Francisco Manuel Lumbrales de Sá Carneiro , GCTE , GCC , GCL ( ; 19 July 19344 December 1980 ) founded the Portuguese Social Democratic Party in 1974 ( the year of the Portuguese Carnation Revolution ) and became Prime Minister of Portugal in January 1980 , but only held office for eleven months , dying in a plane crash with his partner , " Snu " Abecassis ( born Ebba Merethe Seidenfaden ) , on 4 December 1980 . A parliamentary inquiry said in 2004 that there was evidence of a bomb in the aircraft , after a 1995 inquiry had concluded there was evidence of sabotage
plane crash
1980 Camarate air crash
Francisco de Sá Carneiro