twin engine ETOPS vs four engines
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twin engine ETOPS vs four engines
For ETOPs flights does the overall cost still come in lower than using a four engine jet on the same route.
For instance would it be cheaper to use a 777 on a route that was previously served by one 747 once the costs of ETOPS checks, routing, Oil Consumption limits etc. are factored in.
For instance would it be cheaper to use a 777 on a route that was previously served by one 747 once the costs of ETOPS checks, routing, Oil Consumption limits etc. are factored in.
Last edited by shon7; 26th Feb 2007 at 19:17.
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For instance would it be cheaper to use a 777 on a route that was previously served by one 747 once the costs of ETOPS checks, routing, Oil Consumption limits etc. are factored in.
For ETOPs flights using twin engine jets
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Yes I have to agree with barit1. However, I heard - some time ago - of moves to reintroduce EROPS, which applies to... well, it doesn't matter how many or how few engines. The cynic in me thinks this might have been Boeing being bloody-minded about the A380 but that's probably not right... 
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Etops -->erops
Quote:
I heard - some time ago - of moves to reintroduce EROPS, which applies to... well, it doesn't matter how many or how few engines.
Where did you get it?
I heard - some time ago - of moves to reintroduce EROPS, which applies to... well, it doesn't matter how many or how few engines.
Where did you get it?
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Read on a magazine (do not remember which one) that ETOPS systems concept and maintenance standardization could save $$$ in a company with different acft fleet on service.
Personally unable to demonstrate if right or wrong.
Personally unable to demonstrate if right or wrong.
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I don’t think there is a simple answer to your question, but I strongly suspect that factors other than ETOPS will drive the economics of the aircraft. Economics will be influenced by existing fleets, route structure, traffic densities, number of aircraft needed per day to meet the demand at a reasonable load factor, range requirements (and, yes, the need for ETOPS capability).
I know that Direct Operating Costs are important (they include fuel, maintenance [line, airframe, engine overhaul reserves, components and LRU inventory charges], total crew and attendant employment costs, navigation and landing fees, passenger catering and aircraft lease charges). But the total annual costs of operation, and consequently trip costs, are also influenced by aircraft utilisation and number of available seat-miles (ASMs) generated.
In simple economic terms, the two-engined aircraft is often preferred to the four engined aircraft where ETOPS allows. But then the real world can intervene on a particular route - one of the medium range analyses I have shows that the 777-300 and A340-600 have virtually equal trip costs on the route, but the 777-300 has a 32-seat higher standard seat capacity. The 777-300 was therefore able to operate at one [daily] frequency lower than the A340-600 while traffic grew, and so generated a total higher margin.
777 vs a 747? I reckon the 777 wins often, until the route gets busy and you need two 777s to compete with the 747. The costs of ETOPS checks don’t really feature in the sums.
I know that Direct Operating Costs are important (they include fuel, maintenance [line, airframe, engine overhaul reserves, components and LRU inventory charges], total crew and attendant employment costs, navigation and landing fees, passenger catering and aircraft lease charges). But the total annual costs of operation, and consequently trip costs, are also influenced by aircraft utilisation and number of available seat-miles (ASMs) generated.
In simple economic terms, the two-engined aircraft is often preferred to the four engined aircraft where ETOPS allows. But then the real world can intervene on a particular route - one of the medium range analyses I have shows that the 777-300 and A340-600 have virtually equal trip costs on the route, but the 777-300 has a 32-seat higher standard seat capacity. The 777-300 was therefore able to operate at one [daily] frequency lower than the A340-600 while traffic grew, and so generated a total higher margin.
777 vs a 747? I reckon the 777 wins often, until the route gets busy and you need two 777s to compete with the 747. The costs of ETOPS checks don’t really feature in the sums.
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Comparing apples and oranges. . .?
Yes, it's cheaper to operate the 773 than the 744, . . . if you were to tighten the seat pitch and pack 406 pax into the 773. . . . But then again, you could tighten the seat pitch in the 744 and stuff 550 pax into it. Impractical comparison.
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Not impractical if you're in the business of making money from the route, and a commonly made comparison. The question is better phrased in terms of what pax loading you've got and what size aircraft fits. A strong driver for the growth of the 777 (and the other twins) has been precisely because they are that little bit smaller than the 747 and can service a wider range of city-pairs at a decent frequency and good load factor. On the [few] very busy trunk routes of the world, the 747 wins hands down over the 777. Until the A380 comes along, and then the analysis of capacity vs number of aircraft needed will dictate the relative economics of the 747 and the A380. Back to the original question - the cost of ETOPS isn't a strong driver [apart from exceptional circumstances on a couple of routes].
Weight for weight, a 777-200 is more economic to run than a 747-400. However, capacity is reduced slightly in the 777-200. BA has found this out and the 772 has taken some 744 routes to save money. A more modern engine on the 744 would, no doubt, reduce the 772's advantage.
The slight reduction in capacity of the 772 is then more than made up for by using the 744 on routes with high premium-seat demand.
The slight reduction in capacity of the 772 is then more than made up for by using the 744 on routes with high premium-seat demand.
