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Actually 2 engine aircraft are probably more reliable for over seas flying then a 747. Which is prolly why the 767 is the number one choice for airlines when flying over seas.
Also I once heard a pliot say that yes a 747 has more engines but that also mean that theres more of a chance that you might incure more problems. Example "more money more problems. More engines possiblity of having more problems.
[/ QUOTE ] I don't buy this logic. I see it as more of a mathematically study...
Factor 1: Assuming independent failures, the probability that 4 of 4 engines would fail would be P to the 4th power (where P is the probability of one engine failing). The probability that 2 of 2 engines would fail is P squared. Assume (only hypothetical) that P=1/1000. Then, the proabably of a 4-engine jet losing all of its engines is 1 in one-trillion. The probability of a 2-engine jet losing all of its engines is 1 in one-million (much more likely).
Factor 2: Many engine failures are not independent. (bad fuel, idiot mechanic who systematically does wrong thing, explosion which takes out another engine, etc).
Factor 3: Engines can be hazardous to flight, even if you have spares. They can explode and catch fire. The more engines you have, the more potential there is for such hazards. The probability that one of the engines may create a hazard is proportional to the number of engines. P*N, where N is the number of engines. Assume engine hazards occur at a rate of 1/1000 (again, totally made up number for purposes of this example). Then a 4 engine plane will have a hazard rate of 1/250, whereas a 2 engine plane will have a hazard rate of only 1/500 (better).
Now that I've bored everybody with the numbers, I'll tell you that I don't really care if I'm on a 2 or 4 engine plane. They're both safe. I'd prefer the 747 because it's big, and looks really cool.