Twin Engine Helicopter. The AgustaWestland AW109S, commonly known as the Agusta 109S, is a versatile and sophisticated twin-engine helicopter that stands out for its exceptional performance, luxurious features, and adaptability across various missions. Designed and manufactured by Leonardo S.p.A., an Italian aerospace company, the Agusta 109S has gained a reputation as a top-tier helicopter in the light twin-engine category.