The AHS International (The Vertical Flight Technical Society) database is sort of quirky. When doing a search and seeking to download a paper, a screen pops up and appears to be asking you to BUY the paper. But there is no cost. Note the price is $0.00 since UA has a subscription. Just click on “ADD TO CART” and “START CHECKOUT” next “CONTINUE” and then “COMPLETE ORDER.” A link will appear to the PDF of the paper.