I agree its a real pity the RR Trent isn't an option on the 777-300 or LR but even if it was AF wouldn't buy them with RR!
Lets nor forget the BA ac that crashed at LHR was RR powered, whilst no fault has, as yet, been found to lie with the engines!
. I believe BA ordered RR on it's later 777s due to problems with the GE engines on it's early build 777s. it's unusual to say the least to go mixed fleet when you dont have to, so there must have been some issues. I know there have been quite a few GE/777 incidents but that may just be because they are more numerous due to their exclusivity on the -300 in particular.
Lets just wait and see what the outcome of this and the BA crash is before we lambast a particular engine, remember these modern large fan engines are far more reliable than anything was even 10 years ago.
