Re: iced up AF447 pitot tubes
"In the case of AF447 it was also related to the _type_ of pitot used"
"why you'd want them all from the same maker I'm not quite sure"
That's not permissible, exactly because "it means they may all fail the same way"
"Nonetheless, that's what airlines insist on"
If they do, it'll be news to a lot of people. Three pitot tubes of two dissimilar designs is the usual requirement. There's a reasonable description in the AF447 wikipedia article. Three sensors, two designs, so as to reduce the risk of two plausible but identically wrong signals outvoting a correct but implausible signal. Reducing the risk doesn't necessarily eliminate the risk. In recent years mergers and acquisitions among suppliers may have introduced hidden risks - different model numbers, shared design features.
'Dissimilar redundancy' needs to be properly enforced by people with a clue, people who understand the 'bigger picture', typically not people with MBAs and years of headcount reduction and introduction of inappropriate 'cost reduction' programs. MBAs etc tend to understand the wrong kinds of redundancy :(
ps re Lucas
Who do you think has been designing, making, and supporting the fuel systems, FADECs, etc, for the engines on a large proportion of Airbus and Boeing's widebody jets, amongst others?
Does the name Trent ring any bells?