The C-130's second test flight was to an area north of Cheyenne, WY, in strong northwesterly airflow. The aircraft climbed through a shallow Cu/Sr-Cu layer at about 13000 ft, and leveled out at 18000 ft. At this level the C-130 was between the lover cloud deck and a higher-level cirrus deck. A set of staged, speed maneuvers was made on a reverse-heading track, followed by a roller-coaster and a set of yaw maneuvers. All of these were designed to test the newly-installed pitot-static system. This part also served as a means of extended sampling of upper-level aerosol particles and as a set of observations for making corrections to the new DRI hot-wire T-probes. SABL was operated looking upwards at the upper-level cirrus deck for most of the time. One interesting observation was very low particle concentrations for most of these flight legs. CN concentrations as low as 2 per cc were observed from the C-130 CN counter, from the CVI and from the CSU ice nuclei system. When subsequently flying in very thin wave clouds off the main track, particle concentrations about 40 times higher were observed. Two wave-cloud flight legs were conducted at 19000 ft and 19500 ft at temperatures of about -12 C. CPI images showed only spherical particles, indicating a water cloud. After this the C-130 descended to the lower Cu/Sr-Cu deck, and *surprisingly* the same very clean air was found below the wave clouds. It is not clear if there was new particle production in the wave clouds or if some other explanation must be sought. Three flight legs were done in the lower Cu/Sr-Cu deck. The first was done at 15000 ft near cloud top, and this was followed by two legs at 14000 ft. The purpose of the lower two flight decks was to examine if the CSU ice nuclei system gave different results using the normal inlet or the CVI inlet. Finally two reverse-heading legs were done below cloud base in the boundary-layer air, followed by a transit back to JeffCo in very turbulent conditions. - Jorgen