his own men while being chased by troops under General Pershing. (see: Pershing's diary of the expedition.) 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 19th, 1916 onwards. This was 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 could handle. They simply didn't have enough power to fly over the mountains of northern Mexico. One rain storm poured nearly a foot of water into the cockpit of Cpt. Foulois' craft and flooded out his engine. He successfully managed to land his plane without power. Every landing in Mexico was carried out in hostile territory. Many pilots found themselves cut off from friendly lines with little hope of rescue The squadron flew 540 missions in Mexico – averaging 36 miles (58 km) per mission. After six weeks, they were done. Their airplanes were worn out, and two had crashed. Four others needed parts and were grounded. Crew members and pilots had blisters from carving new propellers out of logs. On April 20th, 1916, the Army ordered the squadron back to Columbus, N.M. Their only real military success was finding a lost and thirsty cavalry column. The 1st Aero Squadron received new airplanes, but these were hurriedly packed by the factory, were all missing parts and required significant modifications. The squadron did not again take to the field until they deployed to France as part of the American Expeditionary Force in World War I. Today, the 1st Reconnaissance Squadron of the U.S. Air Force at Beale AFB traces its unit heritage to the 1st Aero Squadron. Henry Post Army Airfield In August 1917, Capt. H.R. Eyrich surveyed a new airfield location at Fort Sill and established Henry Post Army Airfield (named after 2nd Lt. Henry Post who was killed in a plane crash in San Diego in 1914). The field occupies a small plateau about a mile south of the main post cantonment area. Construction immediately began on wooden hangars, offices and officer housing. As the U.S. entered World War I, the airfield was used to train aerial