The GOES-R PLT Fly’s Eye GLM Simulator (FEGS) dataset consists of lightning flash, lightning pulse, and radiance data collected by the FEGS flown aboard a NASA ER-2 high-altitude aircraft during the GOES-R Post Launch Test (PLT) airborne science field campaign. The GOES-R PLT airborne science field campaign took place between March 21 and May 17, 2017 in support of the post-launch product validation of the Advanced Baseline Imager (ABI) and the Geostationary Lightning Mapper (GLM). These data files are available in ASCII format with browse imagery available in PNG format.