Since launch of the Suomi NPP (SNPP) satellite in late 2011, two airborne field campaigns have been conducted with a primary focus on SNPP instrument and data product calibration / validation: 1) mid-latitude flights based out of Palmdale, CA during May 2013 (SNPP-1), and 2) flights over Greenland during March 2015 while based out of Keflavik, Iceland (SNPP-2). In addition to under-flying SNPP, aircraft flight profiles were defined to also obtain coincident observations with the NASA A-train (i.e. AQUA), MetOP-A, and MetOP-B advanced sounder satellites (i.e. AIRS, IASI, and CrIS), along with radiosonde and ground truth sites. The NASA LaRC National Airborne Sounder Testbed-Interferometer (NAST-I) was one of the key payload sensors aboard the ER-2 aircraft during these campaigns. This presentation summarizes the SNPP field campaigns and shows sample inter-comparisons results involving NAST-I and other measurement assets.