Characteristics of polycyclic aromatic hydrocarbon (PAH) emissions from a UH-1H helicopter engine and its impact on the ambient environment

The objective of this study is to characterize the emissions of polycyclic aromatic hydrocarbons (PAHs) from a UH-1H helicopter turboshaft engine and its impact on the ambient environment. Five power settings of the ground idle (GI), fly idle (FI), beed band check (BBC), inlet guide vane (IGV), and take off (TO) were selected and samples were collected from the exhaust by using an isokinetic sampling system. Twenty-two PAH compounds were analyzed by gas chromatograph (GC)/MS. We found the mean total PAH concentration in the exhaust of the UH-1H engine (843 μg m−3) is 1.05−51.7 times in magnitude higher than those of the heavy-duty diesel (HDD) engine, motor vehicle engine, and F101 aircraft engine. Two- and three-ringed PAHs account for 97.5% of total PAH emissions from the UH-1H engine. The mean total PAH and total BaPeq emission factors for the UH-1H engine (63.4 and 0.309 mg L−1•fuel) is 1.65−23.4 and 1.30−7.54 times in magnitude higher than those for the motor vehicle engine, HDD engine, and F101 aircraft engine. The total emission level of the single PAH compound, BaP, for the UH-1H engine (ELBaP) during one landing and take off (LTO) cycle (2.19 mg LTO−1) was higher than the European Commission standard (1.24 mg LTO−1) suggesting that appropriate measures should be taken to reduce PAH emissions from UH-1H engines in the future.