This document is a detailed flight log and technical record maintained by Lieutenant Benjamin D. Foulois during the early testing and development of the U.S. Army's first airplane, Signal Corps No. 1, at Fort Sam Houston, Texas, between 1910 and 1911. The logbook meticulously records daily flight data including start and finish times, flight durations, maximum altitudes, glide distances, fuel consumption, and prevailing wind conditions, along with specific propeller performance test data such as full-advance readings of up to 1454 RPM and full-retard values around 1100 RPM. It documents numerous mechanical modifications and troubleshooting efforts—from repairs to engine components, replacement of broken bed plates and truss braces, and the addition of a pioneering tricycle landing gear with small wheels and shock absorbers—to improve takeoff and landing performance. The record also details field experiments at the target range near Leon Springs, Texas, and highlights the contributions of enlisted personnel including Private Glenn R. Madole, Sergeant Stephen J. Idzorek, Sergeant Herbert Marcus, Corporal Vernon L. Burge, and civilian mechanic Oliver G. Simmons, all of whom played key roles in advancing early military aviation techniques.