Investigation Summary
The aircraft, one of three Vickers Viscounts recently acquired by LOT from British United Airways, was operating a multi-leg service from Brussels to Warsaw with a stopover in Berlin. At the time of the accident, the airframe had logged only 84 flight hours in LOT service. During the final approach to runway 33, the crew faced challenging meteorological conditions, including a temperature of -5°C, dense near-ground fog, and fractostratus clouds at 250 meters. The Chief Committee of Aircraft Accident Investigation found the aircraft was properly configured for landing with gear down and flaps set. However, the investigation highlighted a critical mismatch between the captain's extensive experience on piston-engine aircraft and the specific handling requirements of the Viscount's Rolls-Royce Dart turboprop engines. In turboprops, sudden power applications can cause significant changes in propeller pitch that may lead to a stall if the airspeed is already low. The committee concluded that such a maneuver was likely attempted during the final seconds of the flight, resulting in a fatal loss of control.
Final Conclusions
The official investigation cited crew error and training deficiencies as the primary causes of the accident. Specifically, the captain's lack of familiarity with turboprop engine characteristics led to an inappropriate throttle maneuver during a low-speed approach. Additionally, the investigation noted the possibility that a non-directional beacon (NDB) used for the approach may have been malfunctioning without the crew's knowledge, potentially complicating the final stages of the flight.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Turboprop Engine Pitch Control
Unlike piston engines, turboprop engines change propeller pitch during acceleration; sudden throttle increases at low speeds can cause aerodynamic issues or stalls if not managed correctly.
Non-Directional Beacon (NDB)
A ground-based radio transmitter used for navigation; investigators noted one NDB on the approach path may have been broken during the accident.
Interesting Facts
- 01The aircraft was one of three recently purchased from British United Airways.
- 02The airframe had only logged 84 flight hours with LOT Polish Airlines at the time of the crash.
- 03Weather conditions included dense near-ground fog and a temperature of -5°C.
- 04All 33 people on board, including 5 crew and 28 passengers, were killed.
- 05The investigation confirmed there was no mid-air explosion; all damage occurred upon impact.
Safety Actions & Advisories
Crew Transition Training
The investigation emphasized the need for better training when transitioning pilots from piston-engine aircraft to turboprop aircraft to account for different engine response characteristics.