Pay, Army. Executive order [promulgating regulations for carrying into effect provisions of sec. 20 of act approved June 10, 1922, as amended by sec. 6 of act of July 2, 1926, relative to increased pay for personnel of Army, Navy, Marine Corps, Coast Guard, and National Guard when they are required to participate regularly and frequently in aerial flights, and for allowances for traveling expenses incident thereto, effective for National Guard, Apr. 1, 1927, and for all other services, July 1, 1927].