chrisarrow

There is a fault in the logic of the Fuel Pump behavior in the scenario of Right Hand engine shut down while attempting to re-balance the fuel. Here is the scenario: Right Engine suffers a failure, engine is shutdown in accordance with the checklist. APU is also started in accordance with the checklist. High Fuel Flow from the Left Hand Engine comparative to the zero fuel flow from the now failed right engine leads to a FUEL IMBALANCE scenario with the Left-Hand Tank being of lower quantity. FUEL IMBALANCE checklist is carried out, which involves turning on either CROSSFEED VALVE and turning off the LEFT FWD and AFT Fuel Pumps switches. 30 minutes later, fuel is continuing to drain from the left hand tank at a faster rate.... WHY? If you look at the FUEL SYNOPTIC you will note the Left FWD AC Pump is still running and providing fuel from the LEFT WING TANK to both the LEFT ENGINE and the APU. This is incorrect logic, in this situation you will never be able to balance the tanks, unless you turn off the APU. ONLY on the ground will the LEFT FWD AC Pump operate in this situation. In flight the correct action of turning the LEFT FWD AC Pump switch OFF should be that the pump stops operating. APU fuel will be provided from the RIGHT MAIN AC Pumps via the cross-feed valves and the left fuel manifold. Source: Real Life 777 Pilot, and Boeing 777 FCOM 1 Systems

Hi Richard, Here is what we use in my airline on the 777: Configuration is done on distance to threshold, and assumes a normal ILS glideslope angle. Provided the FMC is programmed for the approach, use the PROGRESS page to see the distance to go. 14-18 NM: Flap 1 By 10 NM: Flap 5 By 8 NM: Gear Down, Flap 20 By 6 NM: Flap 30 Aim to be back at the Flap Up manoeuvre speed (~230 Knots) by the time you want to start configuring. Normally you will have Flap 1 or 5 out by the time you are on an intercept heading to the localiser, this helps managing the momentum to prevent and overshoot of the localiser. By 1,500 FT AGL you want to be stabilised at VREF + 5, and fully configured for landing. The advantage of configuring on distance rather than on altitude off the altimeter is that it simplifies the process without having to worry about aerodrome elevation.