In the late-morning hours of 9 May 1987, the Ilyushin Il-62M operating the flight crashed in the Kabaty Woods nature reserve on the outskirts of Warsaw around 56 minutes after departure.

[2] The aircraft was a 186-seat Ilyushin Il-62M built in the third quarter of 1983, registered SP-LBG and named after Tadeusz Kościuszko, a Polish military leader and national hero.

Five flight attendants were on board; one was stationed in the technical cabin bay, between the engines, and probably either lost consciousness and burned in the fire or was sucked out of the aircraft after decompression; her body was never found despite an extensive search.

Nine minutes after the thrust was applied, as the aircraft had just passed Lipinki village, near Warlubie (near Grudziądz), at 8,200 m (26,900 ft), at a speed of 810 km/h (440 kn; 500 mph)), the faulty bearings inside the number 2 engine reached temperatures of about 1,000 °C or 1,800 °F and exploded, destroying the shaft.

Immediately, the crew noticed that the elevator control systems had failed—only the pitch trim remained operative—and that two engines were disabled.

Initially, the crew intended to land at the military airport in Modlin, but at the final moment, they decided to return to Okęcie, which had better emergency equipment.

Instead, the cause was later determined to be the damage to the electrical systems preventing both the fire detectors in the cargo hold and inside the engine from working properly (on the cockpit voice recorder (CVR), an engine fire warning was heard shortly after the explosion, but it later faded out; the signal reappeared less than four minutes before the crash and continued until impact), so Cpt.

Pawlaczyk did not know about the magnitude of the fire in the hold and how quickly it was spreading, nor about the burning engine when he decided to fly to Warsaw.

The passengers were fully aware of the emergency; 58-year-old passenger Halina Domeracka managed to write on the opening page of her New Testament: "9.05.1987 The aircraft's damaged... God, what will happen now... Halina Domeracka, R. Tagore St., Warsaw..."[7][8][9][10] The crew tried to land at Okęcie from the south (due to strong wind) and turned the aircraft 180° to runway 33, but the rapidly spreading in-flight fire, which spread to the exterior of the aircraft (which was trailing a huge flame and dense black smoke), caused a total failure of surviving flight controls, including the pitch trim.

[citation needed] At the moment the aircraft passed the village of Józefosław, about 10 km (6.2 mi) from the airport, several burnt-out elements of its fuselage fell out, starting local fires on the ground.

When the aircraft passed the town of Piaseczno, it went into a sinusoid-shaped flight for the final seconds and nose-dived with a slight 11° left bank and 12° pitch downwards, crashing into the ground at 475 km/h (256 kn; 295 mph) and exploding into pieces in the forest 5,700 metres (18,700 ft) (about 3.5 miles (5.6 km)) from the Warsaw airport runway.

[citation needed] The fire also deformed the aft fuselage, which—combined with strong forces acting on the empennage—altered the aircraft's angle of attack and contributed to the rapid dive.

Because some burning pieces of hull fell out, several local fires were initiated on the ground, propagated by the dumped fuel; all of them were extinguished by 12:00.

Many officials from all over world, including Pope John Paul II, himself a Pole, expressed their condolences to the families of the victims.

Detection of these faults was possible only after complete disassembly of the engine and detailed analysis of all its elements, and as such was beyond the capabilities of aircraft maintenance personnel.

Ursynów district has a Zygmunt Pawlaczyk street, and through Kabaty Forest runs a grove of trees named for the Kościuszko.