I congratulate HM's security for foiling this plot. Given the conditions in Heathrow, I'm amazed those folks can find so much as a pocketknife.
Wasn't there a recent story about Heathrow closing down some 'impromptu' or 'unauthorized' muslim prayer rooms there? I wonder if that is related to this, maybe the perps were goint to 'prep' their stuff in the airport just before boarding....Creepy!!