Originally Posted by jonny dangerous
Okay, rephrased.
I've had more time to think about my scenario. To follow the question, I submit my thoughts as I see it, and with no FOM directly in front of me, I trust I will be corrected as warranted.
I'm flying along, burning fuel from the center tank. No engine feeding is thus taking place from the left or right main fuel tank(s).
I notice the fuel quantity dropping in the right main tank.Subsequent comparison shows CTR tank quantity to be dropping at the same rate as the fuel flows (2) combined from each engine.
Do I end up at the "Engine" Fuel Leak checklist. And then shutdown the right engine? Is that what I do? Or have I incorrectly interpreted the checklist? Do any other NG operators have an Fuel "Tank" Leak checklist or equivalent in your FOM's?
Would I be prudent to assume the following: Since I am not feeding from the wing tanks, yet the fuel quantity is dropping abnormally fast in ONE of those tanks, could I assume that the engine has nothing to do with the leak, and therefore I will not shut it down right away?
Might I diagnose the scenario and decide to actually cross feed the other engine from that dropping tank. Would I want to burn as much fuel as I could from it, while the fuel is still onboard (and not scattered through the atmosphere)?
Gee, that seems prudent - There's no reason to think shutting one down will be of any benefit, is there? The leak is clearly NOT associated with an engine.
What about an imbalance of one wing tank full and the other empty in an emergency situation (after I have hastened the reduction in fuel quantity in one side)? Can I expect aileron trim (manual flight) to help me maintain straight flight, even if it means higher speeds required?
Yes, aileron trim (and maybe a bit of induced rudder trim too) should work, and I doubt you'll need more than normal cruise speed. But after the leaky tank is drained and you switch back to the opposite side, you'll be heading toward a balanced condition again.
Is there any reason to believe you won't have sufficient aileron available in an emergency unbalanced approach condition? I'm not 737 rated, so you'll have to tell me. Boeing certainly has the data.
One concern I might have is the FW CG condition from a full center tank.