The knock on the pitot tube Thales that AF 447 was sporting was that the drains were susceptible to corrosion. Whether or not this came up for the AD I cannot find...
Not only does crystalline ice need to melt to drain, any corrosion on the drain would nucleate new formation of ice crystals...
So gas path, what is the nature of this deposit, 'blockage'?
Last edited by Lyman; 26th July 2012 at 23:00.