By Bijan Razzaghi
As fifth generation fighter designs such as the F-35 and Su-57 become operational 4th generation designs will continue to play an important role in filling up fighter squadrons throughout air forces around the world. Although fifth generation fighter like the F-35 have successfully been widely exported to both NATO and major Non NATO allies some air forces will not be able to procure the F-35 in large numbers while other might not be able to obtain 5th generations platforms at all. Export restrictions and cost will leave air forces no other choice but to procure advanced 4th generation fighter aircraft. As a result 4th generation fighters must be able to operate effectively in the dynamic 21st century threat environment. The current threat to 4th generation aircraft in the 2020s will be A2/AD (anti access and area denial) defenses such as IADs (integrated air defense systems) as well as low observable combat aircraft. As a result 4th generation designs must have have effective situational awareness and survivability.
Situational Awareness
Several systems have been interegrated into 4th generation fighters to ensure effective situational awareness, among these are AESA radar, IRST/Targeting Pods and sensor fusion. AESA radars such as the AN/APG-83 SABR and Euroradar CAPTOR allow aircraft to track multiple targets at by scanning a large area uninterrupted. AESA radar also makes it harder for RWR system (radar warning receiver) to detect the aircraft allowing for a lower probability of intercept. IRST and Targeting Pods provide additional situational awareness by allowing the pilot to detect threats based on their heat source and at times without the need to use radar. IRST systems in particular can be employed to detect low observable aircraft such as the J-20 and Su-57 from the heat of their exhaust. Sensor fusion provides the ultimate level of situational awareness by coupling data from the aircrafts radar, RWR, navigation systems and ECM systems. This data is often displayed on a single MFD providing the pilot with a perfect picture of combat area and perspective threats along set way points. Certain 4th generation fighters such as the Dassault Rafale and Saab Gripen E utilize sensor fusion. The technology has also been tested on the F/A-18 E/F Super Hornet Block III. Sensor fusion reduces the pilots workload significantly allowing him/her to look at a single display instead of multiple displays.
Survivability
4th generation fighter have successfully employed a combination of tactics and systems to ensure survivability against IADs in A2/AD environments. This includes the use of ECM and stand off weapons. ECM systems such as the AN/ALQ-99 used on the EA-18G Growler and Pratorian DASS used on the EF2000 disrupt enemy air defense radars making it more difficult for them to acquire friendly aircraft. These systems also delay detection allowing 4th generation aircraft to get close enough to air defense systems to engage them effectively. Standoff weapons such as the Raytheon AGM-154 JSOW and MBDA Storm Shadow allow aircraft to engage targets well out of the range of air defense systems. The AGM-154 has a range of 70 nautical miles allowing it to be fired well out of the range of most air defense systems such as the Tor, Buk and Pantsir. While engaging targets defended by the S300PMU system the Lockheed Martin AGM-157 JASSM can engage targets at 230 miles away. The combination of ECM jammers and stand off weapons allow 4th generation fighters to engage targets in A2/AD environments.
(EA-18Gs often fly alongside strike packages to jam enemy radars)
Design Flexibility
4th Generation platforms benefit from designs that are not limited to be low observable or have internal bay doors. Almost all 4th generation fighters have a design g load factor of between 7 and 9 as well as a thrust to weight ratio of above 1.0 with certain fuel and armament configurations. This allows aircraft such as the F-16 series or Eurofighter Typhoon maneuverable. The designs also allow for longer ranges due to external and conformal fuel tanks. Aircraft such as the F-15E and F-16V Block 70 can fly at long ranges without the need to refuel prior to engaging.
Combat Proven Success
(The IDFs F-15I has been used extensively over Syria delivering standoff munitions against targets in heavily defended areas)
The recent use of 4th generation fighters in contested environments proved the success of employing stand off weapons into denied air space. Syria in 2018 saw to major engagements that evolved 4th generation aircraft engaging heavily defended targets. The first example saw F-15Is deploy standoff Popeye air to surface missiles against targets in Syria. The same tactic was used by Dassault Rafale, Eurofighter Typhoon and Boeing B-1Bs to engage Syrian chemical weapon sites.
