Sometimes there are no traces left behind. In 1947, Avro Lancastrian airliner flew into a mountain in the Andes and triggered an avalanche that buried the wreck

Sometimes there are no traces left behind. In 1947, Avro Lancastrian airliner flew into a mountain in the Andes and triggered an avalanche that buried the wreck. Compressed snow slowly turned into ice and became a part of the glacier. Over the next 50 years, the wreck moved down the mountain with ice until it eventually melted and revealed parts of the aircraft. They were found by two mountaineers in 1998. https://en.wikipedia.org/wiki/1947_BSAA_Avro_Lancastrian_Star_Dust_accident https://en.wikipedia.org/wiki/1947_BSAA_Avro_Lancastrian_Sta... If an aircraft goes missing, we're usually dealing with mountains, oceans or remote areas with dense tree covers. Remote sensing is very limited in these environments.