ST. LOUIS — With 25 hr. of flight time on new, stealthy F/A-18 fuel tanks and more trials planned, Boeing is now focusing its demonstration and marketing efforts for a host of Super Hornet upgrades toward the U.S. Navy customer, a major reversal.

“This is no longer something we consider to be just an international play,” says Paul Summers, Boeing’s F/A-18 and EA-18G director. The upgrades “fit the domestic market better right now,” says Mark Gammon, program manager for Super Hornet and Growler advanced capabilities.

The upgrade project began under the nebulous F/A-18E/F “International Roadmap” moniker, with a 2010 rollout of a menu of improvements for the twin-engine fighter. The company briefed the capabilities with foreign customers, showcased them at air shows abroad and also kept the Navy in the loop — as a courtesy, officials say.

Until now, Boeing officials have been quick to correct anyone suggesting the Super Hornet improvements were ultimately trained on its largest Super Hornet customer, the Pentagon.

Despite funding pressure in the Defense Department, the Navy appears to be on board with the concept, though funding has yet to emerge. The service is allowing Boeing to lease one of its new Super Hornets for demonstration flights and requesting some specific design tweaks — such as improved fuel load in stealthy fuel tanks. Industry officials on the Super Hornet industry team suggest funding could come as early as the 2016 budget, which will be crafted next summer.

The Navy’s interest comes as the service continues its cautious support of the F-35C project. While the Marine Corps plans to declare initial operational capability (IOC) by December 2015 and the Air Force plans for it a year later, the Navy is more measured with its intention for an IOC in 2019. Boeing officials stopped short of suggesting the Advanced Super Hornet — with its operational engine upgrade, frontal-aspect stealth improvements and situational awareness adds — could be an alternative to its rival made by Lockheed Martin. Summers notes, however, that the upgrades are designed to address the predicted threat environment in 2030 and beyond.

The entire menu of upgrades could be developed for less than $1 billion, says Mike Gibbons, vice president of the Super Hornet and Growler programs for Boeing. If the service were to buy new F/A-18s with the upgrades, the cost would be roughly about $56 million, or 10% higher than the most recent flyaway cost in the third multiyear buy cited by the company of $51 million (this price includes the aircraft, both engines and electronic warfare gear).

Though not discussed by Boeing officials, the company is likely to heavily incentivize the Navy’s interest in new build aircraft in an effort to get the service to pursue the strategy used by the Australian Air Force of delaying F-35 purchases in favor of an F/A-18E/F gapfiller. But the capabilities also can be retrofitted into existing Super Hornets with relatively little destructive work needed on the aircraft. Likely the most substantial addition would be new plumbing needed for the CFTs.

“We didn’t chase this specific set of technologies because of the F-35,” Gibbons told reporters during an Advanced Super Hornet briefing here. “Affordability is the key differentiator for us.”

The first upgrades to be flight tested are the aerodynamic qualities and radar-cross section performance of two conformal, top-mounted fuel tanks as well as a low-observable, centerline mounted internal carriage weapons pod. Boeing has leased a U.S. Navy Super Hornet fresh off the production line for these trials. The demonstrator aircraft includes about 100 lb. of radar-absorbing or scattering coatings at specific locations on the platform as well as the dummy CFTs and weapons pod.

The upgrades designed for low observability — including the CFTs, weapons pod and a redesigned radar blocker for the engine inlet — will deliver a 50% improvement over the current Super Hornet’s frontal aspect low observability, Gibbons says.