In preparation for airborne sampling of insoluble particles in atmospheric chemistry field experiments this project in designed to develop insoluble particle collectors with the highest possible efficiency for particles in the diameter range 0.1 - 2.62 micrometer and for particles larger than 5 micrometer. To overcome the fact that atmospheric particle concentrations are relatively low and to minimize flight time, particles will be collected on large 90 mm diameter Nuclepore filters. The system and its placement and orientation on the aircraft will be designed in such a way as to minimize loss of particles in the intake. This will compare the extent to which airborne particle recovery is representative of particles collected on stationary, high elevation platforms.