This week 30 years ago, a teenager called Mathias Rust evaded fighter jets and the world’s most sophisticated air defence technology to land a light aircraft in the heart of Moscow.

Dr Robin Stott loads up a video on the computer in his study in Greenwich in south-east London. The film has been transferred from an old video camera. The colour is subdued, with the characteristic faded palette of old VHS tapes.

Stott took the footage almost 30 years ago to the day, but a long way from the parks and pubs of Greenwich. It is just after 19:00 on 28 May 1987. It is springtime in Moscow, the biggest city in the Soviet Empire. And it is the height of the Cold War.

It was not easy for a Westerner to visit Moscow, but Stott had friends in high places; his friend, a cardiologist and peace activist, was Soviet leader Mikhail Gorbachev’s personal physician. Stott was taking part in a peace conference calling for nuclear disarmament. The conference was not going well.

“Peace conferences are always fractious affairs,” says Stott. “Everyone’s always fighting about something.”

Stott took the opportunity to “get some fresh air” and grabbed his video camera for a stroll around the Kremlin and Red Square. His footage shows the onion domes of St Basil’s Cathedral in the early evening light. Red Square is mostly empty; there is the occasional snatch of Russian as passing Muscovites talk loud enough to be picked up on camera. Stott apologises for the slow pace. “Nothing is as boring as watching somebody else’s holiday video, is there?” he laughs.

There is a moment when Stott’s camera microphone picks up the buzz of a low-flying aircraft as his camera is trained on the imposing architecture. A few minutes later, a jump cut shows the plane – a single-engined Cessna that is flying low to the ground. Another jump cut, and the Cessna is taxiing on the edge of Red Square itself. Within moments, a crowd of curious onlookers has surrounded the Cessna.

Stott’s film shows the pilot – a curiously calm and assured young man – laughing and smiling with the crowd, one of whom eventually starts questioning him in English.

The pilot is Mathias Rust. He has just flown his Cessna 172 single-handedly across the most heavily defended border in the world, through highly sophisticated air defences. The repercussions, some believe, would ultimately help hasten the end of the Soviet Union itself.

***

Mathias Rust is 18 in 1987. He has two obsessions – flying and politics. Rust has started taking lessons at a local flying club near Hamburg in West Germany, and racked up some 50 hours’ worth of flying time.

Europe is on edge. It is more than 40 years since the Soviet Union and the Western Alliance have effectively split the continent in two. Since then, the massive military forces of Nato and the Warsaw Pact have been ranged against each other across a border that runs from the north of Norway to the far-eastern reaches of Turkey. Every now and then, the Cold War that has frozen relations since the end of World War Two threatens to get much hotter.

The USSR is in a state of flux, exacerbating the effects of late premier Leonard Brezhnev’s economic stagnation

The Cuban Missile Crisis of 1962 is often regarded as the tensest moment of the Cold War. But the early 1980s has also brought the two nuclear-armed superpowers close to military clashes.

In 1983, South Korean Airlines Flight KAL 007  strayed into the USSR’s airspace near Japan and was shot down by a Soviet fighter, killing all 269 of those on board. The US then announced it is planning to base Pershing mid-range nuclear missiles in its bases in Europe. And a few months later, an elaborate Nato military exercise called Able Archer ’83 caused such a spasm of panic amongst Soviet military chiefs that the incident is now regarded as the closest the two sides got to a nuclear war.

 

Watch how Rust's flight unfolded in BBC Future's animated video

US president Ronald Reagan was an avowed enemy of communism. The USSR is in a state of flux, exacerbating the effects of late premier Leonard Brezhnev’s economic stagnation. The 1980s has already seen two Soviet premiers – Yuri Andropov and Konstantin Chernenko – die after briefly ruling the Politburo. Mikhail Gorbachev, the third Soviet premier in less than 18 months, was the youngest to ever hold the post when he is voted in in 1985.  

Despite being the first premier to have been born after the Russian Revolution, Gorbachev was seen as a moderate and a reformer. There was optimism in the West that the 59-year-old Gorbachev may help break the tension that has built up over the past few years.

Reagan and Gorbachev arranged a summit in Iceland in October 1986, an attempt to broker a new deal to reduce each country’s arsenal of intermediate-range nuclear missiles – the kind of weapons most likely to be used in a nuclear exchange in Europe. Held at the former French Consulate at Hofdi near Rejkjavik, the talks collapsed at the last minute.

The failed summit had a big effect on the teenage Rust. West Germany is likely to be the centre of any conflagration. “There was a real sense of fear,” Rust told Smithsonian Air & Space magazine in 2005, “because if there was a conflict, we all knew we would be the first to be hit.”

Rust wants to make a statement. His idea is to build a metaphorical “bridge of peace” between the West and East using an aircraft from his flying club.

He can’t fly over into East Germany, however. It is one of the most heavily policed borders in the world, with a formidable air defence network of fighter planes and missile systems. Rust’s plane is likely to be shot down minutes after he crosses the border.

Rust, instead, hatches a more ambitious plan. He will fly a Cessna 172 – a small, reliable single-engined plane that has been rolling off production lines since the 1950s – from West Germany across the North Sea via the Shetland and then Faroe Islands, and then from there to Iceland. The flight will give him valuable experience in long-range navigation, which he is going to need. Then he will have to fly to Helsinki, and from there – somehow – across the Soviet border. Most of the USSR is off-limit to foreigners, and there will be no guidance from air-traffic control, who will consider him a possible threat. If Rust manages to make it over the Soviet border, he will be on his own.

The Cessna 172 Rust takes for his flight has been modified – two of its four seats have been removed so more fuel can be carried. He takes little with him apart from a sleeping bag, spare engine oil, a life jacket and a crash helmet, in case he faces a bumpy landing in Moscow.

Rust’s course makes it look like he’s heading to Stockholm, but after leaving Helsinki air traffic zone, he heads south

Rust takes off from Uetersen Airfield, near Hamburg, on 13 May, having booked the Cessna for three weeks. He does not tell anyone where he is planning to go. He arrives in Iceland two days later. He spends a week planning his audacious flight. To help pluck up his courage, he visits Hofdi House, the imposing white building where Reagan and Gorbachev met. “It gave me motivation to continue,” he told Smithsonian Air & Space.

Rust then aims for Norway, arriving in Bergen on 22 May. Three days later, he lands in the Finnish capital Helsinki. It is from here he will mount the most dangerous part of his mission.

When he takes off on 28 May, just after noon, Rust tells Helsinki air traffic control that he is heading to the Swedish capital Stockholm; the night before, the teenager had filed a flight plan for it just in case his nerves got the better of him.

Rust’s course makes it look like he’s heading to Stockholm, but after leaving Helsinki's air traffic zone, he heads south. He has deactivated the plane’s transponder – a device that gives a unique reply to radar systems so it is easier to track. Air traffic controllers at Finland’s second city of Tampere warn Rust he appears to be heading off course.

At around 13:00, Rust’s plane disappears off Finnish radar screens. Shortly after, debris is spotted on the water near Rust’s last-known position. Rust’s plane is then spotted by a Soviet military radar post in what is now Latvia.

Western aircraft are forbidden from entering Soviet territory without express permission – and they also have to stay within special corridors. Rust has no permit – he is now classified as an ‘unidentified aircraft’ by Soviet radar.

***

Rust’s plane is now approaching the world’s largest air defence system. The Soviet Union’s border stretches east to west from the Sea of Japan to Poland, and from the Arctic Circles to Iranian frontier. It is 60,000km (37,000 miles) long, and an entire military force is tasked with protecting it. The Soviets call it the PVO (Voyska Protivovozdushnoy Oborny, or Anti-Air Defence Troops). It has three separate branches – one in charge of radar posts, one of missile units, and another flying interceptors – fighter plane designed to stop aerial attack.

When Rust is pointing his humble Cessna toward the USSR, the PVO boasts more than 2,000 interceptors and some 8,000 missile launchers stretching across the USSR. It is an enormous network designed to prevent US bombers from targeting Soviet cities and military installations.

Rust’s flight, it turns out, takes place on the one day a year when the Soviet borders are not guarded quite so vigilantly

The PVO’s fleet includes some extraordinary aircraft; the MiG-25, designed to intercept the US’s Lockheed SR-71 Blackbird and which can fly at nearly three times the speed of sound; and the Tupolev Tu-128, the largest fighter plane ever built, which patrols the frozen wastes of the Soviet Arctic and fires missiles 17ft (5m) long. The PVO’s arsenal also includes hundreds of smaller, swing-wing MiG-23 fighters stationed at air bases near the border.

The PVO is formidable, but it is rigid and designed for a very specific task. US bombers like the Boeing B-52 are the size of airliners, and likely to be flying at high altitude. Their great size means they generate a bigger signal on radar screens. Like most radar systems of the day, the Soviets’ air defence network is very good at picking up these large radar signatures flying at great height, but less effective at picking up small aircraft flying close to the ground.

This is radar’s Achilles heel – when you’re trying to track a small moving target close to the ground, the plane’s ‘echo’ is lost amid the much larger signature bounced back from hills and buildings. It makes a small plane very difficult to detect. The kind of radars carried by Soviet fighters in the 1980s were just as ineffective; the huge signal from the ground below ‘swamped’ that generated by the small plane. MiG pilots had to be directed to the approximate area until they could locate such targets visually.

Rust’s flight, it turns out, takes place on the one day a year when the Soviet borders are not guarded quite so vigilantly – Border Guards Day. It is a national holiday, and many of the border posts are under-staffed (or dealing with hangovers). This adds to the confusion, and a series of assumptions and mishaps that prevent Rust’s plane from being correctly identified.

The Soviets' blunders go from sloppy to farcical. The first MiGs to sight Rust’s plane do so from a distance. They think Rust’s Cessna is a Yak-12, a very similar-looking plane used by Soviet flying clubs and to train novice air force pilots. MiG-23s scrambled to identify the plane finally find Rust’s Cessna – which has been hidden below cloud – and zoom in head on as if to attack him.

“I remember how my heart felt, beating very fast,” Rust told Smithsonian Air & Space. “This was exactly the moment when you start to ask yourself: ‘Is this when they shoot you down?’”

One MiG slows down as if to land – even extending its landing gear – so that the pilot can get a better look. Rust and the MiG pilot stare at each other. The MiG then flies off. The pilot reports that he has just identified Rust’s plane as a West German light aircraft, but senior commanders think he is mistaken.

The enormous fall-out from the KAL 007 incident has made Soviet commanders cautious; to avoid another mishap, pilots are told the order to intercept has to come from the very highest levels. Defence Minister Sergei Sokolov – the man whose permission would have to be given – is in East Germany for a high-level meeting, compounding the confusion.

Other ground controllers assume Rust’s plane is a training aircraft that has failed to update its transponder, and classify it as friendly. Rust again has luck on his side – as he flies closer to Moscow he enters a training range where similar Soviet planes are on practice flights.

Stott’s video shows an oddly relaxed scene; the teenage Rust is calm and assured

Even if missile batteries had been told to shoot down Rust, it would not exactly be easy. Many of the nonetheless formidable Soviet missile batteries are almost useless in such a situation. Missiles like the SA-4 and SA-5 are designed to deal with large, high-flying bombers; and they have a minimum height before they can be directed to a target. A Cessna flying as low as Rust’s would be well below this minimum range; the missiles would just fly straight past.

Rust flies on, using rudimentary maps he’d bought in West Germany to check off landmarks. Eventually, in the early evening, he sights Moscow. The city is much bigger than he expected, and it is some time before he is able to locate the bulbous domes of St Basil’s. He flies lower and lower, scouring the Moscow landmark for a safe place to land.

That Rust is able to land his plane is another of the day’s extraordinary coincidences. He lands the Cessna on the Bolshoy Moskvoretsky Bridge, an eight-lane crossing that was the first modern concrete bridge built in the Soviet capital in the 1930s. This connects Red Square with Zamoskvorechye on the south side of the Moskva River. The bridge is a trolley bus route, and is normally covered with electrical wires; however, one section of these were removed earlier that day for maintenance, giving Rust just enough room to land.

Stott recalls Rust’s landing. “I ambled over to the place where Matthias Rust was getting out of his aircraft,” he says. “Nobody else was there.” Muskovites who had watched in disbelief at Rust’s landing start to surround the aircraft.

Stott’s video shows an oddly relaxed scene; the teenage Rust is calm and assured. The Russians are surprised but friendly. It looks no more serious than a tourist meeting a bunch of interested locals.

“There was a woman who could speak some English who started talking to him… she asked him ‘What are you doing here?’ He intimated that he did it for peace.

“She then asked him what he was going to do now. He said ‘I’m going to take off again.” She laughed and said, ‘Brave boy! Brave boy!’”

“He just seemed to be a cool operator, really,” says Stott. “In a way, he seemed like those old photos of Von Richtofen in World War One, nonchalantly leaning on his plane in a relaxed manner.

It was as if landing his plane in Red Square was the most ordinary thing – Robin Stott

“It was as if landing his plane in Red Square was the most ordinary thing.” Stott continued recording until the KGB arrive. The crowd was quietly dispersed, but no-one asked Stott to stop filming. Soviet guards stood around Rust’s plane talking amongst each other, clearly at a loss as to what to do.

The KGB eventually detain Rust, taking him away to interrogate him. The Cessna was disassembled at a nearby airport – the Soviets could not seemingly believe that a teenager acting on his own could penetrate the Soviet air defences all the way to Moscow.

Stott says that “they thought it was some kind of set-up. He was a peace activist, and I was a peace activist. But I had no idea it was going to happen.”

Stott thought the KGB would come looking for him once they realised he had the footage on film. That night, in his room in the enormous riverside hotel, the Rossiya, Stott got a knock on the door. “It wasn’t the Russians though – it was the Americans. It was some people from NBC, the American channel, and they wanted to buy my footage.” Stott’s home video turned Rust’s flight into a global story.

Rust was tried with illegal entry, violation of flight laws, and “malicious hooliganism” – the latter charge he vehemently denied – and was sentenced to four years in Lefortovo Prison, a high-security jail on 4 September. Rust spent nearly a year in jail and returned to West Germany in 1988 after being pardoned by Gorbachev. But later, his story took a dark and unexpected turn: in 1989, he stabbed a nurse who, a court heard, had refused his advances, leading him to spend a further 15 months in prison.

Today, Rust is an enigmatic figure, and BBC Future could not reach him to request an interview. Recent reports describe him as everything from a financial analyst to a yoga instructor to a peace envoy. It’s believed he makes much of his living as a high-stakes poker player.

He has, reportedly, never flown a plane since.

***

The effect of Rust’s flight for peace widened.

Gorbachev used the incident as a tool to remove hardliners who opposed his sweeping reforms. The confusion that helped Rust fly to Moscow gave him an excuse to sweep some of the old guard out of the way. Defence Minister Sokolov and Alexander Koldunov were among hundreds of commanders who lost their jobs. It was a Stalinist purge, minus the show trials and firing squads.

Gorbachev’s reforms – the openness of glasnost, the economic revolution of perestroika – gathered pace. Within three years the Soviet Union was no more.

The Russians did their best to play it down, which is unsurprising as it was a serious breach of Soviet air defence – Mike Bratby, air defence expert

Rust’s flight showed that even seemingly impregnable air defence systems – with hundreds upon hundreds of fighter planes, and thousands of missile launchers – could be vulnerable to the kind of plane an 18-year-old pilot could book from their flying club.

“The Russians did their best to play it down, which is unsurprising as it was a serious breach of Soviet air defence,” says Mike Bratby, an air defence expert at the Royal Aeronautical Society. “On the approaches to Moscow, there was some very busy air space and a major concentration of fighter bases, radars and surface to air missile sites, all supposedly on alert against any threat from Western Europe. Rust evaded it all by flying his Cessna at roof-top height, then added insult to injury by landing in Red Square, virtually on the steps of the Kremlin.

“It highlighted the problem at the time of the Soviet air defence in reacting to a small, slow and low flying intruder, doing something completely unexpected, but in the aftermath – which included sacking senior Soviet commanders – Nato didn't advertise the fact that Western air defence systems suffered from similar problems trying to track small, low-flying aircraft.”

At least Rust’s Cessna will not be causing any more international incidents. It changed hands several times after the Soviets returned it to Rust’s flying club. It now hangs from the ceiling of the Deutches Technikmuseum in Berlin – a symbol of one audacious pilot’s attempt to improve relations between East and West.

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