((a)) ** .—**

((1)) The Secretary of Transportation may waive, without charge, a term of a conveyance of an interest in property under this subchapter if the Secretary decides that—

((A)) the property no longer serves the purpose for which it was conveyed; or

((B)) the waiver will not prevent carrying out the purpose for which the conveyance was made and is necessary to advance the civil aviation interests of the United States.

((2)) The Secretary of Transportation shall waive a term under paragraph (1) of this subsection on terms the Secretary considers necessary to protect or advance the civil aviation interests of the United States.

((b)) ** .—** On request of the Secretary of Transportation or the Secretary of a military department, a department, agency, or instrumentality of the executive branch of the United States Government or a wholly owned Government corporation may waive a term required by or add another term if the appropriate Secretary decides it is necessary to protect or advance the interests of the United States in civil aviation or for national defense.

((c)) ** .—** Notwithstanding subsections (a) and (b), the Secretary may not waive any term under this section that an interest in land be used for an aeronautical purpose unless—

((1)) the Secretary provides public notice not less than 30 days before the issuance of a waiver; and

((2)) the Secretary determines that such waiver—

((A)) will not significantly impair the aeronautical purpose of an airport;

((B)) will not result in the permanent closure of an airport (unless the Secretary determines that the waiver will directly facilitate the construction of a replacement airport); or

((C)) is necessary to protect or advance the civil aviation interests of the United States.