Aviation
The first aircraft to go missing in Bass Strait was a military Airco DH.9A that was engaged in a search for the missing schooner Amelia J in 1920 — it was believed to have gone into the sea off the southern coast of Flinders Island.
One of the first Bass Strait airliners, the De Havilland Express Miss Hobart, went missing soon after entering service in 1934, only a small amount of wreckage being found on the Victorian coast. A year later, a similar aircraft was lost with all on board off Flinders Island. The cause of both accidents was probably a combination of human error with the known poor design of the aircraft.
During the Second World War, several aircraft — mostly RAAF Bristol Beaufort bombers — were lost during exercises in Bass Strait while on training flights out of air bases, mostly Sale, Victoria. These accidents were probably caused by the inexperienced crew crashing into the sea while performing low-level bombing practice — similar accidents occurred over land.
In 1972, a De Havilland Tiger Moth flown by Brenda Hean and Max Price went missing while on a flight from Tasmania to Canberra as part of protests against the flooding of Lake Pedder for a hydroelectricity scheme. It was believed to have crashed at sea somewhere between the East Coast and Flinders Island. Sabotage by pro-development interests was alleged.
The most famous incident, and the one that has been the inspiration for paranormal explanations, was the Valentich Disappearance in 1978.
Read more about this topic: Bass Strait Triangle, History of Incidents