Pinkman
As I see it, the extension of the tubes past the Face into a 100% Fuel (cold) environment allowed Ice to accumulate and prevented it from reaching the hotter portions of the HE, the Face. As Sooty says, the goal seems to be to expedite the Ice's migration directly to the Face itself. The schematic I have seems to show the From Engine Oil entering the FOHE at the Fuel exit. The FOHE Away Oil (cooled) seems to be exiting at the Face FOHE. I'd like to be wrong, since I think the Hottest Oil should be at the FOHE's Face.
My question is the region between all the tubes can accomodate some volume of Ice, and trap it out of Harm's way (theoretically), unless the slug of Ice is too large for this and then plugs the 1080 openings. In any case, though helpful, I don't think the foreshortening of the tubes to the Face accomplishes enough to solve the problem.
BA038 Rolled Back after an increase in Fuel was commanded, and the Thrust increased. Did the vibration of added thrust shake loose a quantity of Ice that then occluded the FOHE's? If so, what purpose does the AD's call for occasional max thrust solve? Then return to Idle to melt whatever accumulation has presented? The AD seems insufficient. The GE and Pratt engines, not having had a rollback (seemingly) does not mean they won't or that they haven't and weren't diagnosed properly. The RR fix seems short of the mark. If the AD is used, should it coincide to proximity to an alternate?
AF
Last edited by airfoilmod; 18th March 2009 at 23:01.