A small detachment with S.C. 31, a Martin T tractor airplane, returned from San Diego to Texas for the fourth time in five years in April 1915, led by 1st Lt. Thomas D. Milling and 2d Lt. Byron Q. Jones, as the Army massed around Brownsville in response to civil war between the forces of Pancho Villa and the Carranza government. On 20 April, Milling and Jones became the first American military airmen to come under fire from a hostile force.