Engine Instrument Systems (1) Powerplant instrument range markings show whether the current state of powerplant operation is normal, acceptable for a limited time, or unauthorized. (2) Powerplant instrument range markings are based on installed engine operating limits which may not exceed (but are not necessarily equal to) those limits shown on the engine Type Certificate Data Sheet. Regarding the above statements, a. both No. 1 and No. 2 are true. b. neither No. 1 nor No. 2 is true. c. only No. 1 is true.