Follow up Question from the 737NG FCOM...
"System A Hydraulic Leak
If a leak develops in the engine–driven pump or its related lines, a standpipe in the
reservoir prevents a total system fluid loss. With fluid level at the top of the
standpipe, the reservoir quantity displayed indicates approximately 20% full.
System A hydraulic pressure is maintained by the electric motor–driven pump.
If a leak develops in the electric motor–driven pump or its related lines, or
components common to both the engine and electric motor–driven pumps, the
quantity in the reservoir steadily decreases to zero and all system pressure is lost."
Okay.... so I don't get how if there is a "Standpipe" in the Hyd A System, how can the hydraulic quantity ever get to 0 percent in the case of a leak in the Elec Hyd Motor or its related lines?
In other words, due to the Standpipe, if there is a leak in the Engine Driven Hyd Pump, you'll still have 20 percent hyd fluid left.
But if the leak is with the Elec Hyd Pump, you'll lose all your Hyd A fluid in spite of having the Standpipe?
Me confused!
Other Question regarding Hyd Sys B:
"System B Hydraulic Leak
If a leak develops in either pump, line or component of system B, the quantity
decreases until it indicates approximately zero and system B pressure is lost."
Ummm, so Hyd B Reservoir also has a Standpipe, but if you get a Hyd B leak the hyd quantity will eventually indicate 0.
Again, how can this be given the existence of the Standpipe?