Delta Air Lines (DAL) 10-Q 2014 Q2 Quarterly report

Exhibit 15

July 23, 2014

To the Board of Directors and Stockholders of

Delta Air Lines, Inc.

We are aware of the incorporation by reference in the Registration Statements (Form S-8 No.’s 333-142424, 333-149308, 333-154818 and 333-151060) of Delta Air Lines, Inc. for the registration of shares of its common stock of our report dated July 23, 2014 relating to the unaudited condensed consolidated interim financial statements of Delta Air Lines, Inc. that are included in its Form 10-Q for the quarter ended June 30, 2014.

/s/ Ernst & Young LLP