Abstract: An angle-adjusting sub-assembly (6) that is part of or attached to an unmanned aerial vehicle and apparatus (1), for the targeted distribution of hazardous chemicals onto vegetation, and is comprised of: adjustable arms (7), rotary system, which adjusts the length and angle of the adjustable arms while the aerial vehicle and apparatus are airborne. An unmanned aerial vehicle and apparatus, for the targeted distribution of hazardous chemicals onto vegetation, is comprised of: the angle-adjusting sub-assembly (6), a spray assembly, a flying platform, a storage tank (2) containing pesticide, bactericide, herbicide, fungicide, or any hazardous chemical that can be sprayed on vegetation, a supporting structure (4), and a landing sub-assembly. Using of the above device decreases the runoff of toxic chemical waste to the environment, increases chemical application efficiency, and allows for the precise targeting of pests on crops.