Barit1,
It has new pylons has it was not possible to modify the old due to structure. There was some structure strengthening in the crown area above the troop and rudder/fin.
Correct on the climb performance being the primary component of fuel savings with improved fuels specifics being a minority share. The wing loading was notably light compared to the B747 and it was always thrust limited in cruise. Now it can cruise easily in the mid-upper thirties and F410-430 at the end of cruise. A plane that could struggle to fly ETAR to the East Coast with a load now does it easily and can do Incirlik to Dover with that load.
Interesting Vmcg story. L-M discovered that it could not have the same Vmcg at the higher thrust rating, so they proposed assymetry protection with cost and delays; a 5% reduction on 1 & 4 which could have met the performance and Vmcg numbers or a sympathetic reduction when the opposing engine lost a certain N1 reading. I think they went with the last answer as the AF generals were opposed to not getting the contract thrust even if it did provide the performance in the contract. Interesting times.
Last edited by galaxy flyer; 24th May 2017 at 15:41.