How is crossing the Atlantic with three engines (a 747 with one out) any less safe than crossing the Atlantic with two engines (on a two-engine A310 or 777)?
Didn't the FAA give Boeing a hard time over the two engine 777, extra rigorious testing etc? I recall reading something along those lines.
What would be the range of the aircraft if it lost another engine on the same side? Three-engine aircraft can operate on any two, but I would expect a 4-engine aircraft to be problematic at best with two same-side engines; even the case of flying with near-left and far-right or vice versa would seem difficult (there's not a whole lot of extra thrust, and some would have to be wasted to keep things balanced).
You are much less safe flying over blue water with only three engines, because you can't climb to proper cruising altitude and so burn more fuel. Which is exactly what happened - the plane barely made it to Manchester.
Another aspect of the story that seems left out is that the decision to fly on saved British Airways over $200k in compensation they would have been required to pay. What a coincidence - the compensation regs come into force on 1 March and suddenly BA allows its planes to fly minus one engine.
Fly Boeing. But don't fly BA.
Presumably the twin engine planes are designed to fly on one engine. And presummably the four engine planes are design to fly on two engines. Three out of four would seem better than one out of two. But this is not the point. Flying on three engines is less safe than flying on four. When you have the whole length of the United States to land for repairs but don't, one has to conclude British Air will take unnecessary risks with passenger's lives. I can easily imagine unfavorable prevailing winds and being forced to fly less efficiently at lower altitudes could have caused this flight more trouble than it did.
Without having a mechanic out on the wing to figure out what the failure is, it's a helluva lot less safe than a fully operational 777.
Unexpectedly losing an engine from an unknown failure which may be ticking seconds to a further systemic collapse is not the same as simply starting off the day without starting an engine.
You seem smart enough to know this...why make such a silly point?