Yes, rotorwash can be a problem. In Hawaii in the late '70’s my Infantry unit was in the field and a young soldier was standing atop an M561 Gama Goat holding up the sling to hook up to a hovering CH-47. When the aircraft was at the correct position the soldier was blown OFF the Goat. He shook himself off, got back on the vehicle, and completed the hookup. Later. after I got out, I eventually received my A&P and always remembered that incident when I worked at PHI in Louisiana.