The House Appropriations Committee’s version of the fiscal 2024 defense funding bill turns back the U.S. Air Force’s proposal to cancel the Advanced Engine Transition Program (AETP) and provides $150 million for AETP, while also funding the Raytheon Technologies‘ [RTX] Pratt & Whitney F135 Engine Core Upgrade (ECU) for the Lockheed Martin [LMT] F-35 fighter at nearly $255 million.
The committee recommends moving forward on F135 ECU to accommodate the Block 4 weapons and sensor upgrades for the F-35 while also retaining AETP as an option for future F-35 blocks should the F135 ECU not meet military forces’ needs.
“The committee recognizes that the independent cost assessment completed by the Director of Cost Assessment and Program Evaluation found that fielding adaptive cycle engine technology on only the F–35A would drive unsustainable costs in future years for the Air Force,” according to the report on the bill. “The committee concurs with this finding and understands the Air Force has fully budgeted for ECU activities in fiscal year 2024 and the future years defense program. The committee fully funds the request for F135 ECU to improve the F–35 engine program.”
“Further, the committee finds the business case analysis completed by the [F-35] Joint Program Office and other analyses provided to the committee to be incomplete in assessing whether the F135 engine will meet the expected thrust and thermal management capacity requirements,” the report said. “While the committee assesses that the F135 engine may meet future needs with the planned upgrades, it also finds that continued investment in engine testing for fighter aircraft is justified.”
The F-35 program has said that it considered the F135 ECU and the General Electric [GE] XA100 AETP engine and the Pratt & Whitney XA101 adaptive cycle engine offerings in a business case analysis that informed the Air Force’s decision to cancel AETP and move forward with the F135 ECU.
The committee said that it recommends $150 million for AETP in fiscal 2024 in order to “mitigate risk for both adaptive cycle and future engine development programs.”
In addition to the $150 million to reinstate AETP, the committee provides the Air Force-requested $595 million for the Next Generation Adaptive Propulsion program for the Next Generation Air Dominance (NGAD) fighter.
NGAD received the Air Force-requested $2.3 billion for fiscal 2024 in the House Appropriations Committee’s mark up.
“The testing objectives for AETP shall align with funding provided in prior fiscal years and shall dually inform the enabling design for Next Generation Air Dominance capabilities,” the committee report said. “The committee emphasizes that this increase is not intended to incentivize the Air Force, or any other service, to create an alternative engine program for the F–35. Therefore, the act includes a general provision that prohibits the use of funds to integrate an alternative engine on any F–35 aircraft.”
The committee recommends $5.1 billion in procurement for 51 F-35As in fiscal 2024–$255 million and three aircraft above the Air Force request.
The Air Force fiscal 2024 budget includes $794 million for sensor upgrades to the Lockheed Martin F-22A fighter, but House appropriators cut that request to about $360 million–a reduction of nearly $435 million.
“The committee strongly supports the increased investment in modernizing the F–22A, which is critical to executing the National Defense Strategy,” according to the House Appropriations Committee’s report. “However, the committee is deeply concerned by the program’s developmental delays and the lack of corresponding adjustments in the fiscal year 2024 president’s budget request, despite significant reprogramming actions in fiscal year 2023.”