FSX/P3D – C-45H N8640E Grimes Flying Laboratory. This file updates and replaces the file B18DC09. The Beechcraft Model 18 aircraft is the most modified U.S.-certified aircraft design, with over 200 Federal Aviation Administration (FAA) approved Supplemental Type Certificates (STC’s) on record for the aircraft. The C-45H N8640E Grimes Flying Laboratory is a flying aircraft lighting demonstrator which has been restored by the Grimes Flying Lab Foundation and operates out of Grimes Field in Urbana, OH. This model was produced, at the request of the foundation and with their data support, by Dave Carroll.