Gross Issue Effectiveness (GIE) and Supply Response Time (SRT) for the on-time delivery of required spare parts are to be  key features of a Performance-Based Logistics contract that the F-35 program may initiate this year for the Lockheed Martin [LMT] fighter. Quality GIE and SRT ratings may reflect significant savings, yet overcoming lingering supply chain problems looks to be an issue for the F-35 and other aircraft and weapons programs.

“When it comes to spares, this is one of the most pronounced impacts that we’re seeing, as we continue to work through workforce and supply chain issues,” Air Force Lt. Gen. Richard Moore, the Air Force’s deputy chief of staff for plans and programs, said at Mitchell Institute for Aerospace Studies virtual forum on Apr. 6. “When we finished the submission of our [Air Force fiscal 2024] budget to the Department of Defense last July, we funded 1.1 million flying hours. In order to maintain that same 1.1 million flying hours, when we closed out the President’s [fiscal 2024] budget in February to submit it to the Office of Management and Budget, the cost of the flying hour program had gone up by 10 percent. Almost all of that was in spare parts. So in nine months the cost of the flying hour program grew by 10 percent.”

The Air Force’s more than $8 billion flying hour request for fiscal 2024 includes nearly $6.7 billion for the active Air Force and about $1.5 billion for the Air National Guard. The increase in spare parts cost also affected the Air Force’s fiscal 2024 request for $18 billion in weapons sustainment, the service said.

“Readiness hinges on the ability to operate, maintain, and sustain an aging fleet of aircraft while funding the flying hour program,” per the Air Force’s fiscal 2024 budget request. “Weapons system sustainment requirements—funded at 87 percent—continue to grow due to aging platforms and the acquisition of new, highly technical, and complex weapons systems.”

In fiscal 2023, the Air Force requested almost $5.9 billion in operations and maintenance for the active duty flying hour program, and the fiscal 2023 omnibus last December appropriated nearly $6.5 billion–a 10 percent increase.

The fiscal 2024 Air Force budget called out “cost per flying hour elements” as responsible for $516 million in cost growth for the active duty Combat Air Forces (CAF) flying hour program for fighters, bombers, combat search and rescue, and reconnaissance planes.

“The CAF flying hour program reflects a program funding net increase and an increase of 17,002 hours,” per the budget request. “The program funding net increase is due to an increase in price in the cost per flying hour elements (i.e. fuel, parts, and supplies). The following is a detailed breakout of the changes in hours by aircraft: A-10C (2,507 hours), B-1B (687 hours), B-2A (45 hours), B-52H (-652 hours), HC-130J (1,318 hours), E-3G (-503 hours), E-4B (8 hours), E-8C (-95 hours), E-9A (-18 hours), E-11A (2,460 hours), F-15C/D (-17,353 hours), F-15E (13,106 hours), F-15EX (4,200 hours), F-16C/D (535 hours), F-22A (-2,809 hours), F-35A (13,064 hours), HH60G (215 hours), HH-60W (550 hours), RC-135S/U/V/W (78 hours), T-38A (-326 hours), and TC-135W (-15 hours).”

Moore said on Apr. 6 that one of the biggest challenges that the Air Force will face in the FY 2025 budget cycle is “how do we keep up with these large accounts [like the flying hour program and weapons sustainment], as they continue to grow faster than inflation?”