Malaysia Airlines MH370, along with passengers and crew, vanished on March 8, 2014. A five-year-long search ensued. The formal surface and seafloor searches did not turn up debris; however, about 23 pieces of the aircraft eventually washed up on the South Indian Ocean islands of Madagascar, Mauritius, Reunion; and on various East African beaches extending from Kenya to South Africa.
In addition to a lengthy underwater search, various efforts were made to reverse-track some of the debris to determine where it originated. Three of those efforts placed the crash in Perth Basin, but search coordinators had concerns that reverse drift methods might lack precision. Hence, searches in Perth Basin were limited.
Then, in 2018, 54 preflight “test” pings between MH370 and its satellite were rediscovered. They didn’t add new information to the puzzle, but they served as a catalyst, prompting analysts to use “trilateration” to pinpoint the plane’s location on the final ping. Like triangulation, trilateration is an old technique that is widely used in business and industry. Both techniques are used in surveying; and, trilateration in particular is used to manufacture precision telescopes, microscopes, and lenses of all kinds, including prescription optical lenses.