Key Points and Summary – On June 29, 1987, a U.S. Air Force SR-71 Blackbird suffered a catastrophic engine failure during a reconnaissance flight over the Baltic Sea, making it vulnerable to interception by Soviet fighters. As nearly 20 Soviet MiGs scrambled to intercept the crippled American spy plane, four Swedish Saab 37 Viggen pilots made a critical decision.
-Recognizing the SR-71’s distress, the Swedish pilots intercepted the Blackbird and formed a protective escort, shielding it from potential attack and safely guiding it back toward friendly territory. The heroic act remained classified for over 30 years.
Meet the Saab 37 Viggen
The Saab 37 Viggen is the predecessor of the commercially successful JAS 39 Gripen. Its service throughout the Cold War was primarily used only to protect neutral Sweden’s borders from Soviet or American aircraft.
However, in one such situation, several Grippens played a critical role in one of many close calls between the Soviets and the Americans. Classified until the late 2010s, many readers are likely still unaware of the one time a Swedish aircraft was able to intercept the venerable SR-71 Blackbird.
The Blackbird Suffers an Accident Near the USSR
One of the most dramatic moments of the Viggen’s history occurred during the later years of the Cold War, when a JA 37 had a run-in with the famous Blackbird. On June 29, 1987, during a routine reconnaissance flight by a U.S. Air Force SR-71 Blackbird over the Baltic Sea. The SR-71 was flying at around 75,000 feet when it suffered a catastrophic failure in its right engine.
The crew, Lieutenant Colonel Duane Noll and Lieutenant Colonel Tom Veltri, were forced to descend rapidly to 25,000 feet, drastically reducing their speed and making the aircraft vulnerable to interception.
Unfortunately, this did not go unnoticed by the USSR. Soviet radar operators detected the anomaly and reportedly scrambled up to 20 fighters, including MiG-25s, to intercept the American aircraft. The SR-71, now flying at a much lower altitude and speed, was within reach of Soviet interceptors. If captured or shot down, the incident could have escalated into a serious diplomatic crisis. Additionally, had the Soviets captured the Blackbird, it would have revealed all the trade secrets involved in the SR-71’s design and bolstered the Soviets’ aerospace industry.
How Swedish Jets Were Able to Intercept the SR-71
Fortunately, Sweden’s air defense system had long been monitoring the SR-71’s flights, which they referred to as the “Baltic Express.” Although the Viggen could not normally intercept the Blackbird at its cruising altitude, Swedish pilots had trained extensively to respond to emergencies. On that day, two Viggens were already airborne on a training mission, and two more were scrambled from Quick Reaction Alert stations. The four pilots (Colonel Lars-Erik Blad, Major Roger Möller, Major Krister Sjöberg, and Lieutenant Bo Ignell) intercepted the SR-71 as it entered Swedish airspace.
Recognizing the aircraft’s distress, the Viggen pilots made a critical decision. Rather than treating the SR-71 as a potential intruder, they chose to escort it out of danger. Flying in formation with the crippled Blackbird, the Viggens provided a protective screen against any Soviet fighters that might attempt to intercept.
Their presence served as a clear signal: Sweden would not allow the aircraft to be attacked while in its monitored airspace. The SR-71 was safely guided back toward NATO-controlled territory, and the incident ended without confrontation.
Classified Until Recently
This act went unnoticed by the world for decades as the event remained classified until the 2010s. Sweden, officially neutral during the Cold War, had to maintain a delicate balance between East and West. Publicizing the rescue could have jeopardized its diplomatic standing. It wasn’t until 2018 that the story was officially acknowledged.
In a ceremony held in Stockholm, U.S. Air Force Major General John Williams awarded the Air Medal to each of the four Swedish pilots. The recognition was not only for their flying skills but also for their courage and judgment in a moment that could have had far-reaching consequences.
With this event, the Saab 37 Viggen became the only fighter jet to ever lock onto the SR-71. The scrambled Viggens made several successful interceptions of the spy plane and ultimately protected it from Soviet interceptors.
This event highlighted the impressive capabilities of the Viggen, which was able to keep up with the famous Blackbird (granted it was only flying on one engine).
What Made the Saab 37 So Successful?
The Viggen was conceived in the 1960s as part of Sweden’s “System 37” initiative, which aimed to create a family of aircraft capable of fulfilling multiple roles. The result was a versatile platform that came in several variants, including the AJ 37 for ground attack, the SF 37 for reconnaissance, the SH 37 for maritime surveillance, and the SK 37 for training.
The most advanced version, the JA 37, was developed as an interceptor and entered service in the late 1970s. It featured a powerful Volvo RM8B engine, derived from the Pratt & Whitney JT8D, which allowed it to reach speeds exceeding Mach 2.1. The aircraft’s delta wing and canard configuration gave it excellent maneuverability and short takeoff and landing capabilities, essential for operating from Sweden’s network of road bases.
One of the Viggen’s most groundbreaking features was its avionics suite. It was the first fighter aircraft to be equipped with a digital central computer, the CK 37, which integrated navigation, radar, and weapons systems.
This enabled rapid data processing and decision-making, giving Swedish pilots a technological advantage. The aircraft also featured an advanced datalink system that enabled real-time communication and coordination between aircraft and ground stations—a precursor to the network-centric warfare concepts seen in modern air forces.
The Viggen was retired in 2005, replaced by the more modern JAS 39 Gripen. Yet its legacy endures. It remains a symbol of Sweden’s commitment to innovation and independence in defense.
The aircraft’s influence is evident in the Gripen’s design philosophy, which continues to emphasize versatility, advanced technology, and cost-effective operation.
About the Author: Isaac Seitz
Isaac Seitz, a Defense Columnist, graduated from Patrick Henry College’s Strategic Intelligence and National Security program. He has also studied Russian at Middlebury Language Schools and has worked as an intelligence Analyst in the private sector.
Military Affairs
China’s Stealth Air Force Has 1 Mission
China’s J-20 Mighty Dragon Is Built for War
The F-22 Raptor Is Getting a Makeover