Block 3i software provides the F-35 Lightning II with an initial warfighting capability on upgraded computer hardware.
“As of 1 May, the F-35 program has flown more than 100 flight hours with the 3i software, and it has shown approximately twice the level of stability as the previously fielded Block 2B software and three times better stability than the original 3i software,” the JPO stated on May 10.
“Concluding Block 2B and 3i development and testing now allows the F-35 program to focus on completing Block 3F, the full warfighting capability software. The improvements to Block 2B and 3i have been transferred to Block 3F, and all developmental test aircraft and labs have been upgraded to Block 3F. This will allow the entire enterprise to focus our development and testing on the final Block 3F capability, moving us closer to ending the SDD program.”