While COVID-19 affected the supply chain for BAE Systems‘ B-Kits for the company’s Eagle Passive Active Warning and Survivability System (EPAWSS), the U.S. Air Force said that it expects deliveries to be back on schedule by this fall.

“There are 19 B-kits actively in production and the first three are late but are not delaying F-15EX deliveries or F-15E modifications,” the Air Force said on May 18 in an email response to questions. “The primary reason the initial B-kit hardware modules are behind schedule is because of post-COVID global supply chain issues.  BAE Systems completed production of the initial developmental test hardware in 2020 and is now re-energizing the supply base.  The production schedules will improve over time, as BAE Systems is confident in their ability to recover and get back on schedule this fall. B-kit hardware consists of 16 Line Replaceable Units (LRUs) installed throughout the airplane. The USAF, Boeing, and BAE are actively managing the manufacturing process to ensure hardware is in place to support F-15EX production and F-15E modification requirements.”

The Air Force awarded a $478 million engineering and manufacturing development contract for EPAWSS in November 2016.

“BAE’s ability to deliver B-kit hardware has been consistently behind schedule throughout the EMD contract,” according to a Pentagon Selected Acquisition Report (SAR) last year. “With the planned purchase of F-15EX EPAWSS systems, the need for initial spares, and the potential for retrofitting certain EPAWSS components, not all EPAWSS kits produced by BAE will be allocated to the EPAWSS program lot buys. If BAE is unable to increase its hardware production capacity to the level of demand required by the EPAWSS program and the F-15EX program, it is likely that EPAWSS installation throughput at San Antonio and Warner-Robins [Air Logistics Complexes] will be limited by availability of hardware, lengthening the time period in which those installations occur. This will cause the average cost per install to increase at each location.”

EPAWSS is to replace the F-15E’s Northrop Grumman [NOC]-built Tactical Electronic Warfare System self-protection suite, a 1970s-era system that is “functionally obsolete” and costly to sustain, the Air Force has said. EPAWSS is to allow the detection, identification and geolocation of Radio Frequency (RF) threats as well as the defeat of adversary electro-optical/infrared systems “in contested environments with dense RF backgrounds,” the SAR said.

Air Force plans call for 99 Boeing [BA] F-15E fighters and 104 F-15EXs to carry EPAWSS–a reduction of one-third, due to the Air Force’s planned retirement of more than 100 F-15E Strike Eagles in the coming years (Defense Daily, Apr. 26).

BAE Systems, which builds EPAWSS in Nashua, N.H., said last month that the company “has delivered EPAWSS hardware to Boeing and looks forward to further demonstration of the system’s advanced capabilities at the Northern Edge 2023 test event.”

Air Force acquisition chief Andrew Hunter approved low-rate initial production (LRIP) hardware installation of EPAWSS on 43 F-15Es last June.

The first two LRIP installations of EPAWSS on the F-15E “started in June and July 2022 respectively and are projected to complete in the fall of 2023,” the Air Force said in its email response.

The Air Force said it expects to complete the final LRIP EPAWSS installation in 2026.

The EPAWSS program is envisioned as two increments.  The first is to replace the radar warning receiver, internal countermeasure system and countermeasure dispenser, while the second is to include a towed decoy and mono-pulse angle countermeasure. The ongoing Increment 1 work is to cost $3.5 billion, while a start for Increment 2 is uncertain.

EPAWSS’ estimated unit cost is $11.7 million, the Air Force said.

Last year’s Pentagon SAR report named two performance issues that the Air Force said it has almost fully resolved–a misidentification of some signals from the background RF environment as threats, a “mis-ID” common for all EW systems, according to the SAR report, and EPAWSS not meeting a Capabilities Development Document (CDD) key system attribute for low-band direction finding performance for all threat systems. Last year’s SAR report said, however, that Air Combat Command judged EPAWSS’ low-band direction finding performance as “operationally useful” and thus “accepted performance as is.”

“EPAWSS previously mis-identified some background signals as threats because of the sensitive nature of the hardware,” the Air Force said in the May 18 email response. “As expected, misidentification was a challenge during the developmental phase of the program, but the program aggressively managed the issue and BAE Systems improved system performance over time.  The latest test event at the Air Force Research Laboratory Integrated Demonstrations and Applications Laboratory (AFRL IDAL) in February 2022 demonstrated improvement in misidentification and the program subsequently closed this issue.  EPAWSS performance meets the USAF specifications for radar warning and system identification. The USAF spent approximately $3 million specifically to improve performance in this area.”

On June 27 last year, the Air Force “approved an updated CDD to address low-band direction-finding performance,” the Air Force said.

The F-15E has been a workhorse in Air Force operations. In March, two Strike Eagles struck Iranian-backed militia targets in Syria, the Pentagon said (Defense Daily, March 24).

Combat aircraft receiving the biggest requested flying hour increases in fiscal 2024 are the Strike Eagle–13,106 hours, the Lockheed Martin [LMT] F-35A–13,064 hours, the F-15EX–4,200 hours, and the A-10–2,507 hours. The Air Force requests 17,353 fewer hours in fiscal 2024 for the F-15C/D fleet, which the service wants to retire.

In fiscal 2024, the Air Force requests more than $8 billion for 1.1 million flying hours (Defense Daily, Apr. 6).