Russian Su-27 vs. NATO F-35A: Which Fighter Would Prevail in an Engagement Over the Baltics?

On August 13 two Italian Air Force F-35A fighters were scrambled to intercept Russian Su-27 and Su-24M fighters, marking the latest in multiple encounters between the new stealth fighter class and Russian combat jets. The F-35A has increasingly emerged not only as the new backbone of the American fighter fleet, but also as the primary fighter of its NATO allies, with the aircraft having won every tender on the continent in which it has competed against locally built fighters such as the Rafale and Eurofighter. Major recent wins for the program over competing NATO standard aircraft have been secured Belgium, Poland, Finland and Switzerland and the Czech Republic among others, while even in the United Kingdom and Germany which produce the Eurofighter, and have a strong interest in sustaining the program with domestic orders, the F-35 has received growing orders at the expense of the rival fighter. The fast growing numbers of F-35s deployed has made comparisons of the fighter’s capacities with those of the top fighters in the Russian fleet particularly relevant.

The F-35 was developed with a primary focus on air-to-ground missions, in particular the ability to operate in airspace that is densely protected by large numbers of advanced air defence systems. The aircraft was intended to be relatively light for a fighter of its generation, and has a single engine configuration and limited manoeuvrability as a result, in order to reduce costs and make it affordable for very large scale procurements. In contrast, the Su-27 was developed as a premier air superiority fighter, and when entering service in 1984 was considered totally unrivalled in the air-to-air domain, with a significantly more powerful sensor suite, longer range, and more advanced visual and beyond visual range targeting capabilities than its Western counterparts. The aircraft was designed to equip the elite of the Soviet fleet, and was far larger than any other fighter built for air-to-air combat in any Western air force. The two aircraft are thus very much opposites, with the F-35’s avionics, airframe materials and armaments also being among the most modern in the world today, while the Su-27’s age has left the once cutting edge aircraft increasingly out of date.

Should the Su-27 engage the F-35 in air-to-air combat, the F-35 would have an overwhelming advantage at beyond visual ranges. Although a small number of Su-27s have been modernised to the Su-27SM2/3 standard with highly capable Irbis-E phased array radars, these are fielded in more limited numbers, with the large majority using obsolete Cold War era mechanically scanned array radars. Thus although the F-35’s AN/APG-81 radar is only a little over one third as large as the Su-27’s own primary sensor, the discrepancy in sophistication, combined with the F-35’s use of much more advanced data links, passive and infrared sensors, and its much smaller radar signature and cutting edge stealth capabilities, ensure that it will detect the Su-27 very early, while Su-27s will struggle to detect it. The discrepancy in missile capabilities is also significant, with the AIM-120D equipping many F-35 units being significantly more capable than the R-27 and R-77 relied on by most Su-27s. The sensors on both the Su-27 itself and on its radar missiles are also expected to be relatively straightforward to jam for the F-35’s potent electronic warfare suite.

Despite the F-35’s many advantages, it is hindered by one significant shortcoming that could allow even older Su-27 variants to prevail in engagements under some circumstances. The F-35 is unable to accommodate visual range air-to-air missiles such as the AIM-9X or AIM-132 internally, meaning that when the fighters are configured to maintain their stealth capabilities, as they are on the vast majority of medium or high intensity combat missions, they lack a viable missile class for short range engagements. The Su-27, by contrast, was one of the first fighters in the world to operationalise visual range missiles with high off boresight targeting capabilities, namely the R-73, allowing them to engage targets without pointing their noses at time, and at extreme angles away from the nose. This combined with the Su-27’s significantly greater manoeuvrability would ensure a signifiant advantage over a stealth configured F-35 in visual range engagements. It is thus of paramount importance for NATO members operating the F-35 to ensure that kills are achieved at beyond visual ranges, as the Su-27 and the large majority of other fighters fielded by potential adversaries today would benefit from a significant advantage in visual range engagements due to the stealth fighter’s lack of a viable high off boresight targeting capability in most combat situations.