The work split between the two companies gave GE responsibility for the high-pressure compressor (HPC), the combustor, and the high-pressure turbine (HPT); Snecma was responsible for the fan, the low-pressure compressor (LPC), and the low-pressure turbine (LPT). Snecma was also responsible for the initial airframe integration engineering, mostly involving the nacelle design, and was initially responsible for the gearbox, but shifted that work to GE when it became apparent that it would be more efficient for GE to assemble that component along with their other parts.