I was over Canada at the time of this incident and heard most of it unfolding over the radio:
From what I could hear, there had been electrical smoke in the flight deck. The pilots had donned their oxygen masks but still managed to communicate quite well with ATC.
Quite a nasty incident when you're over a remote area of Canada (250Nm North of Montreal) and it's dark. By the time they made the decision to divert to CYUL it sounded like the smoke was dissipating and things were getting better. ATC were trying their best to be helpful and suggest suitable diversions. That said, declaring a PAN didn't have much effect so MAYDAY did the trick.
The crew seemed to be on top of things but I was slightly surprised by how long it took them to actually declare an emergency. It often seems that pilots don't like to say those magic words, "Declaring an Emergency" or Mayday. I wonder why? Is it because we secretly feel like it was our fault, maybe we could have done something to avoid it?
Food for thought but well done to the crew of BA288 who got their big white bird down safely.
LFW