Boeing Might Include Stealthy Features on Overhauled US Navy Super Hornets

The service life extension program will give the jets thousands more flight hours, but could include other upgrades.

MSF13-0081
Boeing

Boeing has disclosed that the expected service life extension program for the U.S. Navy’s F/A-18E/F Super Hornets could include stealth features and improved avionics and mission systems in addition to a more general airframe overhaul. This more comprehensive update would not only keep the aircraft safely flying at least until 2040, but could potentially make them a capable, but low-cost alternative in many scenarios compared to the service’s up-coming F-35C Joint Strike Fighters or any future sixth generation design.

On Oct. 17, 2017, Mark Sears, director of Boeing’s Super Hornet service life modification (SLM) division, told Aviation Week that the company hoped to begin work on the first of the Navy’s aircraft in April 2018. The basic overhaul would add approximately 3,000 flight hours of service life to the jet’s existing 6,000 hour life span, in line with stated plans to keep the planes in service through 2040. In addition, the program may include additional improvements, including unspecified low observable (LO) or stealthy enhancements, to bring the service’s existing aircraft closer to the configuration of the all-new Block III F/A-18E/Fs it is also planning to buy.

“There are various degrees of LO enhancement,” Sears explained to Aviation Week without giving detailed specifics. “We’ve played within that spectrum, but there’s certainly an LO piece of Block III.”

In general, Sears said these possible additions could include adding a low observable material “coating” to the basic airframe or replacing existing portions of the aircraft with radar absorbent material components. A fully enclosed weapons pod or similar conformal compartments might be an easier addition. It would be difficult for the Navy to request drastic changes to the basic shape of the plane without incurring significant additional costs.

Boeing

Boeing's Advanced SUper Hornet prototype with conformal fuel tanks and a fully enclosed weapons pod.

In 2015, pictures did begin toemerge of what appeared to be a Super Hornet test article with a dramatically revised planform sitting in storage at the U.S. military’s main aircraft Bone Yard at Davis-Monthan Air Force Base in Arizona. This could be part of what Sears meant when he said Boeing had “played within that spectrum,” but he also suggested to Aviation Week that the company had eventually decided to take a significantly less labor intensive approach.

“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.”

Beoing first proposed an "Advanced Super Hornet" upgrade in 2008. The new Block III configuration will reportedly include a long-range infrared search and track (IRST) sensor, already in the works as part of the Block II upgrade, that can detect the heat signature of enemy aircraft. This would complement the F/A-18E/F’s already capable AN/APG-79 active electronically-scanned array radar, which the Navy introduced with the Block II aircraft and subsequently added to its older Super Hornets. 

On top of that, Boeing’s Block III fighters feature a new widescreen cockpit display, an improved mission computer, and data links that can receive and transmit more information to and from the aircraft to improve the pilot’s overall picture of the battlefield. The Navy has plans for an overarching data sharing network, called Naval Integrated Fire Control-Counter Air, or NIFC-CA, which will link its ships, manned aircraft, drones, and other sensor nodes, as well as networked missiles and other stand-off munitions themselves, together.

Beyond just providing greater situation awareness and integrated threat information from E-2D Hawkeye airborne early warning planes and EA-18 Growler electronic warfare aircraft, the links would allow ships or aircrafts to pass targeting information to other assets, or even networked missiles or other munitions themselves. An F/A-18E/F integrated into the NIFC-CA net could, in theory, fire a long-range air-to-air missile at a target using the radar picture from a drone scouting ahead or a ship operating in the area, allowing the aircraft to engage the enemy even while in "radar silent" mode, helping to conceal its own position.

Boeing

An look at possible Advanced Super Hornet enhancement from a presentation about the IRST upgrade.

The other major reported addition to the Block III Super Hornets is a set of conformal fuel tanks (CFT) that will add approximately 100 to 120 miles to the jet’s effective combat radius of around 450 miles, depending on its load. The CFTs would also take the place of two drop tanks that the jets often carry on operations, potentially freeing up more space for ordnance. Further improvements in the future could include enhanced performance General Electric F414 engines with roughly 20 perfect more thrust, as well.

The Navy hopes its up-coming MQ-25 tanker drone will allow the carrier air wing to strike targets another 500 miles further away by itself. This means that Block III Super Hornets with CFTs coupled with the MQ-25 could possibly hit enemy positions more than 1,000 miles away from the carrier, keeping the ship safer from the increasing danger of networked defenses and long-range anti-ship missiles, including anti-ship ballistic missiles.

Combined with any low observable additions, both the new Block III jets and the overhauled aircraft could offer the Navy more options when planning operations against medium-to-high end threats. While the improved Super Hornets wouldn’t be able to take the place of the F-35C Joint Strike Fighters against a layered, integrated air defense network on the “first day” of a conflict, it might make them more survivable against any residual threats that remain after the initial strikes. 

In the open sorties of a crisis, the enhanced F/A-18E/Fs might even be able able to use their new low observable features and other countermeasures to get close enough to the target area to safely launch stand-off weapons. It would also increase the number of lower risk situations in which F/A-18E/Fs might be able to fill in for stealth F-35Cs, helping reduce the operational burden on those jets.

Regardless of how intensive Boeing’s SLM division expects the upgrade work to be, the Navy is in desperate need of the basic overhauls to prevent a dangerous fighter shortfall. On average, less than 60% of the service’s Super Hornets are flyable every day. That figure is even lower when looking at totals for both the older F/A-18A/B/C/D Hornet fleet and the F/A-18E/Fs combined. A spate of accidents and vexing problems with the aircraft’s on-board oxygen generation system (OBOGS), another issue we at The War Zone have previously looked at in detail, undoubtedly haven’t helped those statistics.

The Navy will have to decide whether or not a more extensive upgrade is worth it, both in terms of cost and time the aircraft will be out of service. It is possible that Boeing could interest other Super Hornet operators and potential operators in the package, as well, which would help drive down the final unit price.

USN

A US Navy F/A-18E Super Hornet.

Boeing’s Mark Sears told Aviation Week that the company expected the overhaul of the first Super Hornet would take approximately 18 months, though he did not say whether this was the time frame for the SLEP or that plus additional Block III upgrades. He added that he hoped his team could shorten this down to just a year, but noted that there would “likely be surprises.”

The Navy is likely hoping to avoid a repeat of service life extension work on its older F/A-18C/D Hornets, which began in 2012. That work suffered significant delays as depots began pulling planes apart and discovering a host of unexpected problems. Boeing told USNI News in April 2017 that it had adopted a different and more extensive “factory production approach” to get ready for the Super Hornet program.

The Chicago-headquartered plane maker expects to put more than 400 Super Hornets through the process, which will run through 2028. The Navy’s budget request for the 2018 fiscal year includes $87 million specifically for the project, but does not explain how many planes this money will cover.

Without the work, many of the jets in question are headed to the bone yard sooner rather than later as is, Sears noted to Aviation Week. The Navy has gobbled up hours on these jets over the last decade and a half of fighting in the Middle East and other high-tempo operations abroad. 

We may just have to wait and see what the rehabilitated Super Hornets look like when they emerge from Boeing’s St. Louis, Missouri and San Antonio, Texas facilities, and if they have obvious stealth additions or not.

Contact the author: jtrevithickpr@gmail.com