In the comments section of The Register May 13, a Heathrow mechanic for 777s said large transports landing from long flights at altitude in cold conditions were showing up with booster pumps with frozen intakes and that check valves held open with solid ice were also seen. He states he personally changed some of these pumps. I took booster pump to mean the LP pumps in the wing tanks. This may be a reliable report, because it seemed to fit with the physical test program AAIB stated in their May 12 supplemental report (3 pages). Here is the link:
From The Register, London, publ 5-13-2008, URL =
Heathrow 777 crash: Siberian cold to blame? | The Register
His comments are easy to find among the few on the website, at the AAIB story.
My own thoughts are that something like closing the throttles to flight idle at some reasonably high altitude in the landing regime would increase the LP pump discharge pressure. In turn, this would decrease pressure at the impeller area of a centrifugal pump, as this pump is. I know this is very counter-intuitive (so pump engineers tend to be specialists). Under the right adverse conditions, a decrease in pressure within the fluid fuel column could cause ice crystals to precipitate out of solution or entrainment, where before the water content may have been causing no problem.
OE