Forty years ago: Terrorist attack downs Swissair flight

"This is the only crash that was a terrorist action involving Swissair," Ronan Hubert, head of the Geneva-based Aircraft Crashes Record Office, told Swisster. "I have the final report."

Forty years ago on Sunday, the Convair CV-990-30A-6 Coronado Swissair flight crashed minutes after takeoff from Zurich-Kloten Airport.

Carrying 38 passengers and 9 crew members, the plane departed runway 28 at 1.14pm. It was raining.

Seven minutes later, the pilot radioed air traffic controllers with news that a blast had taken place in the left cargo compartment as the plane was over Lucerne.

The 46-year-old said he was losing pressure and asked permission to return to the airport and make an emergency landing.

Struggling to control the Coronado, the pilot reported that he had lost the use of several instruments and electrical systems.

The cabin filled with smoke reducing visibility to zero, as confirmed by recorded comments from the co-pilot.

As air traffic controllers attempted to guide the plane back to Zurich suddenly the pilot exclaimed: "We’re falling, goodbye everyone."

The plane performed a 180 degree turn before losing altitude and plunging into the heart of a forest near Würenlingen in canton Aargau.

Former Swissair spokesman, Jean-Claude Donzel remembers: "I was a trainee in London at the time. My early shift colleague told me about the disaster."

"We had some passengers flying from London to Tel Aviv on the morning flight and they were very scared," he told Swisster.

Rescue teams arriving at the crash scene were greeted with wreckage and no survivors.

Uncertainly still surrounds the question of who was responsible.

According to the Swiss report seen by Swisster, a Palestinian splinter group lead by Khalil al-Wazir (known as Abu Jihad), claimed responsibility for an attack designed to kill 15 senior Israeli officials on board.

However, at the time al-Wazir appears to enjoyed close links with the dominant Palestinian Liberation Organization and later became Yasser Arafat's right-hand man.

Other reports have the Popular Front for the Liberation of Palestine admitting the action, with Reuters later posting a denial from a group spokesman.

Nine Germans, five Americans, two Canadians, two Mexicans, one Belgian, one French, one British, one Thai and one Swiss made up the rest of the ill-fated passenger list.

The perpetrators were never brought to justice and Swiss officials running the investigation are no longer available for comment but Donzel questions whether the Israelis on board were specifically targeted by the bombers. "I think it was just bad luck. The bomb was a posted parcel destined for Tel-Aviv," he said.

"I don’t know whether it should have been on our flight or not. Parcels are not specified to individual flights."

Investigators found that IED bomb linked to an altimeter triggered the device – a technique often employed by the Popular Front – when the aircraft reached a height of 14,000 feet.

"Flames resulting from the explosion damaged part of the generator, creating several short-circuits that made it impossible to continue flying the aircraft," concluded the final report.

Although not up to today’s standards, security had been tightened at Swiss airports the previous year after a terrorist shooting in Zurich, Donzel said.

In December 1969, three Palestinians were sentenced to 12 years imprisonment by a Swiss court, a decision which caused considerable anger throughout the Arab world.

Looking back at the crash 40 years later, Donzel said: “It was a real shock for the company. If you have a accident with technical problems you can always say we could have done better, but with an incident like this, there was nothing we could have done.”

On Saturday in Würenlingen, a film to commemorate those that died in the bombing was shown. Expat John F. Crawford attended. "The crash is still remembered. My way to work takes me past the memorial. There are fresh flowers there this morning," he told Swisster on Monday.

February 21, 1970 was a dark day in aviation history. On the same day, another device detonated on board a Vienna-bound Caravelle aircraft after takeoff from Frankfurt.

Unlike the Swissair flight however, the Caravelle landed safely.