The U.S. Air Force on December 28 released a request for proposals (RFP) for the development phase of its program to replace the Joint Surveillance Target Attack Radar System (JStars) hosted on the Boeing E-8C aircraft. The service expects to award a contract for the JStars Recapitalization program in Fiscal Year 2018, which begins next October.

The RFP calls for the delivery of three engineering and manufacturing development (EMD) aircraft for testing, with options for two low-rate initial production aircraft and 12 full-rate production aircraft over three lots—for a total of 17. These will replace the Air Force’s current fleet of 16 E-8Cs, which are repurposed from Boeing 707-300 series airliners. That fleet has surpassed one million flight hours, the Air Force announced in September. Developmental E-8A aircraft first served in Operation Desert Storm in 1991.

In the Fiscal Year 2017 National Defense Authorization Act signed into law by President Barack Obama on December 23, Congress specified that funds be made available for JStars recapitalization only if the Air Force awards a firm fixed-price contract for the EMD phase. Lawmakers allowed that the secretary of defense could waive the condition if the waiver was considered to be “in the national security interests of the United States.” Frank Kendall, undersecretary of defense for acquisition, technology and logistics, granted the waiver on December 23, allowing for both fixed-price and cost-plus components of the contract, Defense News reported. The estimated cost of the EMD phase is $6.9 billion.

The Air Force awarded pre-EMD contracts to industry teams led by Northrop Grumman, Lockheed Martin and Boeing in August 2015. Northrop Grumman, the current E-8C contractor, proposes a system based on the Gulfstream G550 business jet, Lockheed Martin on the Bombardier Global business jet, and Boeing on the 737-700 airliner. In March this year, the service awarded Raytheon and Northrop Grumman risk-reduction contracts for the radar subsystem to succeed the AN/APY-7 side-looking phased array radar contained in a radome beneath the forward fuselage of the E-8C. The sole-source awards required the contractors to mature their radar designs by next September.

“We’ve completed successful pre-EMD efforts with industry and continue to make progress on our radar risk reduction activities,” said Col. Dave Learned, the Air Force’s JStars Recapitalization program manager. “Thanks to the amazing work by our team, the program is well-positioned for a successful EMD phase.”