As the U.S. Navy’s Super Hornets reach the end of their planned service life, Boeing is eyeing an exhaustive overhaul that will involve structural upgrades and potentially a new stealth coating to keep the F/A-18Es and Fs relevant well into the future.
Boeing hopes to induct the first Super Hornet into a planned service life modification (SLM) program in April 2018, Mark Sears, the company’s SLM director, told Aviation Week Oct. 17. Once on contract, Boeing will begin the work necessary to extend the life of each aircraft from its 6,000-flight-hour limit by another 3,000 hr.
The work primarily will focus on structural upgrades to the airframe and certain subsystems, but also could include capability enhancements to bring the older aircraft up to the newest Block III standard, Sears said.
One option is a new low-observable (LO) coating and radar-absorbent material (RAM) improvements in certain locations on the aircraft to increase its stealth, Sears said.
“There are various degrees of LO enhancement,” Sears said of the upgrade. “We’ve played within that spectrum, but there’s certainly an LO piece of Block III.”
It is not clear just how stealthy the newest Block III Super Hornets that roll off the production line in 2020 will be compared to the fleet’s primary stealth fighters, Lockheed Martin’s F-22 and F-35. The Navy funded “advanced signature enhancements” in its fiscal 2018 budget request, but Boeing has said the Block III upgrade is not primarily focused on LO.
“At some point we drew a line that would allow us to be stealthy enough in a balanced survivable way to be effective, and that is what we think we have,” said Dan Gillian, Boeing F/A-18 and EA-18 program manager. “The F-35 is a stealthier airplane, but we have a balanced approach to survivability, including electronic warfare and self-protection.”
The Super Hornet upgrade program comes not a moment too soon for the U.S. military, which has reported alarmingly low readiness levels across its fighter fleets in past few years. On a given day, just 52% of all in-reporting Navy F/A-18s can fly, including 44% of legacy Hornets and a slightly higher portion of the newer Super Hornets, 54%. These numbers reflect just how hard the Navy has flown the aircraft over the last 15 years, according to Adm. Bill Moran, vice chief of naval operations.
In the short-term, inducting Super Hornets into the SLM will reduce the number of aircraft the Navy has available for operations. But without the SLM, those aircraft are headed for the boneyard soon anyway, Sears argued.
“SLM gives them the opportunity to go back to the fleet,” he said.
To take full advantage of the time the aircraft are in SLM, the Navy also could choose to incorporate a new advanced computing infrastructure planned for the Block III aircraft, Sears said. This package, designed to take advantage of the future carrier air wing’s sophisticated sensor architecture, includes an advanced cockpit system with a large-area display for improved user interface; a more powerful computer called the Distributed Targeting Processor Network (DTPN); and a bigger data pipe for passing information known as Tactical Targeting Network Technology (TTNT).
Most critically, this architecture will ensure the Super Hornet, EA-18G Growler electronic warfare aircraft and E-2D Hawkeye can talk to each other and pass critical threat data over the same network in combat.
Boeing’s vision for Super Hornet Block III also includes a long-range infrared sensor that will allow the aircraft to detect and track advanced threats from a distance, and conformal fuel tanks (CFT) to extend range by 100-120 nm. The CFTs are designed to replace the extra fuel tanks that Super Hornets currently sling under the wing, reducing weight and drag and enabling additional payload.
Over the course of the SLM, which is slated to run through fiscal 2028, Boeing and the Navy plan to overhaul more than 400 Super Hornets, a Boeing spokesman said. The work will take place at the company’s facilities in St. Louis and San Antonio.
Sears expects the first aircraft will take about 18 months to complete, but hopes to drive that time down to about 12 months.
There is no telling what engineers will find once they tear down the aircraft, but Boeing has prepared for that process as much as possible by opening up two “learning aircraft” in St. Louis to see if predictions match the actual condition of the aircraft.
“Having those two aircraft dedicated to SLM will give us great insight into what we can expect to see,” Sears said, though he stressed: “There likely will be surprises.”