CFR > Title 14 - Aeronautics and Space > CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION > SUBCHAPTER C—AIRCRAFT (parts 21 to 50) > PART 34—FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES > SUBPART D—Exhaust Emissions (In-use Aircraft Gas Turbine Engines) (§34.30 to §34.31) > 34.31—Standards for exhaust emissions.

34.31—Standards for exhaust emissions.

(a) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of Class T8, beginning February 1, 1974, shall not exceed a smoke number (SN) of 30.
(b) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of Class TF and of rated output of 129 kilonewtons (29,000 pounds) thrust or greater, beginning January l, 1976, shall not exceed

Code of Federal Regulations

SN=83.6(rO)−0.274 (rO is in kilonewtons).
(c) The standards set forth in paragraphs (a) and (b) of this section refer to exhaust smoke emissions emitted during operations of the engine as specified in the applicable section of subpart H of this part, and measured and calculated in accordance with the procedure set forth in this subpart.