A Pratt & Whitney F135 engine undergoes ground testing at Arnold Air Force Base in Tennessee. (Rick Goodfriend/Air Force)WASHINGTON — The Pentagon is abandoning its efforts to develop a next-generation adaptive engine for the F-35 Joint Strike Fighter, according to Air Force Secretary Frank Kendall.Instead, Kendall said during a March 10 briefing on the fiscal 2024 budget, the military will stick with and upgrade the F-35’s current engine — a major win for F135 maker Pratt & Whitney.The decision means the military will not move forward with its Adaptive Engine Transition Program, an...…A Pratt & Whitney F135 engine undergoes ground testing at Arnold Air Force Base in Tennessee. (Rick Goodfriend/Air Force)WASHINGTON — The Pentagon is abandoning its efforts to develop a next-generation adaptive engine for the F-35 Joint Strike Fighter, according to Air Force Secretary Frank Kendall.Instead, Kendall said during a March 10 briefing on the fiscal 2024 budget, the military will stick with and upgrade the F-35’s current engine — a major win for F135 maker Pratt & Whitney.The decision means the military will not move forward with its Adaptive Engine Transition Program, an...WW…