Originally Posted by
Stoic
In an ETOPS aircraft, would it not be more sensible to have completely separate temperature monitoring systems for each fuel tank/engine system (disregarding the centre tank)?
Or indeed any large aircraft. If there are big lumps of frozen fuel in your tanks, having four engines wouldn't be much consolation. It is surprising that there appears to be a single point of failure which could cause the loss of an aircraft. If the temperature probe fails completely, I imagine it would trigger an EICAS message, but what if it gives an erroneous but reasonable indication? If you are flying a long sector in unusually low OATs and you don't get a FUEL TEMP LO message, would you descend as a precaution?
OTOH, if the fuel freezes, surely the filters clog, you then get an EICAS message or two and then it's not such a surprise when the engines stop working properly.