He worked as a pilot with the Far Eastern department of the Civil Air Fleet. After February 13, 1934, when the steamship "Cheliuskin" sunk in Arctic waters, Liapidevsky, in extremely difficult conditions, took part in aerial search and rescue of its crew (known as "Cheliuskintsi"). He flew the stranded "Cheliuskintsi" from their makeshift airstrip on the floating ice field to the town of Uelen. Liapidevsky was awarded the title of the Hero of the Soviet Union for this deed.
During the World War 2 he served as the deputy commander of the Air Forces of the 19th Army, and the chief of the field region of the 7th Air Army.