But as I mentioned before, these fuel tanks were not designed for stealth applications, and as such, compromise the F-22’s best-in-class stealth profile. And even if the tanks are dropped (as pilots would do if they found themselves in a fight), the mounting hardware for the pylon and detached plumbing for the fuel would remain, which also has a negative effect on stealth. As such, today, Raptors have to choose between range and low-observability – a trade-off that could be critical over the Pacific. 

And that’s where the Low Drag Tank and Pylon program comes in. This effort aims to not only field stealthy underwing fuel tanks that don’t have nearly the same negative effect on the Raptor’s radar return, but that also break away clean, eliminating leftover hardware that could make the F-22 easier to detect – after dropping its stealthy fuel tanks. 

The next most pressing shortcomings the F-22 faces in the 21st century are its lack of infrared search and track and helmet-cued targeting capabilities. The first is a passive means of targeting that detects and tracks the heat signature produced by enemy fighters, which can allow you to target even stealth aircraft that don’t appear on radar. This capability was envisioned as standard on all Raptors initially, but was ultimately cut from the program as a cost-saving measure. In the years since, IRST capabilities have become not just far more common, but increasingly necessary as stealth itself becomes more ubiquitous around the world. 

Giving the Raptor new (infrared) eyes

Integrating that IRST sensor into the airframe itself would be an immensely expensive endeavor, and it seems the Air Force has gotten around this issue by instead adding stealthy underwing pods that are mounted outboard of the stealthy fuel tanks. Like the fuel tanks, these sensor pods will have a negative impact on the aircraft’s overall stealth profile, though that impact is clearly mitigated via a radar-deflecting design and radar-absorbent coatings. 

Infrared Search and Track targeting capabilities have been around for a long time. In fact, the F-14 Tomcat started flying with an IRST pod mounted under its chin in 1991. Today’s IRST systems, however, are far more advanced and capable. Specifics regarding the latest and greatest IRST targeting systems are obviously limited, but it is worth noting that the F-22 program office specified in this program’s request for submissions that the Raptor’s new pod “provide long-range infrared sensing and object detection capabilities.” 

“Long range” is not a term with clearly defined parameters for this application, but there are some metrics we can look to in order to assess how promising the Raptor’s new targeting chops will be. First and foremost, a long-range sensor would almost certainly mean an ISRT system capable of spotting even stealthy threats from beyond visual range, which is generally considered to be 20 nautical miles out (roughly 23 miles). 

The Eurofighter Typhoon’s PIRATE IRST system was touted as being capable of detecting subsonic fighters at ranges of 50 kilometers (31 miles) from head-on and 90 kilometers (56 miles) with a clear view of their engines all the way back in 2008. The Russian Air Force claims similar ranges for their OLS-35 system found in aircraft like the Su-35. 

Unsurprisingly, claims out of China are significantly greater, but come with the standard lack of evidence to assess. Wang Yanyong, technical director for Beijing A-Star Science and Technology, went on record in 2021 to claim that the EOTS-89 electro-optical targeting system (EOTS) and the EORD-31 infrared search and track (IRST) system in development for China’s J-20 were capable of targeting the B-2 Spirit from behind at ranges of 150 kilometers (93 miles) and the F-22 at 110 kilometers (68 miles). 

It’s important to remember that IRST systems don’t function like radar, for better and worse. They’re considered passive sensors, meaning they don’t broadcast any energy to be detected by adversary fighters, but they’re also limited by atmospheric conditions and a litany of other environmental factors. 

While we tend to talk about IRST systems individually to highlight the implications of their use, the real value is found through integrating IRST systems with radar and other onboard sensors to create a more robust targeting image of the battlefield – using different forms of detection and targeting to offset adversary countermeasures and improve the likelihood of a successful engagement. 

Unlocking the full capabilities of weapons like the AIM-9X

And while on the topic of targeting, the F-22’s lack of helmet-cued targeting is perhaps its most glaring shortcoming on the modern stage. Today, the Raptor is the only front-line fighter in the American arsenal that lacks this ability, forcing F-22 pilots to actually orient the nose of their aircraft at their opponent to lock on and fire. Of course, thanks to the Raptor’s insanely powerful AN/APG-77V1 active electronically scanned array radar and its stealth, this can usually be done from 60+ miles away without the adversary fighter even being aware of the F-22’s presence, but it nonetheless represents a shortcoming in the fighter’s pilot interface. 

 

While little is known about the helmet-cued targeting capabilities believed to be making their way toward service in the F-22, we know the Air Force was testing a modified version of the Thales Scorpion HMD in the Raptor as far back as 2014, and while there has historically been clearance issues with the Raptor’s uniquely shaped canopy, it seems like an engineering nut the Air Force would be eager to crack, and indeed, they may have with the Next Generation Fixed Wing Helmet program that saw testing in the Raptor last year. 

The addition of helmet-cued targeting would allow the Raptor to take full advantage of modern weapons like the AIM-9X, which is famously so maneuverable that it can engage adversaries flying behind the launching aircraft, but until F-22 pilots can target these aircraft using their line of sight, this high-off-boresight targeting capability remains untapped in the Raptor. 

The addition of IRST, helmet-cued targeting, and stealthy fuel tanks alone will represent a massive leap forward in F-22 capabilities, but these are really just the most conspicuous changes to the Raptor. Much of the rest of the ongoing multi-billion dollar upgrade lies beneath the fighter’s radar-absorbent skin, including new encrypted communications systems and a bevy of other new sensors being integrated into the F-22 as a bridge toward the NGAD fighter slated to replace it. 

Bringing the F-22 into the 21st century

One of the more secretive additions to the F-22 is the introduction of the new Government Reference Architecture Compute Environment, or “GRACE.” This open-system software architecture will improve processing power, pilot interface capabilities, and even allow the aircraft to adopt software that wasn’t originally designed for the Raptor. 

Another new system being bolted onto the Raptor is the Northrop Grumman-led Embedded Global Positioning System (GPS) / Inertial Navigation System (INS) Modernization, also known as the LN-351 EGI-M. This advanced navigation system takes advantage of the Air Force’s newest and most modern GPS III satellites which can transmit directly to the aircraft via high-gain directional antennae that are encrypted and extremely difficult to jam or spoof. This, in conjunction with an updated inertial guidance system that can function with high degrees of accuracy with only intermittent or limited access to GPS signals will allow F-22s to operate freely in GPS-denied environments. 

Other new systems include the Mode 5 Identification Friend or Foe (IFF) transponder, which is rapidly becoming standard across NATO air forces. This military-specific identification system uses allows for what the Pentagon describes as a secure and encrypted data exchange through use of the new waveform, making it easier than ever to discern between friendly and enemy aircraft at a distance. The Mode 5 IFF integrates seamlessly with surface-based air defense systems like Patriot and AEGIS, and as a “lethal interrogation format” transponder, can even receive responses from friendly transponders that are set to “standby,” further limiting the chances of friendly fire in beyond-visual-range engagements. 

There has even been mention of upgraded avionics making it possible for F-22s to fly alongside AI-enabled drone wingmen, just like the forthcoming Block 4 F-35 and Next Generation Air Dominance Fighter. This alone could have a massive impact on the F-22’s combat capacity, further bridging the gap between the oldest 5th generation fighter in the world and the forthcoming 6th generation of jets. 

Other upgrades to the aircraft’s operational flight program, electronic warfare capabilities, and communication systems have also been listed in Air Force budget documents, but details regarding their improvements remain few and far between. Overall, the F-22 fleet is expected to receive roughly $7.9 billion in upgrades by 2029, and by October 31, 2031, that figure is slated to reach just under $10.9 billion. 

To put that figure into context, the F-22 upgrade budget is enough to purchase 132 new F-35As and still have enough left over for a very comfortable retirement. In terms of the 150 combat-coded F-22s in America’s stable, that shakes out to roughly $72.6 million in upgrades allocated to each individual Raptor.