Section 63.33 - Aircraft ratings(a) The aircraft class ratings to be placed on flight engineer certificates are- (1) Reciprocating engine powered;(2) Turbopropeller powered; and(b) To be eligible for an additional aircraft class rating after his flight engineer certificate with a class rating is issued to him, an applicant must pass the written test that is appropriate to the class of airplane for which an additional rating is sought, and- (1) Pass the flight test for that class of aircraft; or(2) Satisfactorily complete an approved flight engineer training program that is appropriate to the additional class rating sought.