Fuel Imbalance Event
 

I found this incident interesting. I know the effects of an imbalance can vary from aircraft to aircraft with potential serious consequences for some. I was wondering if the procedure followed here was something in the checklist or an outside of the checklist action that may very well have become necessary.

"a CL-600-2D24 (CRJ 900 series) operated by xxx, was operating flight xxx from AAA to BBB. On departure out from AAA, the crew observed a crossflow caution message and a fuel quantity imbalance that could not be controlled. The fuel imbalance was substantial enough that the crew elected to shut down the right engine. The crew requested a clearance to return to AAA where they carried out an uneventful landing. A subsequent inspection by the operator's maintenance revealed a failed cross-flow pump."

I have had demonstrated in a simulator, in both an A320 and a B787, that they fly perfectly well with one wing full and one wing empty. Of course the actual aircraft might be different but both instructors insisted that they would be the same.

This would be expected from FBW aircraft. Probably not hold true for non FBW models. The nonFBW transports I have flown had imbalance limits and the FBW transports did not have limitations.

According to Airbus A320 can be landed with one side full and other empty. But that will only be true in normal law because the computers will hold the lateral position as commanded. But in alternate and direct law that will not be the case. The pilot will have to keep wings level.

My experience is on non FBW Boeing types [737 757 767) Advice sought from Boeing and published in the Company’s Training Guidance is that fuel asymmetry poses no handling problems, even with one wing full and the other empty. The primary purpose of fuel balance limitations on Boeing airplanes is for the structural life of the airframe and landing gear and not for controllability. A reduction in structural life of the airframe or landing gear can be caused by frequently operating with out-of-limit fuel balance conditions. Lateral control is not significantly affected when operating with fuel beyond normal balance limits. The primary purpose for fuel balance alerts is to inform the crew that imbalances beyond the current state may result in increased trim drag and higher fuel consumption.