On 4 October 1992, El Al Flight 1862, a Boeing 747-200 cargo aircraft of the Israeli airline El Al, crashed into the Groeneveen and Klein-Kruitberg flats in the Bijlmermeer (colloquially "Bijlmer") neighbourhood of Amsterdam, the Netherlands. The accident is known in Dutch as the Bijlmerramp ("Bijlmer disaster"). The subsequent health effects in survivors, and eventual revelations of the cargo manifest, showed at least three chemical precursors used in the production of the nerve agents sarin and soman.
Forty-seven people are known to have been killed, including all 4 on board and 43 on the ground. The exact number killed on the ground is uncertain, as the building housed many unregistered residents. Eleven people were seriously injured and 15 received minor injuries. The accident is the deadliest aviation disaster to have occurred in the Netherlands.
In 1998, El Al spokesman Nachman Klieman publicly revealed the aircraft was carrying 190 liters of dimethyl methylphosphonate (DMMP), later a Schedule 2 chemical under the 1993 Chemical Weapons Convention, that can be used to produce nerve agents including sarin and soman. According to Jean Pascal Zanders, a European Union Institute for Security Studies scholar, DMMP was one of three sarin precursors on board, and sarin requires four precursors. The shipment was from a U.S. chemical plant to the Israel Institute for Biological Research under a U.S. Department of Commerce license, in accordance with international regulations at the time.
Aircraft
The aircraft involved was a Boeing 747-258F, MSN 21737, registered as 4X-AXG manufactured on 7 March 1979. At the time of the crash, the 13-year old aircraft still had at least 5 years of useful service before retirement. It had flown 45,746 hours and completed 10,107 flight cycles. It was equipped with four Pratt & Whitney JT9D-7J engines.
Accident
On 4 October 1992, the cargo aircraft, a Boeing 747-258F, registered as 4X-AXG, travelling from John F. Kennedy International Airport in New York to Ben Gurion International Airport in Israel, made a stopover at Amsterdam Schiphol Airport. During the flight from New York to Schiphol, three issues were noted: fluctuations in the autopilot speed regulation, problems with a radio, and fluctuations in the voltage of the electrical generator on engine number three, the inboard engine on the right wing that would later detach from the aircraft and initiate the accident.
The jet landed in Schiphol at 14:40 for cargo loading and crew change. The aircraft was refuelled and the observed issues were repaired, at least provisionally. The crew consisted of Captain Yitzhak Fuchs (59), First Officer Arnon Ohad (32), and Flight Engineer Gedalya Sofer (61). A single passenger named Anat Solomon (23) was on board. She was an El Al employee based in Amsterdam, and was travelling to Tel Aviv to marry another El Al employee. Captain Fuchs was an experienced aviator, having flown as a fighter-bomber pilot in the Israeli Air Force in the late 1950s. He had over 25,000 flight hours, including 9,500 hours on the Boeing 747. First Officer Ohad had less experience than the other two crew members, having logged 4,288 flight hours, 612 of them on the Boeing 747. Flight Engineer Sofer was the most experienced crew member on the flight, with more than 26,000 hours of flight experience, of which 15,000 were on the Boeing 747.
Captain Fuchs had flown for El Al for 28 years (since 1964) and had previously served in the Israeli Air Force for 10 years. First Officer Ohad had flown for El Al for 10 years (since 1982), and Flight Engineer Sofer for 37 years (since 1955).
Flight
El Al Flight 1862 was scheduled to depart at 17:30, but was delayed until 18:20. It departed from runway 01L Zwanenburgbaan (now known as runway 36C) on a northerly heading at 18:22. Once airborne, the aircraft turned to the right. Soon after the turn, at 18:27, above the Gooimeer, a lake near Amsterdam, witnesses on the ground heard a sharp bang and saw falling debris, a trail of smoke, and a momentary flash of fire on the right wing while the aircraft was climbing through 1,950 m (6,400 ft). The No. 3 (inner right) engine separated from the right wing of the aircraft, shot forward, damaged the wing slats, then fell back and struck the No. 4 (outer right) engine, tearing it from the wing. The two engines fell away from the aircraft, also ripping out a 10 m (33 ft) stretch of the wing's leading edge. The loud noise attracted the attention of some pleasure boaters on the Gooimeer. The boaters notified the Netherlands Coastguard of two objects they had seen falling from the sky. One boater, a police officer, said he initially thought the two falling objects were parachutists, but as they fell closer he could see that they were plane engines.
The first officer made a Mayday call to air traffic control (ATC) and indicated that they wanted to return to Schiphol. At 18:28:45, the first officer reported: "El Al 1862, lost number three and number four engine, number three and number four engine." ATC and the flight crew had not yet grasped the severity of the situation. Although the flight crew knew they had lost power from the engines, they had not realized that the engines themselves had completely broken off and that the wing had been damaged. Later the media asked if the pilots could have been aware of the engines having broken off. After tests, it was found that the outboard engine on the wing of a 747 is visible from the cockpit only with difficulty and the inboard engine on the wing is not visible at all (and this is in clear weather; given the time of year and day, it was also getting dark, hampering visibility even further). Given the choices the captain and crew made following the loss of engine power, the Dutch parliamentary inquiry commission that later studied the crash concluded that the crew did not know that both engines had broken away from the right wing.
On the evening of the crash, the landing runway in use at Schiphol was runway 06 (called the Kaagbaan; the airport's standard runway for night-time operations due to lower noise impact on the ground). In this specific instance, it was also positioned favourably against the wind coming from direction 040 degrees. However, the crew requested runway 27 for an emergency landing, even though it meant landing with a 21-knot (11 m/s; 39 km/h; 24 mph) quartering tailwind.
The aircraft was still too high and too close to land when it first circled back to the airport. It was forced to continue circling Amsterdam to reduce its altitude to that required for a final approach to landing. During the second circle, the wing flaps were extended. The inboard trailing edge flaps extended (since they were powered by the number one hydraulic system, which was still functioning), but the outboard trailing edge flaps did not (since they were powered by the number four hydraulic system, which had failed when the number four engine broke away). The leading edge slats extended on the left wing, but not on the right wing, because of the extensive damage sustained when the engines separated, which had also severely disrupted the air flow over the right wing. That differential configuration caused the left wing to generate significantly more lift than the right, especially when the pitch altitude increased as the airspeed decreased, increasing the aircraft's tendency to roll further to the right, both because the right outboard aileron was inoperative and because the thrust of the left engines was increased in an attempt to reduce the aircraft's very high sink rate. As the aircraft slowed, the ability of the remaining controls to counteract the right roll diminished. The crew finally lost almost all ability to prevent the aircraft from rolling to the right. The roll reached 90° just before the impact with the apartments.
At 18:35:25, the first officer radioed to ATC: "Going down, 1862, going down, going down, copied, going down." In the background, the captain was heard instructing the first officer in Hebrew to raise the flaps and lower the landing gear.
Crash
At 18:35:42 local time, the aircraft nose-dived from the sky and crashed into two high-rise apartment complexes in the Bijlmermeer neighbourhood of Amsterdam, at the corner of a building where the Groeneveen complex met the Klein-Kruitberg complex. It exploded in a fireball, which caused the building to partially collapse inward, destroying dozens of apartments. The cockpit came to rest east of the building, between the building and the viaduct of Amsterdam Metro Line 53; the tail broke off and was blown back by the force of the explosion.
During the last moments of the flight, the ATCs made several desperate attempts to contact the aircraft. The Schiphol arrival controllers work from a closed building at Schiphol-East, not from the control tower. At 18:35:45, the control tower reported to the arrival controllers: "Het is gebeurd" (literally "It has happened", but colloquially "It is over"). At that moment a large smoke plume emanating from the crash scene was visible from the control tower. The aircraft had disappeared from arrival control radar. The arrival controllers reported that the aircraft had last been located 1.5 km (0.9 mi; 0.8 nmi) west of Weesp, and emergency personnel were sent immediately.
At the time of the crash, two police officers were in Bijlmermeer checking on a burglary report. They saw the aircraft plummet and immediately sounded an alarm. The first fire trucks and rescue services arrived within a few minutes of the crash. Nearby hospitals were advised to prepare for hundreds of casualties as authorities were unsure if it was a cargo or passenger 747. The complex was partly inhabited by immigrants from Suriname and Aruba, both former Dutch colonies, and the death toll was difficult to estimate in the hours after the crash.
Aftermath
The crash was also witnessed by people in a nearby fire station on Flierbosdreef. First responders came upon a rapidly spreading fire of "gigantic proportions" that consumed all 11 floors of the buildings and was 120 metres (390 ft) wide. No one survived from the crash point, but some managed to escape from the remainder of the building. Witnesses reported seeing people jumping out of the building to escape the fire.
Hundreds of people were left homeless by the crash; the city's municipal buses were used to transport survivors to emergency shelters. Firefighters and police were also forced to deal with reports of looting in the area.
Prime Minister Ruud Lubbers and Queen Beatrix visited the scene of the disaster the following afternoon. The prime minister said, "This is a disaster that has shaken the whole country."
In the days immediately following the disaster, bodies of victims were recovered from the crash site. The mayor ordered rubble and aircraft wreckage removed, and investigators found the critical engine pylon fuse pins in the landfill. The two fallen engines were recovered from the Gooimeer, as were pieces of a 9-metre (30 ft) section of the right wing's leading edge. The remains of the aircraft were transported to Schiphol for analysis.
The aircraft's flight data recorder was recovered from the crash site and was heavily damaged, with the tape broken in four places. The section containing the data from the last two and a half minutes of the flight was particularly damaged. The recorder was sent to the United States for recovery and the data were successfully extracted. Despite intensive search activities to recover the cockpit voice recorder from the wreckage area, it was never found, though El Al employees stated that it had been installed in the aircraft.
Causes
When Boeing 747 engines or engine pylons experience excessive load, the fuse pins holding the engine nacelle to the wing are designed to fracture cleanly, allowing the engine to separate from the aircraft without damaging the wing or wing fuel tank. Airliners are generally designed to remain airworthy in the event of an engine failure or separation, so they can be landed safely.
However, damage to a wing or wing fuel tank can have disastrous consequences. The Netherlands Aviation Safety Board found that the fuse pins had not failed properly, but instead had fatigue cracks prior to overload failure. The board developed a scenario of a probable sequence of events for the loss of engine three:
- Gradual failure by fatigue and then overload failure of the inboard midspar fuse pin at the inboard thin-walled location
- Overload failure of the outer lug of the inboard midspar pylon fitting
- Overload failure of the outboard midspar fuse pin at the outboard thin-walled and fatigue-cracked location
- Overload failure of the outboard midspar fuse pin at the inboard thin-walled location
This sequence of consecutive failures caused the inboard engine and pylon to break free. Its trajectory after breaking off the wing caused it to slam into the outboard engine and rip it and its pylon off the wing. Serious damage was also caused to the leading edge of the right wing. Both loss of hydraulic power and damage to the right wing prevented correct operation of the flaps the crew later tried to extend in flight.