takeoff thrust (max higher than norm)?

[FLEX1978 373]

Just guessing here (cause I don't really know either) but MCT=Max Continious Thrust would almost always be higher than normal takeoff thrust (max higher than norm)?

Hey Dan, MCT is the max thrust available without restrictions, TOGA is a time limited MAX thrust setting due to eventual damage to the engines. TOGA should always be higher then MCT.CheersRob

[Check_Airman 3]

I presume there's something that the engineers know that I don't because I've observed the same thing in other planes too. TOGA will give 100% and MCT will be 103%. Very strange. I often see it at higher altitudes.

[Airbrakes 0]

The EPR/N1 thrust limit is inhibited by the EEC's for 5 min when a GA is activated/performed. It's also inhibited for a few min during TO.

[Spidierox 4]

I presume there's something that the engineers know that I don't because I've observed the same thing in other planes too. TOGA will give 100% and MCT will be 103%. Very strange. I often see it at higher altitudes.

Rob did explain it right : MCT is really pushing the engines into the red (I do think it is limited however).TO/GA gives the max possible thrust to the red limit...Ok this might be a simple look at things but hopes it makes more sense...So MCT > TO/GA is the way to go....

[Spidierox 4]

Aah just found some numbers ( have the 747 manual always handy):EGT and thrust maximum (time limit / EICAS color / EGT- degr. celsius)Ground start 40 sec / red bar / 870TO/GA 5 min / Red bar / 960MAX CONT None / Amber / 925So when EGT is going over the red for MAX CONT (925) you must select a lower thrust setting.