NEW YORK (Standard&Poor's) Nov. 16, 2015--Standard&Poor's Ratings Services today assigned its 'AA (sf)' issue-level rating to United Airlines Inc.'s series 2015-1 class AA pass-through certificates (with an expected maturity date of Dec. 1, 2027). At the same time, we assigned our 'A (sf)' issue-level rating to the company's series 2015-1 class A pass-through certificates (with an expected maturity date of Dec. 1, 2022). The final legal maturities will be 18 months after the expected maturities. United Airlines is issuing the certificates under a Rule 415 shelf registration. These ratings are in-line with the preliminary ratings we assigned on Nov. 2, 2015. We base our ratings on these issues on the credit quality of United Airlines' parent,