Talking of United, thanks to nephew Paul Siegmund et al for spotting the following "alarming" piece from the Australian Herald Sun about a 777 diversion in November because of a faulty (as it turned out) engine fire warning.
"As a precaution, the pilot activated the extinction mechanism and the plane was diverted to Gander, Newfoundland, in the early hours of the morning, he added."
Gosh. That's a bit drastic don't you think?
Source: Flight International