FAA Federal Aviation Regulations (FARS, 14 CFR)

(a) The aircraft class ratings to be placed on flight engineer certificates are --

(1) Reciprocating engine powered;

(2) Turbopropeller powered; and

(3) Turbojet powered.

(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.