The 1st Aero Squadron was part of that army. They transferred to Casas Grandes in Mexico and began duties flying reconnaissance, delivering mail and dispatches and transporting senior officers, all marked with a red five-pointed star on their rudders for their American national insignia from March 19, 1916 onwards, as the earliest-known instance of a "national insignia" of any sort used on American military aircraft. The simple sorts of military-related tasks the early Curtiss biplanes were being used for, were more than their airframes (designed for training, not combat) could handle. They simply didn't have enough power to fly over the mountains of northern Mexico. One rain storm dumped nearly a foot of water into the cockpit of Foulois' craft and flooded out his engine. He successfully managed to land his plane without power. Additionally, every landing in Mexico was carried out in hostile territory. Many pilots found themselves cut off from friendly lines with little more than their wits to rescue them from hostile Mexicans and Mexican officials.