; (5) the date of approval of the relevant type design and the date of issuance of the airworthiness directive; (6) any corrective action mandated to address the identified unsafe condition; (7) the period of time specified for the incorporation of the corrective action, during which the affected transport airplanes were allowed to operate before the unsafe condition was corrected; and (8) the total cost of compliance estimated in the final rule adopting the airworthiness directive. (d) Coordination In conducting the study under subsection (a), the federally funded research and development center shall coordinate with, and solicit comments from— (1) transport category aircraft manufacturers; and (2) employees of the Administration, including the official bargaining representative of aircraft certification services engineers and of aviation safety engineers under section 7111 of title 5, United States Code, involved in developing airworthiness directives, as necessary. (e) Report to Congress Not later than 2 years after the date of enactment of this Act, the Administrator shall submit to the appropriate committees of Congress a report that includes— (1) the results of the study conducted under subsection (a); (2) actions the Administrator determines necessary to improve safety as a result of the findings under subsection (a) and any root causes of an unsafe condition that were identified; (3) the comments solicited under subsection (d); and (4) any other recommendations for legislative or administrative action determined appropriate by the Administrator. (f) Definitions In this section: (1) Air carrier