Table of Contents United States Securities and Exchange Commission Washington, D.C. 20549 FORM 10-Q ý Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the Quarterly Period Ended December 31, 2018 or ¨ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the Transition Period From _________ to ________ Commission File Number: 1-12235 TRIUMPH GROUP, INC. (Exact name of registrant as specified in its charter) (State or other jur ...