SYDNEY, July 23 (AFP) – A pioneering Australian inventor whose ''black box'' flight data recorder revolutionized the safety of air travel and aided countless crash investigations has died aged 85, officials said Wednesday.

David Warren, whose own father died in a plane crash, hit upon the ''black box'' idea while probing a 1953 disaster involving the world's first commercial jetliner.

''Without any explanation, without any witnesses, without any survivors ... (it was) a really baffling mystery,'' Warren said in a 2003 interview.

Warren, who died on Monday, was the first European child born on Groote Eylandt, a remote Aboriginal island in Australia's northeast, in 1925.

His father was among 12 people on board the ''Miss Hobart'' mail plane that vanished over the southern Bass Strait in 1934, one of Australia's earliest air disasters.

Then just nine years of age, Warren was left with his father's last gift to him, a crystal radio set, which he used to listen to broadcasts after lights-out in his boarding school dormitory.

Building radios soon became his schoolboy hobby, but a World War II ban on amateur radio led Warren to dump his nascent ambitions as a ''radio ham'' in favor of chemistry, his ultimate career path.

He first hatched the idea of cockpit voice and data recording while investigating a 1953 crash of the Comet, the world's first commercial jet, basing his design on a miniature pocket recorder he had seen at a trade fair.

''I put the two ideas together,'' he said.

''If a businessman had been using one of these in the plane and we could find it in the wreckage and we played it back, we'd say, 'We know what caused this."

''Any sounds that were relevant to what was going on would be recorded and you could take them from the wreckage.''

After an initial lack of interest from authorities, Warren built a prototype ''black box'' in 1956. It was able to store four hours of voice recordings and instrument readings.

The idea was slow to catch on, with Australia's Department of Civil Aviation advising Warren that his ''instrument has little immediate direct use in civil aviation.''