But if the aircraft then transited LHR en-route to LAX, does this not imply that a thorough external pre-flight check was not carried out? Surely, both the PF and the ground crew perform a walkround prior to each and every departure?
Obviously I have never flown anything as big as a 744, so perhaps there are hiding places 'out-of-sight' in the gear bay?
Nasty way to go though.
EDITED as I see others were answering the same question I was in the process of posting.