Gulfstream and Northrop Grumman are making their case for hosting the Joint Surveillance Target Attack Radar System (JStars) on a business jet as the U.S. Air Force nears a decision on the JStars recapitalization program. The companies are proposing the Gulfstream G550 to replace the service’s Boeing E-8C JStars fleet; they face competition from Boeing, offering a system based on the 737-700 airliner, and a team led by Lockheed Martin proposing the Bombardier Global 6000 business jet as a host platform.
“The real discussion is whether or not these next-generation assets should be on a business jet or continue to be on an airliner,” said Troy Miller, Gulfstream regional vice president for military and special mission sales, during a mid-July briefing in Savannah, Georgia, Gulfstream’s headquarters. “In broad terms, we think a business jet compared to an airliner can do these missions higher, faster, farther, better [and] less expensively.”
Responding separately to an AIN inquiry, Northrop Grumman concurred that a 10-station JStars battle management command and control (BMC2) system hosted on the large-cabin, ultra-long-range G550 “can fly higher and see more to prosecute more targets without any added cost.”
The G550’s “agility and size allow it to be closer to the fight because it can base at two times the number of bases that heavy aircraft can fit in,” Alan Metzger, Northrop Grumman vice president for next generation surveillance and targeting, stated in an email. “Our Recap offering uses substantially less fuel, can generate substantially more mission on-station time while flying at threshold altitude, and provides crews with greater comfort due to the better cabin pressure than a commercial airliner would.”
Northrop Grumman expects the Air Force will select a JStars weapons system provider “sometime after late October.” The service plans to award an engineering and manufacturing development (EMD) contract valued at $6.9 billion. The EMD phase calls for the delivery of three test aircraft, with options for two low-rate initial production and 12 production aircraft over three lots, for a total of 17. Separately, the service has awarded Raytheon and Northrop Grumman contracts to develop competing designs for the JStars radar subsystem.
Miller offered a number of comparisons between a nominal narrowbody airliner and a G550. Airliners traditionally are certified to fly no higher than 41,000 feet; the G550 is certified to fly up to 51,000 feet, offering a better field of view for ground surveillance. An airliner’s maximum speed is Mach 0.82; the G550 cruises at Mach 0.85. An airliner can fly to 6,200 nm; the G550’s range is 6,750 nm.
Comparing commercial aircraft platforms, the fuel burn of an airliner is almost double that of a G550 business jet, Miller said, citing figures from the firm Conklin & de Decker of Orleans, Massachusetts. The operating cost of a G550 is $9 per nm versus just under $15 for an airliner.
Gulfstream has produced 207 business jets for government and special-missions purposes in 39 countries, including 70 U.S. government and military aircraft. Working with a prime contractor, it modifies green aircraft off its Savannah production line to accommodate mission equipment.
The companies offered the Air Force multiple configurations to satisfy the requirement of the JStars recapitalization program for an aerial refueling receptacle; of those the preferred option was a nose-mounted configuration—the same location used on aircraft including the A-10 Thunderbolt II, B-1 bomber and Air Force One, Northrop Grumman said.
The latter company has flight-tested its G550 testbed behind a surrogate tanker “with no adverse handling issues.” It has also conducted in-flight refueling of the G550 behind both KC-135 and KC-10 tankers in a full-motion simulator to evaluate flight crew field of view. “Results were excellent for both a nose-mounted and crown-mounted UARRSI (Universal Aerial Refueling Receptacle Slipway Installation),” the company said.
Northrop Grumman bases the G550 JStars testbed and a mission crew trainer at its Manned Aircraft Design Center of Excellence in Melbourne, Florida. The company says it has flown the aircraft about 500 hours each year since 2011 as it has matured its offering for the JStars recapitalization program. During that time, it has displayed the testbed and mission crew trainer at Langley, Andrews, Hanscom and Robins air force bases.
Boeing Defense has a case of its own to make about replacing aging, Boeing 707-based E-8C JStars and E-3 AWACS as well as C-135 Rivet Joint, Combat Sent, Cobra Ball, Open Skies and Constant Phoenix mission aircraft with the 737. “What we believe is that the 737-based platform is the right solution for the recapitalization of all of these aircraft moving forward,” said Jamie Burgess, Boeing Defense program manager for mobility, surveillance and engagement, during a briefing in Seattle in May.
Fleet size and parts and service availability rank high among reasons for adapting the 737, which already serves as the platform for the U.S. Navy’s P-8 Poseidon. Boeing reports delivering more than 8,000 737s with another 4,000 on order. Over 65 years, it has delivered 1,200 militarized derivatives to customers in 21 countries.
“When you think about militarizing an airplane like a 737 you don’t really lose much performance in terms of mission capability and aero performance due to considerations like weight [and] mass properties,” Burgess argued. “When you start militarizing a smaller luxury business-jet class airplane, you do start to see degradation in aircraft performance. They’re just not designed to carry as much weight for as long a mission as the 737.”
Gulfstream’s Miller would disagree. “A business jet is going to be more right-sized for these types of missions,” he said. “The airliner community routinely talks about how much bigger their aircraft is than the mission requires. They use the phrase all the time ‘that gives us room for growth.’ What 'room for growth' means is that they’re offering way more aircraft than the mission requires.
“If we concede that a business jet offers better performance and lower costs and we’re right-sized for the mission, it’s really difficult to understand why an airliner would be appropriate,” he added.