Boeing is “fairly complete” with designing the platform it proposes for the U.S. Air Force’s new Joint Surveillance Target Attack Radar System (JStars), a 737-700 Boeing Business Jet with military modifications. The manufacturer is preparing for a preliminary design review by the service next spring.

"We’re running through the risk reduction effort now, to show the government that this is a low-risk platform and a low-risk integration effort on our part,” said Rodney Meranda, Boeing JStars capture team lead. Overall, the 737-based platform will be cheaper to operate than smaller business jets proposed by rivals, he told AIN.

On November 18, Boeing provided reporters with a virtual reality tour of the JStars proposal at its Arlington, Va., facility. The manufacturer has already conducted the demonstration for Air Force personnel at Robins Air Force Base, Ga., home of the JStars 461st Air Control Wing, at the Air Force Association conference in September and other locations, executives said.

The Air Force awarded pre-engineering and manufacturing development (EMD) contracts to Boeing, Northrop Grumman and Lockheed Martin in August to perform system requirements analyses for its JStars recapitalization program to replace the E-8C JStars, which is based on the Boeing 707-300. Northrop Grumman, the current E-8C contractor, is proposing a replacement system based on the Gulfstream G550 business jet. Lockheed Martin is proposing one based on the Bombardier Global business jet. The intent of the pre-EMD contracts is to advance the proposals to the preliminary design review stage.

In September, the Pentagon’s Defense Acquisition Board withheld approving a “Milestone A” decision to launch the program’s next, technology maturation, phase. However, the board allocated funding to continue the risk reduction effort into next year, said Meranda, who added that Boeing expects the Milestone A approval in the next few weeks. The manufacturer expects the Air Force will issue a draft request for proposals (RFP) by the end of the calendar year and a formal RFP in the fourth quarter of Fiscal Year 2016, or by next September. The contract award would follow in early 2017.

Boeing has not chosen a supplier for the main, ground radar sensor of its JStars proposal. “We’re open to a lot of different companies because the requirements haven’t been finalized and we’re about nine months out from EMD,” Meranda said.

For the JStars host platform, Boeing is applying modifications that have already been incorporated on the U.S. Navy’s P-8A Poseidon maritime patrol aircraft, which is based on the 30-foot-longer 737-800, and on the Royal Australian Air Force’s Wedgetail airborne early warning and control aircraft, a 737-700. As seen through a virtual reality headset, the proposed new JStars has an in-flight refueling receptacle atop its forward fuselage. Each of two CFM56 engines is equipped with a 180 kVA integrated drive generator to provide electrical power to the aircraft, distinguished by a bump on the engine cowling. The cabin interior features 10 mission stations on seat tracks that can be rolled on and off the aircraft. Similarly, secondary mission consoles are affixed to wall tracks.

The interior of the aircraft also incorporates Boeing 787 pilot seats and 777 crew rest stations. To ease the Federal Aviation Administration civil certification process, Boeing intends to maintain the standard 737 avionics suite.

At one point in the virtual reality demonstration, participants can superimpose the cabin dimensions of the Gulfstream contender on the scene, suggesting a smaller, tighter cabin environment. While this is obviously one of the manufacturer’s selling points, Boeing also argues that the 737 will be ultimately less expensive to operate than its smaller rivals.

“The 737 total operating cost is cheaper to fly than the smaller business jets,” Meranda declared. “Why is that? Because we’ve built 8,000-plus of these airplanes, so you have this long lead [advantage] with items such as spare parts throughout the world. The economies of scale of building 8,000-plus also gives you the near-term affordability, so we can be competitive both near term and long term from an affordability construct.

“The last piece of this,” he added, “is we’re not building a green 737 against a Gulfstream-type airplane or a Bombardier. We’re building a JStars airplane, so we can leverage all of our militarized capability and integration expertise that we’ve already done on this.”