Here's What You Need to Know: Stealth aircraft are not truly ‘invisible’ to detection.
At 8 p.m. on March 27, 1999, a bizarre-looking black painted airplane cut through the night sky over Serbia. This particular F-117 Nighthawk—a subsonic attack plane that was the world’s first operational stealth aircraft—flew by the call sign of Vega-31 and was named “Something Wicked.” Moments earlier, it had released its two Paveway laser-guided bombs on targets near the Yugoslav capital of Belgrade. Its pilot, Lt. Col. Dale Zelko, was a veteran with experience in the 1991 Gulf War.
A dozen Nighthawks had deployed to Aviano, Italy on February 21 to participate in Operation Allied Force—a NATO bombing campaign intended to pressure Belgrade into withdrawing its troops from the province of Kosovo after President Slobodan Milosevic initiated a brutal ethnic cleansing campaign seeking to expel the Kosovar Albanian population.
The Yugoslav National Army (JNA) possessed a mix S-75 and S-125 surface-to-air missile systems dating back to the 1950s and 1960s, as well as more recent 2K12 Kub mobile SAMs and MiG-29 Fulcrum twin-engine fighters. Together these posed a moderate threat to NATO warplanes, forcing them to fly at higher altitudes and be escorted by radar-jamming planes like the EA-6B Prowler.
However, that evening the Prowlers were grounded by bad weather. Something Wicked and her three flight mates were dispatched anyway because their faceted surfaces drastically reduced the range at which they could be detected by radar and shot at.
Suddenly, Zelko spotted two bright dots blasting upwards through the clouds below, closing on him at three-and-a-half times the speed of sound. These were radar-guided V-601M missiles, fired from the quadruple launch rails of an S-125M Neva surface-to-air missile system. Boosted by a two-stage solid-fuel rocket motors, one of the six-meter long missiles zipped so close that it shook Vega 31 planes with its passage. The other detonated its 154-pound proximity-fused warhead, catching Zelko’s jet in the blast that sprayed 4,500 metal fragments in the air.
Something Wicked lost control and plunged towards the ground inverted. The resulting g-force was so powerful Zelko only barely managed to grasp the ejection ring and escape the doomed Nighthawk.
How had a dated Serbian missile system shot down a sophisticated (though no longer state-of-the-art) stealth fighter?
Zelko’s adversary that evening was Serbian Col. Zoltán Dani, commander of the 250th Air Defense Missile Brigade. Dani was by all accounts a highly motivated commander who studied earlier Western air-defense suppression tactics. He redeployed his Neva batteries frequently, in contrast to the static posture adopted by ill-fated Iraqi and Syrian missile defenses in the Middle East. He permitted his crews to activating their active targeting radars for no longer than twenty seconds, after which they were required to redeploy, even if they had not opened fire.
The S-125M wasn’t normally considered a ‘mobile’ SAM system, but Zoltan had his unit drilled to redeploy the weapons in just 90 minutes (the standard time required is 150 minutes), a procedure facilitated by halving the number of launchers in his battery. While his batteries shuttled from one site to another, Dani also setup dummy SAM sites and decoy targeting radars taken from old MiG fighters to divert NATO anti-radiation missiles.
Thanks to the decoys and constant movement, Zoltan’s unit didn’t lose a single SAM battery despite the twenty-three HARM missiles shot at him by NATO war planes.
Dani had noticed that his battery’s P-18 “Spoon Rest-D” long-range surveillance radar was able to provide a rough track of Nighthawks within a 15-mile range when tuned down to the lowest possible bandwidth—so low, in fact, that NATO radar-warning receivers were not calibrated to detect it. (Dani initially claimed he had modified the P-18’s hardware to achieve this, but later admitted this was a hoax.)
However, low-bandwidth radars are imprecise and cannot provide a ‘weapons-grade’ lock. However, that the NATO mission planners had complacently scheduled the stealth bombers on predictable, routine flight patterns. Worse, the Serbs had managed to break into NATO communications and could overhear conversations between U.S. fighters and the airborne radar planes directing them, allowing Dani to piece together a accurate picture of those routines.
The missile commander decided to set an ambush for the stealth jets, deploying S-125M batteries with a good firing angle on the NATO jets as they flew back to Italy. The thing is, stealth jets can be detected by high-band targeting radars at short distances. However, that still requires sweeping the sky for targets, and in the process illuminating themselves to enemy radars. That not only gave adversaries a chance to direct stealth aircraft away from the threat, but invited a potential strike by a HARM anti-radiation missile.
Therefore, Dani kept the battery’s targeting radar inactive, but cued them towards the approximate position of the stealth aircraft reported by the P-18 radar. Obligingly, the battery’s P-18 radar detected Something Wicked and three other F-117s—but when the high-band targeting radar activated for a twenty second ‘burst,’ it couldn’t acquire a target.
Dani claims that he had been alerted by spies in Italy that the Prowlers were grounded for that day, so he was willing to take greater risks and reactivated the targeting radar a second time rather than immediately relocating—still without result.
Finally, on the third try an S-125M battery locked onto Something Wicked when it was just eight miles away. Dani claims the window of opportunity came when the F-117 opened its bomb-bay doors to release weapons, causing its radar cross-section to briefly bloom.
After bailing out, Zelko concealed himself an irrigation ditch and only narrowly escaped capture by Serbian search parties that combed within a hundred meters of his position. The following evening, he was whisked to safety by an Air Force combat search and rescue team deployed from an MH-60G Pave Hawk special operations helicopter.
Dani’s unit later claimed the only other Yugoslav aircraft kill of the war, shooting down a U.S. F-16 on May 2. Another F-117 was damaged by a missile on April 30 but managed to return to base.
Something Wicked impacted Yugoslav soil upside down near the village of Budanovci. Parts of the wreckage can be seen today at the Serbian Museum of Aviation in Belgrade. Components were also flown to Russia and China and studied to inform their own stealth aircraft programs. Dani kept the plane’s titanium engine outlet as a memento.
The F-117 shootdown was an embarrassing, though fortunately non-fatal, episode for the U.S. Air Force. It has been endlessly cited since as ‘proof’ that supposedly radar-invisible stealth planes could ‘easily’ be shot down by even dated Soviet-era SAM systems.
The truth is more complicated. Zoltan’s ploy of using low-bandwidth radars to track stealth aircraft from afar indeed remains a cornerstone of counter-stealth tactics today. (Another is using infrared sensors, though these remain limited to around thirty to sixty miles in range.)
However, getting a platform with a high-bandwidth radar or heat-seeking weapons close enough to actually shoot at a stealth plane remains a major challenge. Afterall, the stealth jet could detect and simply avoid or shoot at an approaching threat. Dany benefited from having good intelligence of the F-117’s flight path that allowed him to position a missile battery very close to Vega-31’s avenue of approach.
Furthermore, the Nighthawk was a 1970s-era design with a larger radar cross-section than the F-22 and F-35. These modern stealth jets furthermore come equipped with their own onboard radars and carry a greater diversity of weapons, making them more dealing with surface- and air-based threats.
The takeaway, ultimately, is that stealth aircraft are not truly ‘invisible’ to detection, and that sufficiently cunning adversary may find ways to ambush or corner them. However, while Col. Dani’s leadership did exemplify many best practices of air defense warfare, his ambush of Vega-31 does not offer a ‘cookie-cutter’ solution to combating stealth aircraft, particularly as both low-observable airplanes and the SAM systems and fighters hunting them improve in capability.
Zelko and Dani would later meet under friendlier circumstances in 2011. The Serbian missile commander had resumed his profession as a baker in his hometown of Skorenovac. The former adversaries recorded a documentary about their meeting and subsequent friendship. For all the considerable ingenuity it invests in high-tech warfare, humankind fortunately also has a remarkable capacity for reconciliation under the most unlikely circumstance.
Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.
This article first appeared in 2018.
Image: Flickr / U.S. Depertment of Defense