The Defense Department and Government Accountability Office don't fully agree on how to manage and report on F-35 Joint Strike Fighter engine and thermal management modernization efforts, according to a report released Tuesday . GAO’s study into the program and its Block 4 modernization effort found that F-35 procurement costs have increased by $13.4 billion since the last cost estimate in 2019 with Block 4 costs ballooning to $16.5 billion -- more than a $1 billion increase since the last...
