Amendment of the Type Certification Procedures for Changes in Helicopter Type Design to Attach or Remove External Equipment

This final rule amends the existing helicopter noise certification procedures with respect to certain changes in type designs. The applicability of the noise certification procedures is amended to exclude those changes in type design that involve the attachment or removal of external equipment, floats and skis, and certain airframe and operational changes made to accommodate such changes in type design (acoustical change requirements). Also excluded from the applicability of the acoustical change requirements are helicopter flight operations with doors and/or windows removed or in an open position. This amendment also makes U.S. helicopter noise certification regulations more consistent with the International Civil Aviation Organization (ICAO) standards.