I don't know what sort of aeroplane BA/BY has been flying but I simply cannot go along with his statement that "the wing, stab and fin are completely clear of contamination. Each time, every time without exception". Is he really telling me that every time I taxied my DC-10 through the de-icing rig at CDG I did this? Not once on a BAe146 did I ever get out, mount a 30 foot cherry-picker and check the upper surface of the stabiliser. There are times in aviation that you have to rely on others to have done their job.