Originally Posted by
Microwave
Ehh, fuel burn is not 50% higher when the number of engines increases by 50%.
For example, an A330-300 does not burn half the fuel of an A340-300 on the same route and load. Burn is higher, but only incrementally. It's the marginal maintenance costs that effectively increase with the number of engines.
Microwave is correct. MD11 "only" burnt about 15% more fuel than the 777 despite having 3 engines. The engines themselves were smaller, unlike the 777 engines (which are the largest civil aviation jet engines in the world, especially the GE90 series)
The 777 does not just gain from having one less engine. It also has a more efficient wing etc.
AMR was NEVER happy with the MD-11. In fact, they "bashed" MD-11 pretty hard when they got their first batch of airplanes as they did not meet range and load targets. McDonnell Douglas eventually did offer fixes that allowed the MD-11 to meet range/load targets
However, many enthusiasts (and a couple of TV documentaries) believe that AMR's criticisms of the MD-11 led to SQ cancelling their order and the eventual demise of the production of that aircraft.