49 USC 47153 - Waiving and adding terms

(a) General Authority.— 

(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) Waivers and Inclusion of Additional Terms on Request.— 
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 section 47152 of this title 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) Public Notice Before Waiver.— 
Notwithstanding subsections (a) and (b), before the Secretary may waive any term imposed under this section that an interest in land be used for an aeronautical purpose, the Secretary must provide notice to the public not less than 30 days before waiving such term.