; and (3) other mitigation as indicated by a community assessment under section 5(f) or an action plan under section 6 using the diagnostic tool developed by the National Academy of Sciences under section 3. (d) Sound insulation for communities subject to high flight frequency (1) In general Using the framework and diagnostic tool developed by the National Academy of Sciences under section 3, in carrying out an action plan described in section 6, the Administrator shall develop standards for determining which communities are subject to significant frequency of overhead flights, which shall be eligible for noise mitigation funding. (2) Noise mitigation In carrying out an action plan described in section 6, the Administrator and airport operators shall provide grants for noise mitigation for aviation-impacted communities that are subjected to a high frequency of flight operations or from the adoption of new flight procedures (as determined by the Administrator through the use of the framework and diagnostic tool developed by the National Academy of Sciences under section 3). (e) Sound insulation for residences impacted by significant night time aircraft noise In carrying out an action plan described in section 6, the Administrator and airport operators shall provide noise mitigation for a neighborhood within a 55 or higher DNL contour (or a community that has quality-assured noise measurement data that demonstrate 55 DNL impacts occurring outside the model contour of the aviation environmental design tool of the FAA) in which an airport operator or the Administrator determines, through the use of the framework and diagnostic tool developed by the National Academy of Sciences under section 3, that significant numbers of flight operations are conducted between 10:00 p.m. and 6:00 a.m. 8. Authorization of appropriations (a) In general There is authorized to be appropriated out of the Airport and Airway Trust Fund (established under section 9502 of the Internal Revenue Code of 1986) to carry out this Act— (1) a total