(a) Applicability. This section applies to civil supersonic
airplanes that have not been shown to comply with the Stage 2 noise limits
of part 36 in effect on October 13, 1977, using applicable trade-off
provisions, and that are operated in the United States, after July 31,
(b) Airport use. Except in an emergency, the following apply to
each person who operates a civil supersonic airplane to or from an airport
in the United States:
(1) Regardless of whether a type design change approval is applied for
under part 21 of this chapter, no person may land or take off an airplane
covered by this section for which the type design is changed, after July
31, 1978, in a manner constituting an "acoustical change" under §21.93
unless the acoustical change requirements of part 36 are complied with.
(2) No flight may be scheduled, or otherwise planned, for takeoff or
landing after 10 p.m. and before 7 a.m. local time.