Could the U.S.Navy Replace the F-35 With an 'Advanced' Super Hornet?
By Dave Majumdar, The National Interest
(This first appeared back in 2016.)
President-elect Donald Trump’s tweet on Dec. 22—where he stated that he had asked Boeing to “price out a comparable F-18 Super Hornet” because of the sheer expense of the Lockheed Martin F-35 Joint Strike Fighter—was met with derision by journalists and Washington’s political elite.
While it is true that no version of the F/A-18E/F will ever be able to offer an exact analogue of the F-35’s capabilities, the reaction inside the Beltway was typically biased. Trump’s statement cannot be interpreted exactly literally. More likely, the President-elect was suggesting that a variant of the Super Hornet airframe could meet many of the capabilities that the F-35 offers at a more reasonable price.
For the U.S. Navy, there is a strong argument to be made that an Advanced Super Hornet derivative could offer an 80 percent solution for a lower price than the F-35C. And while such an F/A-18 derivative would not precisely meet all of the U.S. Air Force’s requirements as embodied in the F-35A, the Super Hornet is a perfectly capable shore-based strike fighter as the Royal Australian Air Force demonstrates on a daily basis. Only the U.S. Marine Corps—with its insistence on the short takeoff/vertical landing capability found on the F-35B—would have to completely revamp its air arm in the exceedingly unlikely event that Trump were to cancel the Joint Strike Fighter program. That being said, all three flying branches would have to give up on the notion of penetrating strike and rely on standoff weapons—the F/A-18E/F is not and will never be a stealth aircraft.
The one area where no version of the Super Hornet can compete with the F-35 is stealth. Stealth more or less has to be baked into an airframe design right from the outset—no ifs or buts. However, Boeing has tested a version of the Super Hornet with a significantly reduced radar cross-section—particularly in the frontal sector. The company has also tested conformal fuel tanks that can carry 3500lbs of additional fuel and an enclosed low-observable (LO) weapons pod that can carry 2500lbs of ordnance onboard the Super Hornet that would allow the jet to fly without bulky external fuel tanks or external stores during the first day of a conflict. Those features would greatly reduce the F/A-18E/F’s visibility on radar, however, even with those enhancements, the Super Hornet will never be a true stealth aircraft comparable to the F-35. It just is not physically possible.
But the question that remains is if stealth will remain the end all and be all of survivability as Lockheed Martin and the Air Force publicly contend. The Russians and the Chinese are developing low-frequency radars that can track fighter-sized stealth aircraft that are—just by the laws of physics—optimized to defeat radars in the fire control bands (Ku, X, C and part of S). Electronic warfare will become increasingly necessary to support stealth aircraft as time goes on and as low frequency radars proliferate. “[Stealth] is needed for what we have in the future for at least ten years out there and there is nothing magic about that decade,” then chief of naval operations Adm. Jonathan Greenert said at the U.S. Naval Institute annual meeting in Washington, D.C, in 2014. “But I think we need to look beyond that. So to me, I think it’s a combination of having aircraft that have stealth but also aircraft that can suppress other forms of radio frequency electromagnetic emissions so that we can get in.”
The U.S. Air Force—despite its public rhetoric—recognizes that electronic warfare will be increasingly important as enemy capabilities continue to improve. At least a dozen Air Force pilots with experience flying stealth platforms have told me that stealth aircraft don’t go into a high threat area alone and unafraid. That trend will continue to accelerate as low frequency radars proliferate and fire control radars start moving to lower bands. “Stealth and electronic attack (EA) always have a synergistic relationship—detection is all about the signal to noise ratio. LO lowers the signal, EA increases the noise,” one Air Force official told me. “Any big picture plan looking forward to deal with emerging A2/AD threats will address both sides of that equation.”
Indeed, the F-35 does have formidable electronic attack capabilities resident within its Northrop Grumman AN/APG-81 active electronically scanned array (AESA) radar. However, while the APG-81 is capable of acting as a high-gain electronic support measures antenna and as a formidable jammer, it can only do so within its own operating frequencies within the X-band. Meanwhile, the Super Hornet and its EA-18G electronic warfare variant are also equipped with an AESA radar—the Raytheon AN/APG-79. The Raytheon-built radar has much of the same potential capabilities as the APG-81, however the Navy has not yet taken full advantage of the APG-79’s potential. But the Navy will exploit more of the radar’s potential electronic warfare capabilities in the coming years.
Another advantage that the F-35 has over the Super Hornet is its BAE Systems AN/ASQ-239, which uses a series of embedded antennas on the aircraft’s skin to provide a detailed electronic picture of the surrounding battlespace to the pilot. However, technology has not stood still during the F-35’s prolonged development. The Navy is adding the Integrated Defensive Electronic Countermeasures (IDECM) Block IV to the F/A-18, which greatly increases the Super Hornet’s electronic warfare prowess. However, Boeing could easily adopt even more sophisticated systems for the F/A-18E/F airframe such as BAE’s ALQ-239 or a version of the forthcoming Eagle Passive Active Warning Survivability System—both of which offer fully integrated radar warning, geo-location, situational awareness and self-protection capabilities. These later systems offer capability similar to the F-35’s AN/ASQ-239—which they were derived from.
Another option for an Advanced Super Hornet derivative could be to adopt the EA-18G Growler variant’sNorthrop Grumman ALQ-218 radar warning receiver/electronic support measures/electronic intelligence (RWR/ESM/ELINT) sensor as standard equipment. The ALQ-218—as a purpose-built electronic intelligence-gathering tool—is in many respects more capable than the ASQ-239. Indeed, an electronic warfare officer onboard an EA-18G can analyze an unknown signal and jam it even if the threat is not in the aircraft’s threat library—something the lone pilot onboard an F-35 cannot do. However, the ALQ-218 system might be overkill for a fighter aircraft.
Sensors and Sensor Fusion:
While the Super Hornet does not have an integrated electro-optical targeting system (EOTS) like the F-35, it can carry advanced podded sensors. In fact, carrying a targeting pod instead of an integrated EOTS is an advantage in many cases. The F-35’s EOTS—while state of the art when the jets’ requirements were specified—is now dated technology. The F-35 Joint Program Office will address those technological issues in the JSF’s Block IV configuration in the early 2020s, but the process of upgrading individual systems onboard the stealthy new jet is much more complex than on a fourth-generation platform where a new targeting pod can simply be exchanged almost at will with the right software load.
Moreover, because there is no issue with breaking the outer moldline of the aircraft due to stealth configuration issues, jets like the Super Hornet are generally much easier to upgrade and can accommodate new sensors much more easily. One recent example is the Navy’s AN/ASG-34 long-wave infrared search and track sensor pod (mounted cleverly in a modified fuel tank), which entered into low-rate production earlier this year. The addition of the AN/ASG-34 affords the Navy new capabilities to detect and target enemy stealth aircraft and cruise missiles from long distance even in a heavy electronic warfare environment. Mounting a similar long-wave infrared sensor in addition to its existing mid-wave EOTS is much more problematic onboard something like an F-35 where designers have limited options to place a new item without compromising the aircraft’s stealth.
Meanwhile, the F-35 does hold another trump card—so to speak—but not one that is insurmountable. When development is complete, the F-35 will be able to correlate all of the data from its various sensors and data networks and then present that information in a single coherent and easily understandable display. Currently, only the Lockheed Martin F-22 and F-35 have such a capability, but the Navy is working on adding a similar “sensor fusion” system to the Super Hornet. The Navy’s Multi-Sensor Integration effort for the Super Hornet is being developed in three phases—some of which have been fielded—with the goal of developing a sensor fusion capability similar to the F-22 and F-35.
According to Navy officials, the Super Hornet’s MSI program drew lessons from both the F-22 and F-35. However, one major difference between the Super Hornet’s sensor fusion and the F-22 and F-35 is the limited capabilities of the F/A-18E/F’s current displays. Boeing, however, has an option to fit a new large 11’X19’ high-definition color display into the Super Hornet cockpit that would address that issue.
One of the advantages of an advanced fourth-generation design is that unlike stealth aircraft, designers don’t have to worry about stray transmissions compromising the aircraft’s position. The F-35 is equipped with the omnidirectional standard Link-16 data-link for permissive environments and the highly directional low probability of intercept Multifunction Advanced Datalink for high threat environments. The problem is that neither datalink offers enough throughput to transmit as much information as the F-35’s sensors generate—something the Navy is currently grappling with. Meanwhile, the Navy is investing in the very high data rate Tactical Targeting Network Technology (TTNT) datalink for the EA-18G Growler version of the F/A-18, which could easily be adopted by the rest of the Super Hornet fleet—especially as the Naval Integrated Fire Control – Counter Air network comes online.
The bottom line is that while the F/A-18E/F will never be a stealth aircraft, it could offer a less costly 80 percent solution for the U.S. Navy’s requirements. Once developed to its full potential, the Advanced Super Hornet could perform most of the missions envisioned for the F-35C except penetrating strike—it would have to rely on stand-off weapons for that mission. The U.S. Air Force wouldn’t be particularly happy, but if forced to make due with an Advanced Super Hornet, it would have to adapt however grudgingly. The Marines would simply be out of luck since a short takeoff/vertical landing variant of the Super Hornet is simply a physical impossibility. In any case, Trump’s motivation was likely to spur competition between Boeing and Lockheed Martin in an attempt to reduce the cost burden on the long-suffering American taxpayer. It probably was not a serious proposal.
Dave Majumdar is the defense editor for The National Interest. You can follow him on Twitter: @davemajumdar.