Emission and Formation of Aircraft Engine Oil Ultrafine Particles

Civil aviation gas turbine engines emit ultrafine particles (UFPs, diameter < 100 nm). UFPs degrade air quality because they efficiently transport their chemical content, including engine oil, into the body. Yet, little is known about how and when oil containing UFPs are formed. Results here describe the thrust and flight phase-dependent oil emission and reveal the particle size-dependent transfer of vaporized oil to UFPs with molecular level resolution. All six engines studied emitted oil containing UFPs. Lower volatility oil molecules are enriched on particles 2 h, 95% of oil emission is expected to occur at cruise altitude, highlighting the unknown effects of oil emission in the upper atmosphere.