Propellers (1) A mechanic certificate with a powerplant rating authorizes the holder to repair deep scars, nicks, and dents on aluminum propeller blades. (2) A mechanic certificate with a powerplant rating authorizes the holder to perform minor straightening of steel propeller blades. Regarding the above statements, a. only No. 1 is true. b. both No. 1 and No. 2 are true. c. neither No. 1 nor No. 2 is true.