; (9) the potential changes in separation standards, fuel consumption, flight paths, block times, and landing procedures or lack thereof; (10) the potential impacts on aircraft taxi times and aircraft emissions or lack thereof; (11) a determination of the total potential costs and logistical challenges of the failure of NextGen, including a comparison of the potential loss of the return on public and private sector investment related to NextGen, as compared to other available investment alternatives, between December 12, 2003, and the date of enactment of this Act; and (12) other matters arising in the course of the study. (c) Report Not later than 1 year after the date of initiation of the study under subsection (a), the inspector general shall submit to the appropriate committees of Congress a report on the results of the study. 535. Study on allergic reactions Not later than 120 days after the date of enactment of this Act, the Administrator shall— (1) study the prevalence of allergic reactions on board flights, whether airlines universally report reactions to the Federal Aviation Administration, and the frequency of first aid inventory checks to ensure medicine to prevent anaphylactic shock is in an aircraft