SeenItAll
Thank you for that link. I was right in my guess that 330 minutes means nigh on everywhere (other than Antarctica) is included.
On a previous thread (yes that one about the BA 744) some posters made comments that just because it something is possible and within SOPs etc. should it be allowed. I can see both sides of the argument - but (my background is in mathematics/computing) statistically the risk of the second engine failing will increase the longer an aircraft has to fly. The decision the FAA is making is that risk is small enough to take the chance - but the risk will have got bigger.
While most passengers will not care and are driven by cheaper fares, I will continue to pay extra to fly my family and I on airlines that use 747's or 340's. The risk of losing 3 engines in 5 hours is much smaller - and when it comes to my family - then that is worth any extra.