Upon seeing this comparison, American weapon enthusiasts reacted strongly, insisting that the Vikings’ 4.5-generation fighter jets cannot compete with the high-tech 5th-generation fighters. The state-of-the-art Eagle ranks just behind the F-22 Raptor. So what does the Gripen E/F bring to the fight?
Certainly, the design philosophies between cost-effectiveness and agility versus stealth technology and data dominance are fundamentally different. Although they seem like fighters from different generations, if one keeps an open mind beyond just the high-tech interior (which the Gripen E/F is by no means lacking), the formidable rival to the F-35 turns out to be the seemingly ordinary Saab JAS-39 Gripen E. How did that happen?
The two fighters have completely contrasting personalities—like a duel between a large, tech-packed SUV and a lightweight, highly agile sports car. They seem unlikely to meet since they’re from the same side, but they have clashed in project bids and data comparisons for air force purchases worldwide—in the Netherlands, Switzerland, Nordic countries, Canada, and fiercely in the Czech Republic. For Thailand, senior air force officials once ardently desired the F-35 but were fortunate that the U.S. refused to sell it. This refusal was certainly due to political reasons and Thailand’s independent stance, unlike South Korea or Japan, which remain under the influence of a military superpower that unjustly bullies others.
Within Thailand’s defense and military equipment circles, there was once a strong push to acquire the 5th-generation F-35 Lightning II. Many senior Royal Thai Air Force officers expressed a deep desire to obtain it, as if lacking this fighter would immediately cost Thailand its airspace sovereignty.
Looking back today, many question whether the U.S. government's refusal to sell was actually a fortunate outcome amid some people’s disappointment. The reasons behind the Eagle’s rejection were not just technical readiness or hangar availability but matters of international power and politics. The U.S. tends to favor obedient, fully compliant partners. Thailand’s independent position—refusing to bow to commands or become a frontline state under a militarily superior power—meant Thailand failed to meet U.S. criteria, no longer being the 'good kid' as in some past eras.
Thailand did not behave like South Korea or Japan, which sacrificed part of their sovereignty to allow U.S. military bases in exchange for limited technology transfer and protective ties that come with restrictions. Not acquiring the F-35 then was not merely about saving a huge budget but about preserving national dignity and an independent stance, not having to play the game of a dominant power that arbitrarily reshapes the world order.
The F-35 offers several game-changing features compared to earlier fighters, starting with Advanced Sensor Fusion. Lockheed Martin proudly touts its 'Active Sensor Management' system—a capability allowing the aircraft to autonomously control, command, and assign tasks to its sensors rather than passively collecting data. This proactive sensor coordination creates the most accurate and reliable tactical picture. The question is, can the Gripen E do this?
The mission to detect, track, and identify real targets in complex battlefields—using data from numerous and diverse sensors—is one of the greatest challenges for modern fighter platforms. Full situational awareness requires comprehensive data fusion, which is a matter of life and death for pilots.
Saab, the venerable Swedish aircraft manufacturer, has been deeply involved with complex data fusion technology across much of its operations for at least 50 years, possibly longer. This is one of Saab’s core competencies. Integrating sensor fusion into command and control networks is essential—not just for a single aircraft but across networks, including other aircraft, early warning radars, and other sensors. The origins of sensor fusion development date back to Sweden’s Draken fighter era.
In fact, Saab pioneered this field starting in the 1980s with experimental integration of high-rate datalinks across platforms. This long experience prioritizes mission success and pilot support. In the Gripen E’s cockpit, pilots are aided by a new task-based command structure. Sensors automatically adjust orientation and parameters to optimize performance. This automation resembles the F-35’s operation—eliminating manual switch toggling or complex procedures for pilots. Saab has advanced this automation further by incorporating artificial intelligence and machine learning to predict mission outcomes and provide advanced decision support, helping pilots choose correct actions at the right moments—such as weapon employment strategies that maximize survival chances or heightened situational awareness for risky scenarios.
The core of the transition from older to modern fighters in Gripen E is that radars and Infrared Search and Track (IRST) sensors are not treated as separate units but work automatically in coordination. When pilots adjust tactical display ranges, it’s not just zooming but the Resource Manager automatically configures the AESA radar’s scan mode, power, and frequency to best suit the focused range. If the radar detects a target, the IRST sensor immediately turns to confirm without the pilot needing to slave sensors manually as in older systems. Track management merges data from radar, IRST, and datalinked aircraft into a single target on the display, avoiding duplicate targets. Gripen’s electronic warfare systems are not just defensive but also sensors integrated with radar to locate enemies. Although automated, Gripen’s philosophy keeps the pilot in control of the engagement.
Today, electronic warfare (EW) is among the top priorities for modern fighters. The Gripen E is upgraded as a primary sensor for offensive operations. EW acts like ears that listen to and intercept enemy radio or radar signals. The Gripen E can identify the source aircraft type, direction, and activity (searching or locking). Instead of only long-range anti-air weapons, the system can jam enemy radars to blind them or create decoys to confuse foes. Electronic protection (EP) defends friendly communications and radars from enemy jamming, maintaining clear battlefield awareness. Gripen E’s EW tightly integrates with AESA radar and IRST, transmitting information from 'ears' (EW) to 'eyes' (radar) for faster target acquisition.
The design philosophies of the Saab JAS-39 Gripen E/F and Lockheed Martin F-35 Lightning II clearly contrast stealth technology against an agility-focused approach. In modern aerial combat, the F-35 and Gripen represent fundamentally different concepts. Naturally, the more expensive option offers superior performance, but suitability for long-term use is another matter. The F-35 embodies 5th-generation platforms emphasizing stealth and networked data fusion, designed to penetrate dense air defense zones. Meanwhile, the Gripen is a 4+ generation multirole fighter prioritizing high agility, self-defense flexibility, and long-term cost-effectiveness.
Stealth versus jamming
The F-35 employs stealth shaping and radar-absorbent materials to "remain unseen," whereas the Gripen relies on its small size and advanced electronic warfare capabilities to survive in combat.
Speed and maneuverability
The Gripen E/F, designed by Sweden’s historic aerospace firm, achieves a top speed of Mach 2.0 (2,205 km/h) and superior close-range agility. The F-35 is limited to about Mach 1.6 (1,930 km/h) to preserve its stealth coating from heat degradation caused by sustained supersonic flight.
Data and weapons management
The F-35’s advanced sensors include the AN/APG-81 radar and a 360-degree Distributed Aperture System (DAS), providing all-around situational awareness akin to sci-fi visuals. The Gripen E uses the Raven ES-05 radar, notable for its exceptionally wide field of view.
Different strengths
Although the F-35 carries more internal fuel and weapons (combat radius about 1,100 km), the Gripen excels in specialized armaments, effectively deploying anti-ship missiles like the RBS15 and cruise missiles such as the TAURUS.
Design philosophy and key features
The JAS-39 Gripen was developed under an Extreme Versatility concept to handle numerically inferior wars. It is a 4th-generation fighter focusing on easy maintenance, requiring few technicians, and capable of operating from highway strips. The aircraft is small, aerodynamically efficient, and highly agile, featuring delta wings and canards.
The American F-35 Lightning II, popular among U.S. allies, is designed for Network-Centric Warfare as an information hub. Its stealth technology reduces radar detectability, while sensor fusion processes data from surrounding sensors to relay real-time intelligence to allied forces. The F-35 prioritizes situational awareness and long-range strike over close-range dogfighting, sometimes allowing pilots to release weapons and return to base without engaging further.
Stealth and detection technologies
The F-35 holds an advantage over the JAS-39 E/F in stealth due to its shape and radar-absorbent materials (RAM), resulting in a very low radar cross-section (RCS). However, some radar types can still detect it. Additionally, it features an Electro-Optical Targeting System (EOTS) under the nose, integrating infrared and laser detection without external pods.
The Gripen E/F is not a stealth aircraft but benefits from naturally low RCS due to its small size. Saab compensates with advanced electronic warfare (EW). The E model uses the Raven ES-05 AESA radar mounted on a swashplate base, allowing a wider scanning angle than typical AESA radars on other fighters.
Flight performance
In terms of speed, the Gripen can reach about Mach 2 and is capable of supercruise—sustained supersonic flight without afterburners—which the F-35 can only do to a limited extent. The F-35 emphasizes a cruising speed of Mach 1.6.
Flight range
The F-35 carries large internal fuel tanks, enabling long-range flights without external tanks that would compromise stealth. The Gripen, while fuel-efficient, has a shorter range due to its smaller size unless air refueling is available.
Weapons and payload
The F-35 stores weapons internally to maintain stealth but has limitations on internal payload capacity. To carry heavier loads, external hardpoints can be used in "Beast Mode," sacrificing stealth characteristics.
The Gripen operates on an open system supporting weapons from various countries, including Europe’s Meteor missile, the U.S.’s AIM-120, and IRIS-T. The E version has up to 10 hardpoints, significantly increasing its payload capacity over earlier models.
Costs and maintenance
Here, the Gripen wins. Its cost per flight hour is several times lower than the F-35—about $4,000–8,000 (roughly 129,400–258,800 baht) compared to over $30,000 (about 970,680 baht) for the F-35. The F-35’s maintenance is more complex, especially for preserving its stealth coating, and requires a logistics system continuously linked to the U.S.
If the goal is a spearhead aircraft to penetrate air defenses and dominate airspace with the world’s most advanced technology, the F-35 is the answer. But for a versatile, easy-to-maintain fighter with a low budget footprint and operational flexibility in full-scale warfare, the JAS-39 Gripen holds a strategic long-term advantage.