Maryland Air Guard Roots Steeped in Bomber Aircraft Published March 29, 2010 By Capt. Wayde Minami 175th Wing Public Affairs BALTIMORE -- Over the years, the Maryland Air Guard has flown an incredible variety of aircraft - at least 34 distinct models. And while Maryland Guardsmen have amassed an enviable combat record flying cargo and fighter aircraft in the counterinsurgencies in Iraq and Afghanistan, Maryland also has a legacy in bomber aircraft dating back to World War II. When the Maryland National Guard was mobilized in February 1941, its 104th Observation Squadron was equipped with O-46 and O-47 observation aircraft. Although both types of aircraft were armed with .30 caliber defensive machine guns, neither were intended to conduct ground attacks per se. Instead, their role was to report their observations to other units, which would conduct the actual attack. Following the air raid on Pearl Harbor, the Maryland National Guard began flying antisubmarine patrols along the Atlantic seaboard. But on Oct. 18, 1942, the 104th was inactivated and its members and aircraft transferred to the new 517th Bombardment Squadron, 377th Bombardment Group. The transition was largely transparent to unit members at the time, and the 517th continued its antisubmarine mission. In November, the 517th was redesignated the 12th Antisubmarine Squadron as part of a major reorganization of U.S. Army Air Forces Antisubmarine Command. The 12th, along with the rest of the 377th Bombardment Group, now fell under the 25th Antisubmarine Wing. Ten days later the 377th Bombardment Group was deactivated and the 12th began reporting directly to the wing. Soon after the change in unit came a change in aircraft. The unit continued to fly the O-46 and O-47 for a period, but then converted to the Douglas B-18B Bolo, a maritime patrol version of the B-18A medium bomber. The twin-engine B-18, which was based on the DC-2 commercial airliner, had originally been developed to replace the B-10 as the standard bomber of the Army Air Corps. Equipped with three .30 caliber defensive machine guns and capable of carrying a bomb load of 4,500 lbs., it had been selected over more advanced designs because of its lower cost. The B-18 remained the Air Corps' primary bomber into 1941, but by 1942 had been relegated to second-line status as improved bombers like the B-17 replaced it. B-18s continued to serve as transports, and 122 were modified to the B-18B configuration, wherein the bombardier's glassed-in nose was replaced by a search radar. Some were also equipped with tail-mounted magnetic anomaly detectors for locating submerged U-boats. In 1943, the B-18 was superseded by the B-24 Liberator in the antisubmarine role, although a number of antisubmarine units, including the 12th, were equipped with B-25 Mitchells as an interim measure until sufficient B-24s were available. But in September of that year, the declining threat posed by German U-boats resulted in the 12th being transferred to Blythe Army Airfield, Calif., at which time most of the remaining Maryland Guardsmen were sent elsewhere as individual replacements. According to the Army Air Force's combat chronology, the 12th had begun receiving B-24s by the time it moved from Langley to Blythe, but it is unclear to what extent the unit actually flew that aircraft operationally. Although the 12th Antisubmarine Squadron, having been organized after the Guard had been called into federal service, was technically never a National Guard unit, its roots are clearly with the members of the Maryland National Guard who manned it from its creation in 1942. And while the B-18 is a largely forgotten footnote in combat aviation history, it has the distinction of being the first true combat aircraft to be flown by members of the Maryland Guard.