www,you are completely wrong if you think a 4 engine aircraft on 2 is similar to a 2 engine aircraft on 1. A 4 engine jet has most of the performance prescribed for the loss of 1 engine.There is a certain level of flexibility after that which considers the loss of a further engine case,terrain clearance on 2 etc.However to say that the loss of 2 engines is comparable to a twin on one is complete baloney.2 engines out on an A340 or B747 will take you very smartly downhill and dependent on the weight/atmospheric conditions all the way down.Not the case of a twin on 1,I think you would agree.
No way would I get into making commentary on the crew who made their decision in the light of the conditions on the day(night) and they have my respect for that.As I recall the actions they took were not technically wrong,but obviously went a bit pear shaped towards the end.It really boils down to risk management;to continue on 3 is fine(and allowed) but if another engine fails you are in deep doodoo.similarly there would be a performance calculation to make based on 3 engines -all of which they made.
www,I believe you work for a 737 loco with orange colours (same as me,actually) and I know you are an enthusiastic contributor to pprune and there is nothing wrong in that.My take is that you are unlikely to have an encyclopeadic appreciation of either long haul ops or 4 engine performance.I have 16 years worth of jet lag in my log book which does not make me the definitive expert either but I have flown those types and routes and understand the pressures/difficulties that may occur.In summary,authorative statements made on pprune which are downright wrong help noone's case.it is hypocritical to damn journalists for their technical innaccuracies then go ahead and demonstrate the same.
with b/rgds