This dataset includes Level 1B (L1B) and Level 2 (L2) data products from the MODIS/ASTER Airborne Simulator (MASTER) instrument. The spectral data were collected as part of the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) program during 21 flights aboard a NASA DC-8 aircraft over the central and western U.S. from 2019-07-22 to 2019-09-03. The purpose of these flights was to measure emissions and to characterize the aerosols in the smoke plume above and downwind of the fire, and to determine the overall spatial extent of wildfires and prescribed fires. Data products include L1B georeferenced multispectral imagery of calibrated radiance in 50 bands covering wavelengths of 0.460 to 12.879 micrometers at approximately 20-meter spatial resolution. Derived L2 data products are emissivity in 5 bands in thermal infrared range (8.58 to 12.13 micrometers) and land surface temperature. The L1B file format is HDF-4, and L2 products are provided in ENVI and KMZ formats. In addition, the dataset includes the flight path, spectral band information, instrument configuration, ancillary notes, and summary information for each flight, and browse images derived from each L1B data file.