Rolls Royce Corporation

The word "turbine" is used throughout the NPRM and request that this be better defined as (turbofan or turbojet), which we believe the NPRM is targeting. A better defined interpretation of the word "turbine" will avoid confusion with including the propeller driven turboprop engines. We suggest the wording in section 21.35 be changed to: “21.35 Flight tests (b) (2) For aircraft to be certificated under this subchapter, except gliders and except propeller driven airplanes of 6,000lbs. or less maximum certificated weight that are to be certificated under part 23 of this chapter, to determine whether there is reasonable assurance that the aircraft, its components, and it equipment are reliable and function properly. “