Nick, I'm not aware of the full argument, but saying that the third engine is a penalty due to specific fuel consumption seems a little one-sided.
With the third engine you're given the option to run three and have the OEI performance, or run two and lower SFC. I'm not saying three engines is the way to go, just that the argument is a little more complex than what's been presented here.
[ 09 February 2002: Message edited by: heedm ]</p>