1933
March 28 – The 1933 Imperial Airways Dixmude crash in Belgium of an Armstrong Whitworth Argosy II is the first suspected case of air sabotage; all 15 on board are killed.
October 10 – United Air Lines Trip 23, a Boeing 247, is destroyed by a bomb over Chesterton, Indiana, United States, in the first proven case of air sabotage on a commercial aircraft; all seven on board are killed.
tf was going on in 1933?
Anarcho-socialist terrorism…it was a pretty big deal in the USA early 20th century google propaganda of the deed… its pretty interesting stuff