The 74 passengers on board Flight LZ101 were of 12 nationalities: Bulgarians, Argentinians, Britons, Chileans, Czechoslovaks, Germans, Hondurans, Hungarians, Japanese, Soviets, Swiss and Tunisians.
Among them were Bulgarian opera soloist Katya Popova, Bulgaria's ambassador to the German Democratic Republic, General Ivan Buchvarov[2] and famous Honduran writer and journalist Ramón Amaya Amador.
The aircraft struck the snow-covered ground while flying without any bank angle, at a speed of some 250 knots (460 km/h; 290 mph) and while full take-off power was delivered by its engines.
The accident was observed and heard by many local residents, including an off-duty air traffic controller who immediately telephoned his colleagues at the airport.
Because of difficult terrain, total darkness and poor weather, rescue services failed to find the scene of the crash for an hour and a half after being summoned.
Most victims had died instantly due to multiple injuries received during the impact, and most had severe burn marks sustained post-mortem.
A Bulgarian commission of enquiry was also formed, headed by State Comptrol Commission chairman and BKP Bulgarian Communist Party Central Committee member Ninko Stefanov and also included TABSO Director General Lazar Beluhov, air specialist and deputy defence minister Gen Avgust Kabakchiev and Darzhavna Sigurnost (State Security) investigator Col Ivan Ohridski, chief police pathologist Dr Yordan Peychev and others, enough to fill two specially chartered aircraft.
The investigators documented that the local militia (police), Czechoslovak State Security and Bratislava Military Engineer School ranks searched an area of some 350 by 50 metres (1,150 by 160 ft) surrounding the accident site.
An advance TABSO party led by Beluhov had arrived at Bratislava the day after the crash but had been denied any access to the accident site or to any air traffic controllers.
The Bulgarian side believed that air traffic controllers in the local Tower and Approach sectors had neglected their duties in allowing a slower aircraft (the Il-14) to depart before a high-performance aircraft (the Il-18), in failing to clear flight LZ101 to a safe height, and in failing to monitor its progress on radar.
The Czechoslovak side believed that the flight crew had demonstrated poor comprehension of English by failing to turn right after lift-off, as instructed.
Dr Peychev insisted that a test recently developed by NASA be conducted on tissues taken from the Commander and Second Pilot; the results showed that they had not consumed alcohol.
The issues in the conflict touched national prestige and the amount of damages payable to the victims' families: if Czechoslovak air traffic control was found deficient, they would receive 20,000 US dollars each.
The Czechoslovak commission's eventual report[6] stated that departure from runway 31 followed by climb to 300 metres (980 ft) was possible without colliding with obstacles.
The situation became critical when the crew failed to execute the stipulated and acknowledged departure manoeuvre and when unpredictable circumstances may have arisen and accrued during the turn.
Largely because of the loss of Katya Popova, well known Bulgarian lyric soprano, it had a massive public resonance in Bulgaria.
The remains of the Bulgarian victims were ceremonially returned to Sofia and interred in the city's main cemetery, and all traffic was brought to a two-minute standstill when air-raid sirens sounded throughout Bulgaria.