"(B) Limitations. The
Secretary shall not authorize the conversion of any of following
facilities or functions of the air traffic control system, as defined in
section 40102, to a private entity or a public entity other than the
United States Government:
"(i) A facility controlled by the Federal Aviation Administration.
"(ii) Operations performed, on the date of enactment of this subparagraph,
by Federal employees at a facility controlled by the Federal Aviation
Administration.
"(iii) Maintenance, engineering, or oversight functions performed, on or
after the date of enactment of this subparagraph, at a facility controlled
by the Federal Aviation Administration.
"(C) Applicability of limitations.--
"(i) Contract tower
program.-- Subparagraphs (B)(i) and (B)(ii) shall not apply to a
Federal Aviation Administration airport traffic control tower operated
under the contract tower program on the date of enactment of this
subparagraph.
(ii) Existing maintenance and engineering agreements.--
Subparagraphs (B)(iii) shall not apply to the renewal or replacement of a
maintenance or engineering agreement in effect on the date of enactment of
this subparagraph.".