Sec. 21.473 - Airworthiness
certificates other than experimental.
For each amendment made to a standard airworthiness certificate under this subpart, the DAS shall follow the procedure manual prescribed in §21.441 and shall, before making that amendment --
(a) Complete each flight test necessary to meet the applicable airworthiness requirements of this chapter;
(b) Find that each applicable airworthiness requirement of this chapter is met; and
(c) Find that the aircraft is in condition for safe operation.