LEM, with all due respect, I beleive anyone in our industry should
never say never. Anything IS possible, highly improbable with odds at millions to one maybe, but never impossible. Priot to Sioux City, most would have viewed total loss of primary and redundant hydraulics "impossible" in the 10, indeed the manuals had no contingency, but that happened. As aviation professionals, we have an absolute obligation as far as safety is concerned, again I mean this respectfully, but we cannot ever become complacent in any aspects of flight operations.
Best regards