EXTENSION OF AIRPORT IMPROVEMENT PROGRAM.

SEC. 4. EXTENSION OF AIRPORT IMPROVEMENT PROGRAM. (a) Authorization of Appropriations.— (1) In general.—Section 48103(9) of title 49, United States Code, is amended to read as follows: “(9) $1,344,535,519 for the period beginning on October 1, 2011, and ending on February 17, 2012.” . (2) Obligation of amounts.—Subject to limitations specified in advance in appropriation Acts, sums made available for a portion of fiscal year 2012 pursuant to the amendment made by paragraph (1) may be obligated at any time through September 30, 2012, and shall remain available until expended. (b) Project Grant Authority.—Section 47104(c) of such title is amended by striking “January 31, 2012,” and inserting “February 17, 2012,”.