Experimental study of particle deposition in the environmental control systems of commercial airliners

Serious air pollution and low on-time performance of commercial flights in China could result in more particles being deposited in the environmental control systems (ECS) of the commercial airliners and ground air-conditioning carts (GAC). The particle deposited in the ECS and GAC could cause performance issues of the airplanes and GAC. In addition, particles penetrated to the aircraft cabin could cause adverse health impact on the passengers and crew. This investigation measured the PM_2.5 particle concentrations and the quantities of particles of different sizes at the inlet and outlet of the GAC and ECS in an MD-82 airplane parked next to Tianjin Airport under different air quality levels. The results showed that the deposition rate of the PM_2.5 mass in the GAC and ECS was 40-50%, with most (30-40%) of the deposition occurring in the ECS. For particles with a diameter of 5 μm or larger, the deposition rate was greater than 90%. For particles with a diameter of 0.5 μm or less, the deposition rate was less than 25% so they entered into the aircraft cabin. In addition, particle mass and number concentration was measured on commercial flights. The results indicated that particle concentrations were high compared with that during the cruising when the airplanes were on the ground at the Chinese airports where ambient particle concentrations were also high.