What happened
A four-engine Tupolev Tu-154 departed from Berlin-Schönefeld Airport at 16:30 local time, operating a charter service bound for Burgas. The flight was carrying 148 passengers and eight crew members. Approximately thirteen minutes into the flight, while maintaining an altitude of 29,200 feet, the crew notified air traffic control of mechanical difficulties and received permission to return to Berlin.
At 16:51 local time, the crew initiated fuel dumping procedures. As the technical situation deteriorated, the captain began an emergency descent three minutes later. By 16:59 local time, the pilot reported a fire on board and indicated that the aircraft was becoming difficult to control. Shortly thereafter, the empennage separated from the main fuselage. The uncontrolled aircraft descended into a forested region in Königs Wusterhausen, roughly 11 km southeast of the departure airport. The impact resulted in a massive fire, causing the total destruction of the aircraft and 156 fatalities, with no survivors recorded.
Findings
Investigations determined that a leak had existed in a hot-air tube located at the rear of the aircraft for an extended period. The high temperatures from this leaking air, reaching approximately 300 degrees Celsius, degraded the insulation on electrical wiring and flight control components. Following takeoff, an electrical short-circuit occurred, producing sparks as hot as 2000 degrees Celsius. This ignited a fire within the number 4 cargo bay. The intense heat from the fire compromised the structural integrity of the fuselage, leading to the separation of the tail section during flight.