Originally Posted by
Noknoipobin
From FCOM
The thrust management function operates the autothrottle in response to flight crew mode control panel inputs or to FMC commands.
-calculates reference thrust limits and thrust settings, or follows FMC thrust settings
-commands thrust levers
then EEC controls engines to achieve THR
EEC doesn’t compute N1, just controlling or scheduling N1 as above mentioned.
TMS/FMC “ I need 95%”
ECC. “. Yes sir “
My question might sound stupid…but you wrote
-If the thrust lever is here , the required N1 should be this value.
If TMS/FMC are already doing the maths for the target N1 to be achieved, why is EEC trying to figure out what is the N1 value ? Why can’t TMS/FMC just send the target directly to the EEC?
From what I understand, TMS/FMC are doing the maths to figure out what’s the target N1. Behind they position the thrust levers. Given their position, EEC also does the maths using different parameters + TLA to figure out the required N1…sounds a bit redundant. Also implies that TMS/FMC know the EEC parameters (Mach, pressure etc) as well to position the thrust levers correctly.