This is the 2151st most frequent Russian word.
беспилотных
"Unmanned" or "pilotless."
In this sentence, 'беспилотных' serves as an adjective describing 'летательных аппаратов', indicating they are flying devices without pilots.
Испытания беспилотных летательных аппаратов проводились на закрытой территории.
Tests of unmanned aerial vehicles were conducted in a restricted area.
Here, 'беспилотных' qualifies 'роботов', meaning the robots operate without direct human control or presence.
Беспилотных роботов начали использовать в промышленности.
Unmanned robots began to be used in industry.
Here, 'беспилотных' modifies 'автомобилей', and the word is used as an adjective meaning 'unmanned'.