defense

How the Serbs Shot Down the US Stealth F-117A Nighthawk in the 1999 Kosovo War

In the Gulf War, more than 1,500 flight sorties were performed without a single F-117 loss. By the end of the war, the F-117 had become a legendary aircraft. When the Kosovo War ended in 1999, the situation was different.

How did the stealthy F-117 Nighthawk come into existence?

The F-117A was the first low-visibility aircraft designed by the US for bomber missions. It was almost famous as the 'Invisible Aircraft'. The F-117 was one of the most innovative aircraft developed up to that time and was the culmination of decades of research into stealth technology. This aircraft, which was claimed to be almost impossible to be seen by radars in the 1990s, was designed as America's 'silver bullet' against the Soviet Union. The primary mission of this bomber was to penetrate deep into enemy territory and destroy the most heavily defended targets. Although it made its first flight in 1981, it was unknown to the American public and even to many in Washington until 1988. Even today, many still prefer to refer to it as a "stealth fighter", despite its lack of air-to-air capabilities and its primary role as a bomber.

The F-117 was the product of first-generation stealth technology, based on a sharp, angular shape made of flat surfaces to reflect radar waves away from itself and at different angles. The aircraft utilised non-circular nozzle tubes that mixed hot nozzle (exhaust) air with cold ambient air, resulting in a very low infrared signature. Since the aircraft used a turbofan engine instead of a turbojet, it was not really a fighter jet. Therefore, it left a low acoustic signature as it did not have afterburners that produced high noise. It also had a low visual signature as it was painted in dark colours and flew mostly at night.

How was the Operational Performance of F-117s?

The F-117 was first used in Panama in 1989 as part of "Operation Just Cause" to surprise and paralyse General Noriega's forces. In 1991, it performed remarkably well in Operation Desert Storm. Although it flew 3% of the total flight sorties in this war, almost 30% of the targets hit were disabled by this aircraft. In particular, it managed to bomb Baghdad city centre, which was considered one of the best defended cities in the world at the time, several times without any casualties. F-117s were always planned for high-risk missions in a high-intensity war environment. Despite this, more than 1,500 flight sorties were performed throughout the war without a single F-117 loss. By the end of the war, the F-117 had become a legendary aircraft.

Undoubtedly, a common saying in military aviation was also valid for this aircraft: "The enemy always has a trick, an unknown face!" This means: No matter how good your intelligence is, no matter how intelligent and well-trained you are as a pilot, no matter how weak the enemy appears, you can always face something you did not expect in combat conditions. The enemy may overthrow you with a method or technique developed at that moment, which you did not foresee. You may be caught unprepared. It can hit you where you do not expect it.

How could the Serbs shoot down the F-117 aircraft?

The situation faced by Pilot Colonel Dale Zelko, whose F-117 aircraft was shot down during the Kosovo War, is a good example of the situation mentioned.

In 1999, on the fourth night of the war, Colonel Zelko took off in his F-117 Nighthawk for a night flight. Opposing him was Zoltan Dani, the Serbian commander of the land-based SA-3 surface-to-air missile battery. Designed in the 1950s, the short-range SA-3 was essentially obsolete by the time of the Kosovo War. Many armies had either retired it or given it to third world countries. In the hands of Zoltan, a battery commander with a high level of experience and training, this old defence system was transformed into a new weapon.

Before the war, Zoltan was an officer who had witnessed how Israel destroyed 29 of Syria's 30 surface-to-air missile sites in less than two hours during the 1982 Lebanon War. This experience made him realise that the only advantage a ground-based defence system could use against an attacking enemy aircraft was mobility, and that mobility was the key to survival. Although the SA-3 was designed as a fixed system that could not be moved, he realised that a group of trained soldiers could disassemble the SA-3 system in less than 90 minutes and load it onto lorries, which the system allowed. He therefore chose to move several times a day to relocate the SA-3 battery he commanded. Each relocation naturally made it more difficult for NATO intelligence agencies to locate the battery.

However, the main threat to the SA-3 battery was the HARM anti-radiation missiles carried by SEAD (Suppression of Enemy Air Defences) aircraft operating in conjunction with the bomber columns. When the SA-3 system switched on its radar, it realised that these aircraft, which were hovering in the air, were launching HARM missiles to hit the SA-3 battery. However, as soon as he switched off the system's radar, he realised that the HARM missiles were 'blinded' as they headed towards the radiation source, so he was able to deflect the HARM missiles. This led him to develop a strict rule of not using the SA-3 radar in a single location for more than 40 seconds. He further increased the survivability of the SA-3 system by constructing homemade dummy targets from the radars of previously confiscated Iraqi Mig-21 aircraft. These dummy targets were placed far enough away from the SA-3 emplacement so that when the SA-3 was switched off when a HARM missile was fired, the missiles would be directed at the dummy target and be wasted.

How did the SA-3 shoot down the F-117?

When fate brought F-117 pilot Zelko and SA-3 Commander Zoltan together, night conditions prevailed and the weather was very bad. Therefore, the bombing missions of all NATO aircraft, except for 8 F-117s operating in the region, were cancelled. Meanwhile, Zoltan was receiving intelligence that F-117s were taking off. The Yugoslavian army had spies stationed around NATO bases, which made it easy to access information about NATO aircraft taking off. Zoltan, who always kept track of which aircraft took off from where, was able to predict the type of aircraft a possible strike package would consist of. He could also calculate, with little error, how long the planes would stay in the air.

As Colonel Zelko approached his target, Zoltan ordered the SA-3 controller to switch the radar on for 20 seconds and then switch it off. However, he failed to detect any of the F-117s he thought were approaching to attack the SA-3 battery he commanded. Nevertheless, he ordered the radar to remain on for another 20 seconds, knowing that one F-117 would make its attack within a minute and then move out of the effective range of the SA-3. As the seconds ticked by, he and his men desperately tried to find the almost invisible aircraft. By the time the 60-second deadline had almost dawned, his men were thoroughly demoralised and knew they had to begin the process of relocating the SA-3 without delay. This time Zoltan instead ordered the SA-3 radar to be switched on for the third time, contrary to his earlier instructions. This was because Zoltan considered that there were no SEAD aircraft in the F-117 package arm, that these aircraft had not taken off due to bad weather, and that there was therefore no danger of a HARM missile attack on the SA-3 position.

So at 20:15 Zoltan's men spotted Colonel Zelko dropping his bombs on the target. The hatches of Colonel Zelko's weapons bay were opened and the F-117 was now visible on radar. It was no different from any other aircraft. There was a window of opportunity to shoot down F-117s that were visible on radar, even if only for a few seconds. Zoltan immediately ordered his team to target the F-117 and launch two missiles. By this time the F-117 had completed its mission and closed its gun release doors. However, the SA-3 had not yet broken the lock. The radar had maintained its lock.

Shortly afterwards, the F-117 pilot, Colonel Zelko, realised that missiles were being fired at him. However, the missiles were travelling at three times the speed of sound, so he assessed that there was not much time to take evasive manoeuvres. He felt the first missile pass directly over his aircraft. In fact, it passed so close that the aeroplane seemed to shake a little. Then, when he opened his eyes wide and turned his head in the direction from which the missiles were coming, he realised that another missile was coming towards him. The collision between the missile and the aeroplane was very violent. Zelko would remember seeing minus seven G's at this time. His body was pulled up off the seat and into the canopy. As he struggled to reach the ejection levers, a single thought ran through his mind: "This is really, really, really, really bad."

Zelko, who barely managed to jump, was rescued by the combat search and rescue teams in the area and began flying again a few weeks after this accident. Meanwhile, the innovative tactics of Zoltan, the commander of the SA-3 battery, and the success of his mission with his team in shooting down the F-117, had dealt a major blow to NATO forces, especially in terms of morale. Underestimating the Yugoslav air defences had led to a number of errors in the operational planning process. Zoltan was able to capitalise on these mistakes and shoot down an F-117.

Conclusion

The F-117 was a revolutionary light bomber that first demonstrated the potential and importance of stealth technology. It was the first operational aircraft to use stealth technology to evade enemy radar and penetrate heavily defended airspace. The role of the F-117 was to drop precision-guided bombs unseen on the target. It proved its effectiveness in many operations. Nevertheless, it was retired in 2008 after 25 years of service and replaced by the more advanced and versatile low-visibility fifth generation stealth aircraft.

As seen in the Kosovo war, the F-117, which was designed in the 1970s and entered service in 1983, proved to be less effective against air defence systems in the 2000s. The F-117 used angular fuselage surfaces and special coatings to reduce the radar cross section (RCS). However, these were not invisible to radar, especially low-frequency radar, which could detect the aircraft's general position.

In fact, the F-117 was an expensive and difficult aircraft to maintain, because it had to be stored in climate-controlled hangars and its special coatings had to be checked regularly and repaired when necessary to maintain its stealth capability. The F-117 was also covered with toxic chemicals that posed a health risk to the personnel involved in its maintenance.

Although the F-117 Nighthawk was shot down by the Serbs with SA-3 fire in 1999 during the Kosovo Operation, I believe that the F-117 Nighthawk aircraft, which also played an inspirational role for fighter aircraft such as the F-22, F-35, MMU Kaan, has found itself a glorious place in the history of military aviation as the first aircraft that comes to mind when invisibility is mentioned.

After all, the SA-3 system is not an antique or anachronistic toy for aircraft from the 1960s. It has a proven track record of shooting down aircraft used by skilled aviators. The fact that it has been extensively developed is a testament to its versatility and adaptability. It is also a testament to its prowess as a surface-to-air missile defence system. Nevertheless, the question can be rightly asked: If the Nighthawks were able to fly over the beehive in Baghdad in the First Gulf War without incident, why did a single Serbian missile battery shoot down a supposedly "invisible" aircraft.

SA-3 Missile Defence System

The S-125 Neva/Pechora is a Soviet-made surface-to-air missile. It is typically launched from the bed of a PR-14 carrier truck with a hydraulically operated mechanism to raise and lower the missile apparatus. Neva was the internal name of Soviet military forces. Pechora was the name given for export [source]. It is also known by its NATO reporting name, SA-3 Goa. The Soviet Navy operated a naval version known as the M-1 Volna. The S-125 was first deployed in the Soviet army in 1961, primarily as an urban defence battery.

The missile was a dual-stage design, fuelled by solid rocket propellant motors capable of accelerating the weapon to speeds in excess of Mach 3. With a range of 15 km and a maximum altitude of 10 km, the S-125 was a formidable air defence system when it was first designed and built.

The S-125 system can utilise two different types of missiles, the V-600P and V-601P, which differ in several ways.

V-600P: This variant is about 5.8 metres long and has a high-explosive fragmentation warhead. The 60 kg warhead, which triggers the dispersal of 3,500 metallic fragments, each with a radius of about 12-13 metres, works with both a radar proximity fuse and an impact fuse. This variant has a range of 15 km and a maximum altitude of 10 km and detects targets by radio command guidance.

V-601P: This variant is slightly larger at around 6 metres and provides an extended maximum range of 18 km and a maximum altitude of 14 km. The main difference in the V-601P is the improved 72 kg warhead, which carries 4,500 pieces of metallic fragments dispersed in a similar blast radius.

A third, more modern variant is also available, introduced in the 1980s and continuously upgraded since then:

V-601D (5V27D): The 5V27D is even larger than the V-601P and is compatible with the 9Sh33A Karat 2 scope for daytime optical angle tracking.

Tracking Systems and Fire Control Radar

The missile system typically uses an SNR-125 Low Pulse radar system for fire control, target detection and tracking. The SNR-125 is specifically designed for use with the S-125 system. It is equipped with two separate fixed scanning antennas and also consists of the following components [source]:

A UV-10 Radar

A pair of orthogonal UV-11 Receivers acting as 'height finders'

A single UV-12 missile uplink radar

Despite the ability of the missile system to be transported by road with mobile units. The installation time required to make the system fully operational is very large. In fact, the excessive time required to install the missile launchers and radar led to the development and deployment of the SA-6 Gainful missile system in 1967.

Effectiveness of SA-3 Goa

SA-3 Goa bears a more specific level of scrutiny in the context of the 1999 downing of the F-117. Many magazines, articles, online forums and countless comment sections often claim that modern stealth fighter aircraft are shot down by "antiquated" or obsolete technology. There may be a small grain of truth in these claims. But as always, the reality of the events of 1999 is a little more nuanced and complex than popular portrayals suggest.

Let us examine the service history of SA-3:

The SA-3 Goa was first put into combat during the 1967 War of Attrition. Soviet military personnel were placed alongside the Egyptian SAM crews. This crew successfully shot down several F-4E Phantoms and one A-4 Skyhawk aircraft.

US-made ALQ-101 Jamming Pods were unable to intercept these strikes. This was a result of the SA-3's alternate antenna scanning frequencies.

Reports indicate that the SA-3 Goa outperformed other missile defence systems during the 1975 Yom Kippur War.

The system was widely used in the Iran-Iraq War with an unknown degree of effectiveness.

Although Israel captured an SNR-125 and shared technical details with the United States. To create special mitigating countermeasures. Iraqi SAM batteries managed to shoot down several Coalition aircraft using this system.

Poland has delivered an advanced version of the S-125 to Ukraine, and Ukraine may have used this system to shoot down a Su-35.