LOT Polish Airlines Flight 007


LOT Polish Airlines Flight 007 was an Ilyushin Il-62 that crashed near Warsaw-Okecie Airport in Poland, on 14 March 1980, as the crew aborted a landing and attempted to go-around, killing all 77 passengers and 10 crew members on board. It was caused by the disintegration of a turbine disc in one of the plane's engines, leading to uncontained engine failure. The turbine shaft was later found to have manufacturing faults.

Aircraft, crew, and passengers

initiated its transatlantic routes in 1973, for which it decided to purchase Ilyushin Il-62s. The aircraft that crashed was the first Il-62 that LOT had purchased for these routes, manufactured in 1971. The crashed plane, registered as SP-LAA, was at one point named after astronomer Nicolaus Copernicus.
All of the crew members of Flight 007 were Polish. The captain, Paweł Lipowczan, was 46 years old, with 8,770 flight hours' experience, half of them on Ilyushin Il-62s. The first officer was Tadeusz Łochocki. The remaining flight crew were flight engineer Jan Łubniewski, flight navigator Konstanty Chorzewski, and radio operator Stefan Wąsiewicz. There were five flight attendants on board.
Future world heavyweight champion boxer Tony Tucker was supposed to be on Flight 007 but could not go because of a shoulder injury. All 87 people on board were killed, including 14 boxers and 8 staff members of the U.S. boxing team, and Polish pop singer Anna Jantar.

Accident

On its final flight, the aircraft was piloted by Captain Lipowczan and First Officer Łochocki. Flight 007 was scheduled to depart from New York's Kennedy International Airport at about 19:00 local time on 13 March 1980, but it was delayed because of a heavy snowstorm. It finally departed at 21:18, and after nine hours of an uneventful flight, it was approaching Warsaw-Okęcie Airport at 11:13 local time. During their final approach, about one minute before the landing, the crew reported to Okęcie Air Traffic Control that the landing gear indicator light was not operating, and that they would go around and allow the flight engineer to check if it was caused by a burnt-out fuse or light bulb, or if there was actually some problem with the gears deploying.
This was the last transmission from LOT 007.
Nine seconds later, the aircraft suddenly entered a steep dive. At 11:14:35, after 26 seconds of uncontrolled descent, the aircraft clipped a tree with its right wing and impacted the ice-covered moat of a 19th-century military fortress at a speed of approximately at a 20-degree down angle, from the runway threshold and from a residential area. According to investigators analyzing the wreckage, at the last moment Captain Lipowczan, using nothing but the plane's ailerons, managed to avoid hitting a correctional facility for teenagers located at Rozwojowa Street. On impact, the aircraft disintegrated; a large part of the main hull submerged in the moat, while the tail and parts of the main landing gear landed some metres further, just before the entrance to the fort. On the scene, a diving team was later trying to recover parts of the aircraft from the moat, but it was far too murky. Ultimately, the moat had to be drained to allow the investigators to recover parts of the disintegrated plane. The body of Captain Lipowczan was found lying on the street about from the crash site; other bodies were scattered among the plane parts. The majority of the victims were found to be bisected due to seat belts being fastened at the time of impact.
Among the 87 fatalities were Polish singer Anna Jantar, American ethnomusicologist Alan P. Merriam, six Polish students returning home from an AIESEC conference in New York, and a contingent of the U.S. amateur boxing team. According to doctors who arrived at the scene, many of the passengers were apparently asleep when the plane hit the ground, but some of them – including many of the boxers – were supposedly aware that they were about to crash, as they gripped their seats so tightly that on impact, the muscles and tendons in their arms became severed. Some reports suggested that some of the boxers actually survived the crash and drowned in the moat, but no evidence for this was presented. A total of 22 U.S. boxers, trainers, and doctors died in the accident, including the 1979 Pan American Games light welterweight winner Lemuel Steeples. A number of Olympic team members were not on the flight due to various boxing injuries or other reasons.
NationalityPassengersCrewTotal
Poland421052
United States28028
Soviet Union404
East Germany303
Total771087

Investigation

Recovery of wreckage

The police quickly surrounded the site and removed spectators. Recovery of airplane pieces and victims started soon afterwards. Both the cockpit voice recorder and flight data recorder were found quickly. However, the recordings suddenly stopped nine seconds after the last radio transmission, 26 seconds before the crash.
The landing gear was found to be properly extended and locked. The Polish TV documentary Czarny serial interviewed Captain Tomasz Smolicz, a pilot who flew thousands of hours on transatlantic Ilyushins Il-62 and Il-62M, including SP-LAA's flight from Warsaw to New York the day before the crash. Smolicz stated that the planes returning to Warsaw from the United States usually landed on runway course 150, and if they landed at or before noon on a sunny day such as 14 March 1980, the sun would be shining almost directly in their eyes, which were weary after several hours of night flight and constant monitoring of cockpit instruments. This sometimes caused disorientation and confusion if an indicator light actually was lit or not. So, on that day, the landing gear indicator could have actually been lit, but the crew members might not have seen it correctly.
Upon recovery of the airplane parts, engine 2 was found to be cut in half, held together only by the fuel lines. When the engine was further examined, the disc of the low-pressure turbine was missing, despite an extensive search of the crash site. Finally, the turbine disc was found about from the site; it was broken into three similar-sized pieces.
After recovering the cockpit, the throttles of both engines 2 and 3 were found to be shut off, while engine 4 was set to maximum thrust. The investigating commission asked the Soviets if an Il-62 was able to reach the runway with one engine operating. No conclusive answer was received, but calculations based on the official technical data suggested that, while one engine's thrust was insufficient for the aircraft to maintain altitude, it was enough to reach the runway and try to land. No immediate explanation was found for why the aircraft experienced a steep dive with one engine operating at maximum power.
Detailed analysis of the three pieces of the turbine disc found several metallic impurities on the edges of two of them. In one case, they were identified as coming from the engine nacelle; in another, the impurities came from the nacelle, the hull, control actuators, and electrical cables. Also, detailed examination of the surface of the broken disc showed significant evidence of fatigue cracking.

Sequence of events

Finally, when the control pushers were found to be cut in half, and it was proven that the cut was not caused by the crash, and some traces of the turbine disc's metal alloy were found on the surface of the cut, the sequence of events became clear. The disaster started when LOT 007 was instructed to climb to a higher flight level, for its second approach to the runway. When the necessary thrust was applied to all four engines, the low-pressure turbine of engine 2 disintegrated after nine seconds. One piece of the turbine disc was ejected upwards, not causing any significant damage. The second piece shot into engine 1, damaging it seriously. The third piece of the disc shot into the hull, severed the rudder and elevator control rods and destroyed engine 3, causing loss of control over the plane. The third piece also severed power cables for both the flight data recorder and the cockpit voice recorder, causing the last moments of LOT 007 not to be recorded.
The cut control rods also explained the sudden dive. When they were cut, the tail section's horizontal stabilizer, under its own weight, dropped down, causing the nose also to go down. This could be counteracted by the vertical trim; in Il-62s, the switch setting the vertical trim to manual operation was secured by a thin, sharp wire. On Captain Lipowczan's right hand, small wounds were found, and they were confirmed to be made while Lipowczan was still alive. Supposedly, he ripped off the security wire and tried to control the vertical trim, but it was too late.

Causes of disaster

According to the Polish government's Special Disaster Commission, the crash was caused by defects in materials, faults in the manufacturing process of the Kuznetsov NK-8 jet engine's shaft, and weaknesses in the design of its turbine. The NK-8 is a two-spool turbofan engine, with two low-pressure turbines driving the fan and low-pressure compressor, and one high-pressure turbine driving the higher stages of the compressor.
During manufacture of the low-pressure shaft, at a position where its section diameter increases, a sharp, 90-degree step was made, resulting in a sudden diameter change over a very short linear length – a classic "notch" condition for stress concentration, which results in fatigue cracking at that location. Additionally, the metallurgical analysis found that the shaft was incorrectly heat-treated during manufacture and contained contaminant particles such as non-metallic inclusions, which further reduced the shaft's ability to carry the torsional loads as designed. The improper machining and impurities facilitated an accelerated fatigue fracture of this key engine component via unmitigated formation of micro-cracks through the shaft's core, ultimately leading to its failure.
Over time, the defects in the turbine shaft became large enough and the shaft broke, resulting in the physical separation of the low-pressure turbine from the low-pressure compressor. As a result, the low-pressure turbine explosively disintegrated. Ejected with enormous force, pieces of the turbines damaged two further engines and cut through the hull. This caused the failure of the vertical and horizontal flight controls, and a catastrophic failure of numerous systems of the aircraft. The sudden loss of control of the flight control surfaces caused a steep, unrecoverable dive and resulted in the crash, 26 seconds after the original engine failure.