(b) Noise limits. It must be shown, in accordance with the provisions of this part in effect on October 13, 1977, that the noise levels of the airplane are reduced to the lowest levels that are economically reasonable, technologically practicable, and appropriate for the Concorde type design.
[Amdt. 36–10, 43 FR 28420, June 29, 1978, as amended by Amdt. 36–54, 67 FR 45212, July 8, 2002]