The Bunker Group
The GAO is recommending that the F135 engine upgrade should be separated from the JSF to better gauge the cost. The other issue in addition to the ECU is the thermal management system. These two systems need to be accessed together to make sure block 4 requirements are fully addressed. As for future needs, AETP, although more risky, might still be needed as new tech always seems to need more power and this means even better thermal management. Also, AETP range improvement (30%) is very enticing.
Congress should mandate the F-35 fighter engine upgrade become its own major program, a new GAO report states, to increase transparency.