These are Star Wars/Skywalker Sound sound effects that debuted in Star Wars: Episode V - The Empire Strikes Back (1980). It mostly consists of SKYWALKER, AIRPLANE - INERTIA STARTER, BIPLANE and sounds very close to the beginning of SKYWALKER HYPERDRIVE FAILURE SOUND. Links: https://soundeffects.fandom.com/wiki/SKYWALKER,_SCI-FI_GUN_-_AT-AT_GUN/Audio_Samples