; and (D) entering into the contract would not compromise aviation security or the effectiveness of the screening of passengers or property at the airport. ; (D) in paragraph (2), as redesignated, by striking the second sentence; and (E) by adding at the end the following: (3) Training and certification (A) In general A private screening company may fulfill the requirement under paragraph (1)(A) by using screening supervisors who have been trained and certified at a Federal Law Enforcement Training Center to administer comparable on-site training and certification to private security screeners at an airport that is participating in the screening partnership program. (B) Authorized trainers If a private screening company elects to conduct on-site training and certification in accordance with subparagraph (A), such training shall be conducted by— (i) a Federal employer or contractor who is authorized to train and certify security screeners; or (ii) an employee of a private screening company who has successfully completed security supervisor training at a Federal Law Enforcement Training Center. (C) Rule of construction Nothing in this paragraph may be construed to require security screeners employed by a private screening company who have received on-site training and certification in accordance with subparagraph (A) to receive any additional training at a Federal Law Enforcement Training Center. (4) Part-time positions None of the standards required to be a qualified private screening company may be construed to prohibit a private screening company from employing screeners for part-time positions. (5) Calculation of federal costs For purpose of the comparison of costs required under paragraph (1)(C), the Administrator shall incorporate a cost estimate that reflects the total cost to the Federal Government, including all costs incurred by all Federal agencies and not only by the Transportation Security Administration, of providing screening services at an airport.