ČSA Flight 523, operated by an Ilyushin Il-18D, was a scheduled flight from Prague Ruzyně International Airport (PRG/LKPR), Czechoslovakia to Havana via Shannon Airport and Gander International Airport, with 69 people on board, on 5 September 1967 it crashed on climb-out from Gander.

The aircraft struck a supporting wire of a mast,[1] climbed to 40 m (130 ft), then started to dive, hitting the ground at a speed of approximately 360 km/h (220 mph; 190 kn), hit a railway embankment 4,000 ft (1,200 m) past the end of the runway, caught fire and broke into pieces.

[2] The investigation of the incident started immediately; Czechoslovak and Soviet experts, including Genrikh Novozhilov from Ilyushin and the Czech World War II fighter pilot František Fajtl, also took part in it.

[2] As the accident occurred during Expo 67 in Montreal, the Czechoslovakian government afterwards donated its Expo pavilion to the government of Newfoundland as a gesture of gratitude for rescue efforts following the crash.

[3] In 2015 a memorial plaque was unveiled in Gander to honour the crash victims.