A Look at America’s New Jet Via Its Competition

Widely considered to be the least stealthy of the world’s fifth-generation competitors, the Su-57 Felon likely trails behind the J-20 in terms of observability—but that could be by design. The F-117 Nighthawk marked America’s transition away from the Cold War priorities of faster and higher-flying jets. Instead, new and costly technologies would defeat air defenses by avoiding detection altogether. Russia’s troubled economy and aging industrial infrastructure may be limiting the nation’s ability to develop the material science and tight production tolerances required of a truly “stealth” fighter.

“I would handicap the Su-57 as something between an International Roadmap Super Hornet or Silent Eagle and China’s J-20, with it being closer to the former than the latter,” aviation analyst Tyler Rogoway explained.

But recent images of the second production Su-57 in progress suggests that production tolerances have improved over the dozen previous fighters to roll out of Russia’s Komsomolsk-on-Amur Aircraft Plant.

“The tolerances on the skin panels here are significantly better than what we saw on the 11 pre-production aircraft,” Aviation Week defense editor Steve Trimble said upon the release of Russia’s second production Su-57.

While there remains some debate about how stealth China’s J-20 truly is, it is still believed to be more difficult to detect than its Russian competition. As is the case with the Su-57, experts can only speculate about the makeup and capability of the radar-absorbent materials coating on these fighters.

The J-20 was heavily influenced by stolen design schematics for America’s F-22 Raptor, though there are some clear differences between the two aircraft. The J-20’s front canards were initially thought to be a detriment to the aircraft’s stealth profile, but computer modeling would seem to suggest that the J-20 is likely extremely difficult to detect when approaching head-on and could further improve its stealth profile as the program matures.

“If the production J-20 introduces a rectangular faceted nozzle design, and refinements to fuselage side shaping, the design would present very good potential for robust Very Low Observable performance in the S-band and above,” wrote Dr. Michael J. Pelosi and Dr. Carlo Copp in an in-depth 3D modeling study of the fighter.

S-band and higher radar frequencies are used to capture a weapons-grade lock on an aircraft.

Russia’s Su-57, like America’s F-35, is capable of exchanging data with other nearby aircraft and ground assets, which it couples with existing intelligence about known targets to offer a streamlined understanding of the battle space.

“The avionics on the Su-57 fighter is based on the entirely new architecture, which, to date, has never been used in Russian military aviation,” explained Dmitry Gribov, a chief designer of the Su-57’s onboard systems. “It is operated on the concept of network-centricity, which involves a consistent upgrading of onboard systems and operating complexes of the aircraft. The multi-core base of the complex provides almost unlimited possibilities.

“The Su-57 also boasts side-facing radars that work in conjunction with its nose-mounted X-Band N036 Byelka (Squirrel) AESA radar system. These cheek-mounted radars offer the Su-57 an extremely wide field of view and dramatically enhances the pilot’s situational awareness.”

The J-20, like the Su-57 and other fifth-generation competitors, is believed to leverage a secure data link for advanced communications and data transmission between it and other aircraft and nearby ground assets.

The J-20 also boasts a chin mounted infrared/electro-optic search-and-track sensor and a passive electro-optical detection system that offers the pilot a high degree of situational awareness of everything going on around the aircraft in a 360-degree sphere. These systems are rumored to be advanced enough to be on par with the advanced systems employed by the F-35, the U.S.’s “quarterback in the sky.”

Onboard systems combine radar information with infrared imaging to offer the pilot an integrated view of the battle space via holographic heads-up display and LCD touch screens. The primary screen in the J-20’s cockpit is 24 inches by 9 inches with three smaller auxiliary displays.

Like the competition, the Su-57 carries its weapons internally to maintain a minimal radar profile. Details remain fairly limited regarding the Su-57’s armament, but there are a few things we can assess for certain. The Felon leverages a unique internal weapons bay configuration that can likely support between four and six medium-range air-to-air missiles. Two secondary weapons bays can also be found in triangular structures located under the fighter’s wing roots that open like clamshells to reveal short-range air-to-air missiles. Thus far, no images or footage of these unique secondary bays in use have surfaced.

The aircraft also boasts six external hardpoints for carrying extra munitions when stealth isn’t a concern.

The Su-57 employs a single 30mm Gryazev-Shipunov GSh-30-1 autocannon for close-range engagements. While the Su-57 is Russia’s most advanced fighter, its cannon has actually been in service since 1980. With a firing rate of 1,800 rounds per minute and incendiary armor-piercing projectiles, this weapon can be deadly at an air-to-air range of 800 meters and an air-to-ground range of more than 1,800.

The J-20 goes about hiding its weapons from radar slightly differently than the Su-57, utilizing one large primary bay for a variety of missiles and bombs often meant for air-to-surface engagements, as well as two smaller lateral bays used specifically for air-to-air weapons. The lateral bays allow the J-20 to keep its primary weapons bay closed while engaging other fighters, minimizing the jet’s radar signature even while it engages airborne opponents.

But the J-20 was not designed for close-up dogfighting and was instead intended to engage enemy aircraft from longer ranges. As such, the aircraft has no cannon whatsoever, making it the only fifth-generation fighter in service anywhere in the world that has opted to forgo the guns.

When stealth isn’t a concern, the J-20 also boasts four additional external hardpoints beneath its wings. In total, the aircraft can carry four weapons in its primary internal bay, one in each lateral bay, and four externally.

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While Russia may struggle with the tight production tolerances required of a stealth airframe, there’s no denying the nation’s knack for developing highly maneuverable fighters. Like the acrobatic fourth-generation Su-35, the Su-57 utilizes 3D thrust vectoring controls that allow the aircraft a great deal of maneuverability at high speeds and altitudes.

Thrust vector controls allow the pilot to direct the outflow of thrust from the engines independent of the direction the aircraft itself is pointed. This allows the Su-57 to execute dramatic rolls and loops at low speeds, though doing so scrubs a great deal of the aircraft’s momentum and may leave it susceptible to attack from other nearby fighters. As such, thrust vector controls would most likely be leveraged for attacks at high altitudes and speeds. It can orient the fighter’s nose down toward enemy aircraft while its engines’ outlets keep it traveling in a forward direction.

While the F-22 Raptor also utilizes some degree of thrust vectoring, the Su-57 is the only stealth fighter on the planet to incorporate 3D (or omnidirectional) thrust vector control.

The first J-20s in service to China’s air force did not incorporate thrust vector controls, but China announced that their latest iteration of the fighter, the J-20B, will include the capability. Some experts think that the J-20’s length and aerodynamic profile make it poorly suited for the sort of acrobatics required of an air superiority fighter, but reports out of China seem to suggest that it’s not as clumsy as some experts may believe.

J-20 test pilots have been quoted as saying that the aircraft was comparable in agility to China’s acrobatic fourth-generation fighter, the J-10. Another analysis from Chinese aerospace engineer Dr. Song Wencong also suggested that the jet would be more agile than what many experts predict.

But simply saying the aircraft is highly maneuverable isn’t the same as building a highly maneuverable aircraft, so the J-20’s acrobatic chops remain in question.

While some may question the Su-57’s stealth, there is little doubt that the aircraft itself is a solid performer. The Su-57 is expected to field new Izdeliye 30 engines in the future, but even with the less powerful AL-41F turbojet engines that current Felons operate, the fighter is capable of speeds in excess of Mach 2, with a service ceiling of 66,000 feet, and a rate of climb of 1,180 feet per second.

Its powerful engines combined with thrust vector controls make the Su-57 both a speedy and an acrobatic adversary. While exact figures regarding the fighter’s range vary depending on the source, it is believed that the Su-57 has a supersonic range of more than 900 miles, or 1,900 miles while traveling at subsonic speeds and carrying external fuel tanks.

The Su-57 also boasts directional infrared countermeasure systems that use laser turrets to blind incoming infrared missiles, and the fighter jet was designed with robust enough landing gear to utilize austere and poorly developed airfields.

All told, the Su-57 may not be the best fifth-generation fighter on the block, but does appear to be a well balanced and capable aircraft that would be a fierce opponent for nearly any fighter in the sky.

When compared to the Su-57, the J-20 looks pretty good on paper. While China is also struggling with developing a tailor-made engine for its fifth-generation fighter, J-20s operating Russian-designed AL-31 engines still boast an impressive top speed of Mach 2.55. Intended to serve as a long range interceptor, the J-20 is believed to have a range of more than 1,600 miles, placing it well ahead of its Russian competition.

Like the Su-57, the J-20 tops out at around 66,000 feet, but it will get there a bit slower than the Felon thanks to a climb rate of just below 1,000 feet per second.

Despite being faster and having a longer range, concerns about the J-20’s agility would likely place it behind the Su-57 in terms of close-range dogfighting capabilities, as does its lack of onboard cannon. But defense experts don’t agree on how practical close range dogfighting really is in the 21st century, so it’s difficult to say if the decision to omit the cannon will come back to haunt the Mighty Dragon.