... of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures;’’ Final Rule, 47 FR 58462, December 30, 1982. 71U.S.EPA, ‘‘Control of Air Pollution from Aircraft ... Finding for Commercial and Noncommercial Turbofan and Turbojet Aircraft Emissions, ’’ memorandum from John Mueller, Assessment and Standards Division, Office of Transportation and Air Quality, ... Exemptions from the Tier 6 Production Cutoff for the Proposed Rulemaking on Aircraft Engine Emission Standards, ’’ memorandum from Richard S. Wilcox, Assessment and Standards Division, Office of Air...