The squadron returned to Columbus on 22 April for new aircraft, where it expanded to a roster of 16 pilots and 122 enlisted men. It flew liaison missions for Pershing's force using detachments in Mexico until 15 August 1916. The 1st Aero Squadron flew a total of 540 liaison and aerial reconnaissance missions, traveling with a flight time of 345 hours 43 minutes. No observations were made of hostile troops but the squadron performed invaluable services maintaining communications between Pershing's headquarters and ground units deep inside Mexico. During this expedition, a solid red star on the rudder became the first national insignia for United States military aircraft.