; (2) commercial air service; (3) military flight activity; (4) emergency response activity; (5) commercial space launch and reentry activities; (6) weather; and (7) air traffic controller staffing. (c) Report Not later than 18 months after the initiation of the study under subsection (a), the Comptroller General shall submit to the appropriate committees of Congress a report on the results of the study and recommendations to reduce the impacts to scheduled air service transiting congested airspace. 616. Briefing on LIT VORTAC project (a) In general Not later than 180 days after the date of enactment of this Act, the Administrator shall brief the appropriate committees of Congress on the Little Rock Port Authority Very High Frequency Omni-Directional Radio Range Tactical Air Navigation Aid Project (in this section referred to as LIT VORTAC ). (b) Briefing contents The briefing required under subsection (a) shall include the following: (1) The status of the efforts by the FAA to relocate the LIT VORTAC. (2) The status of new flight planning of the relocated LIT VORTAC. (3) A description of and timeline for each remaining phase of the relocation of the LIT VORTAC. 617. Surface surveillance (a) In general Not later than 1 year after the date of enactment of this Act, the Administrator shall conduct a review of surface surveillance systems that are operational as of such date of enactment. (b) Contents In carrying out the review under subsection (a), the Administrator shall— (1) demonstrate that any change to the configuration of surface surveillance systems or decommissioning of a sensor from such systems provides an equivalent level of safety as the current system; (2) determine how a technology refresh of legacy sensor equipment can reduce operational and maintenance costs of surface surveillance systems compared to current costs and extend the useful life and affordability of such systems