737 Force fight monitor and STBY auto operation
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737 Force fight monitor and STBY auto operation
A bit puzzled by automatic operation of 737 NG’s hydraulic standby system.
FCOM says it will be triggered either by loss of HYD A or B and flaps extended and airborne and flight control switches on OR force fight monitor (FFM) trips.
About the first condition, if A or B fails, FFM will trip anyway so standby system will start. So what’s the point in all the other « and » ??
FCOM says it will be triggered either by loss of HYD A or B and flaps extended and airborne and flight control switches on OR force fight monitor (FFM) trips.
About the first condition, if A or B fails, FFM will trip anyway so standby system will start. So what’s the point in all the other « and » ??
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FFM won’t trip with a failure of a single hydraulic system (A or B). It will only trip when it detects opposing pressure between rudder PCUs powered by hydraulic systems A and B.
