Thirty-four years ago tonight, a little after half past six, a Boeing 747 freighter fell out of the sky over Amsterdam and into a block of flats. El Al Flight 1862 had taken off from Schiphol just over thirteen minutes earlier. Both engines on its right wing were already lying at the bottom of a lake.

The Bijlmer disaster of 4 October 1992, the Bijlmerramp in Dutch, killed at least 47 people: the three crew and one passenger on board, and 43 on the ground. It remains the deadliest air accident in Dutch history.

It also became a lesson in how a small, hidden crack in a single metal pin could bring down the biggest airliner in the world, and how a disaster can keep claiming victims long after the fires are out.

Two engines gone over the Gooimeer

Flight 1862 was a cargo run from New York to Tel Aviv with a stop at Schiphol. On board were Captain Yitzhak Fuchs, 59, a former Israeli Air Force fighter-bomber pilot with more than 25,000 hours; First Officer Arnon Ohad, 32; Flight Engineer Gedalya Sofer, 61; and one passenger, Anat Solomon, a 23-year-old El Al employee travelling home to Israel to get married.

The jet left runway 01L at 18:22 and turned right. Five minutes later, climbing through about 1,950 metres over the Gooimeer lake, witnesses heard a sharp bang. The No. 3 engine, the inboard engine on the right wing, had broken away, shot forward, and then swung back into the No. 4 engine, tearing it off too. Both engines fell into the lake, taking a ten-metre section of the wing's leading edge with them. A boater who saw them fall said he first thought they were parachutists.

The Air Crash Investigation episode on El Al Flight 1862, the most-watched documentary on the disaster.

The first officer called Mayday. Nobody on the flight deck yet knew the engines were physically gone; from the cockpit of a 747, the inboard engine cannot be seen at all, and it was getting dark.

Eight minutes of fighting a broken wing

The crew asked to land on runway 27, even with a tailwind of more than 20 knots. They were too high and too close on the first pass and had to circle Amsterdam to lose height. That circle doomed them.

At around 280 knots the damaged right wing still produced enough lift. But to land, the crew had to slow down and extend the flaps. With the No. 4 engine gone, its hydraulic system was dead too, so the outboard flaps would not deploy, and the torn leading edge meant the right wing's slats would not come out either. As the 747 slowed, the left wing produced far more lift than the right. The aircraft rolled right, and nothing the pilots could do would stop it.

At 18:35:25 the first officer radioed that they were going down. Seventeen seconds later, rolled nearly 90 degrees, the 747 struck the corner where two eleven-storey apartment blocks met, exploding in a fireball that consumed all eleven floors along a front about 120 metres wide.

A neighbourhood on fire

Police initially feared more than 200 dead. The blocks housed many residents from Suriname, Aruba and Ghana, some of them undocumented, and the official toll of 43 people killed on the ground has been doubted ever since.

Investigators traced the cause to the fuse pins that attach a 747 engine pylon to the wing. They are designed to shear cleanly under extreme loads so that an engine can fall away without damaging the wing. On 4X-AXG, fatigue cracks had already formed in the pins. The Netherlands Aviation Safety Board concluded that the design and certification of the 747 pylon had been inadequate and that inspections had failed to catch the problem, findings that fed into a programme of pylon and fuse-pin modifications on the 747 fleet.

The aftermath that would not end

The disaster did not stop at the crash site. Within a year, residents and rescue workers began reporting illnesses they linked to the crash. Authorities at first insisted nothing dangerous had been on board, until it emerged that the 747 carried depleted uranium as tail counterweight, as all 747s did at the time.

In 1998 El Al confirmed the cargo had included 190 litres of dimethyl methylphosphonate, a chemical that can be used to make the nerve agent sarin, shipped legally from the United States to the Israel Institute for Biological Research. A Dutch parliamentary inquiry followed. Every year since, the neighbourhood marks the anniversary, and no aircraft fly over the area for an hour.

The NOS Journaal news broadcast of the evening of 4 October 1992, as the Netherlands learned what had happened in the Bijlmer.

Green Dot Aviation's animated reconstruction of how the two engines separated and why the crew could not hold the wings level.

Sources: Netherlands Aviation Safety Board final report, Dutch parliamentary inquiry, Wikipedia, Air Crash Investigation, NOS