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ETOPS (Modern engines now are so dependable that I think the longest certification available now is up to 360 minutes on a single engine, though I'm not sure how the asymmetrical thrust would actually play out. Perhaps someone educated in this subject can enlighten me.)
Economics. Why pay for the added cost, wear+tear, and weight penalty for four engines when two will go just as far in the same amount of time.
The 777 was really the beginning of the end for the 747. The latter was a a victim of the formers success.
Our group took a 777 NY to China non stop. To our dismay only 2 engines and all previous trips to Asia had 4 engines.
Departed 3:30 pm EST = nice. Lots of daylight and the sun should still be out as we leave the west coast. Wrong!
The route went north thru Vermont, Montreal and the thru Husdon Bay and even further north. Altitude was max. at 29,000 feet so we thought maybe that is why only 2 engines. 7200 miles and 14.25 hours non stop on 2 engines. Crash up near the North Pole and we'd never been found. 14+ hours is a long haul. We maybe had 30 minutes extra fuel.
Around half way we went up to about 35,000 feet and maintaind that for the duration.
Is this the airline cutting corners and going with 2 engines? They do have many planes with 4 engines and surely 14+ hours is one of the longest flights there are.
Four engine airliners are a dying breed. You can rest assured that all your perceived safety issues concerning twin engine jets on long haul routes, were addressed when these airplanes first went into service.
Our group took a 777 NY to China non stop. To our dismay only 2 engines and all previous trips to Asia had 4 engines.
Departed 3:30 pm EST = nice. Lots of daylight and the sun should still be out as we leave the west coast. Wrong!
The route went north thru Vermont, Montreal and the thru Husdon Bay and even further north. Altitude was max. at 29,000 feet so we thought maybe that is why only 2 engines. 7200 miles and 14.25 hours non stop on 2 engines. Crash up near the North Pole and we'd never been found. 14+ hours is a long haul. We maybe had 30 minutes extra fuel.
Around half way we went up to about 35,000 feet and maintaind that for the duration.
Is this the airline cutting corners and going with 2 engines? They do have many planes with 4 engines and surely 14+ hours is one of the longest flights there are.
I say this with all due respect: You don't have any idea how much extra fuel the aircraft had upon arrival. I'd bet my house that you had adequate reserve upon landing.
As far as your initial level-off at 29,000 feet, that is normal on a long-haul flight regardless of how many engines are turning. In fact, the 2-engined aircraft usually has more "extra thrust" available than a 4-engined aircraft, due to design for engine-out requirements during takeoff: The twin-jet must be designed to suffer a loss of 50% thrust (loss of one engine out of two), as compared to a loss of only 25% for the 4-engined aircraft (loss of one engine out of four).
I've seen studies done about 4 vs. 3 vs. 2 engines required to cross the ocean. Surprisingly, having 4 engines does not necessarily mean a safer faster flight to your destination.
Lets say Aircraft A has 4 engines. For arguments sake, assume the engines have half the mean time between failure as the newer generation.
Aircraft B has 2 engines that have roughly twice the mean time between failure.
Using very generalized assumptions for statistics, we can say that Aircraft A has roughly 4 times the probability of Aircraft B having an Engine Failure.
Finally there is always the possibility on both Aircraft that if a catastrophic engine failure occurs, There is a probability that a thrown blade or screw will impact other systems or another engine. Aircraft A with 2 engines on each wing (4 total) has a much larger probability of one engine failure affecting another engine due to their close proximity. So Suddenly a four engine plane is down to two engines in close proximity. Because Aircraft A has older engines which are in close proximity, it still has a much higher chance of engine failure and possible aircraft loss.
With modern engines, all of these probabilities are extremely low. Most engine failures because of external factors such as multiple bird strikes, Ingestion of FOD while taxiing out, etc. Bottom line you should feel equally safe on both. I just wanted to demonstrate that it in certain circumstances, it is possible for 2 engines to be better than 4.
Our group took a 777 NY to China non stop. To our dismay only 2 engines and all previous trips to Asia had 4 engines.
Departed 3:30 pm EST = nice. Lots of daylight and the sun should still be out as we leave the west coast. Wrong!
The route went north thru Vermont, Montreal and the thru Husdon Bay and even further north. Altitude was max. at 29,000 feet so we thought maybe that is why only 2 engines. 7200 miles and 14.25 hours non stop on 2 engines. Crash up near the North Pole and we'd never been found. 14+ hours is a long haul. We maybe had 30 minutes extra fuel.
Around half way we went up to about 35,000 feet and maintaind that for the duration.
Is this the airline cutting corners and going with 2 engines? They do have many planes with 4 engines and surely 14+ hours is one of the longest flights there are.
And you know you had 30 minutes how? Per FAA and international fuel reserve requirements you would have been deep into a min fuel or emergency situation.
I like 4-engines because usuall the flight is less noisy, engines are not that strong compared to the big twin engine planes and thererfore a bit more quiet. Had that experience on A340 and IL96 at least. However for economical reasons the twin engine plane is always better- less weight, less fuel burn, less maintenance. The longest flight I have ever taken was SIN-EWR on an Airbus A340-500, something like 18 hours and something like 200 tons of fuel. However the airplane with a similar range is a Boeing 777-200LR twin engine airplane. You really can not say that 4 engine is giving a longer range. Basically the only airplane really requiring 4 engines is an A380 due to its enormous weight.
Everyone knows 6 engines are far more safe than 4.
I am still waiting to fly on the Antonov AN-225 for that reason, but so far they didn't want to take me on this plane.
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