Photo: Manned OL-5 cockpit with machine gun.

“CG 1”

The Coast Guard’s first aircraft

The first aircraft built for the United States Coast Guard was a Loening OL-5 delivered to the service in October 1926.

Photo: Loening OL-5 sea plane.

Credit: U.S. Coast Guard

Rare photograph of the first Loening OL-5 purchased by the Coast Guard. The original was signed by manufacturer Grover Loening.

A decade earlier, Coast Guard aviation was established by an act of Congress. It authorized the Treasury Department to establish 10 Coast Guard air stations along U.S. coasts. Coast Guard personnel were sent to Pensacola Naval Air Station for flight and maintenance training. However, with the advent of World War I, the Coast Guard became part of the U.S. Navy, and no funds were ever appropriated for this program. After the war, a project was undertaken to illustrate the value of aircraft in the saving of human life. The Navy provided a decommissioned naval air station and several loaned aircraft for the project. The results were highly favorable but there was no money available for operations and the program ended within a year.

This false start could have been the demise of Coast Guard aviation, but it was not. Prohibition of the manufacture, importing, transportation and selling of alcoholic beverages had become the law of the land in January 1920. Enforcement of the law fell to the Treasury Department and the Coast Guard was tasked with interdicting maritime smuggling. In the early years of Prohibition, maritime smuggling was slow, but it grew exponentially. What became known as the “Rum War” had begun.

In 1921, aviator Lt. Cmdr. Carl Christian von Paulsen became commanding officer of Section Base #7 located at Gloucester, Massachusetts. The Gloucester area of responsibility included the coastal waters, harbors and bays from Marblehead, Massachusetts, to Portland, Maine. Von Paulsen approached Coast Guard leadership with the idea of using aircraft to search and locate “blacks,” large vessels so named because they ran at night with no running lights, and small rum running boats making a run for shore. Von Paulsen argued that aircraft could search over a much larger area in less time than a surface vessel and convinced the Coast Guard commandant to approve the concept.

Photo: Lieutenant Commander C.C. von Paulsen, Ensign Leonard Melka, and dog Brutus pose in front of a Vought UO01 amphibious plane.

Credit: Photo courtesy of the von Paulsen family

Lt. Cmdr. C.C. von Paulsen, his dog “Brutus” and co-pilot ENS Leonard Melka, pose in front of a loaned Navy Vought UO-1 amphibian flown out of Squantum Naval Air Station in Quincy, Massachusetts.

In 1925, the Coast Guard borrowed an aircraft from the Navy for proof of concept. In May, Von Paulsen and another veteran aviator flew out of Squantum Naval Air Station in Quincy, Massachusetts. By July 11, the borrowed Navy aircraft performed the first aerial law enforcement assist. Over the next several months, Coast Guard aircraft flew thousands of miles locating smugglers and directing patrol boats to apprehend them. The experience obtained from operating this aircraft demonstrated to service leadership the advantages of using aircraft in interdiction patrols and the importance of procuring aircraft and air stations.

Photo: Charles Thrun stands on the center float of an OL-5.

Credit: Smithsonian Institution

Distinguished Coast Guard pilot Charles Thrun standing on an OL-5 float in an early aviator suit. Notice the landing gear folded into the float behind him.

In 1926, Congress appropriated $162,000 to purchase five Coast Guard aircraft designed specifically for the service’s needs. The OL-5 was a high-performance amphibian aircraft with a large center float faired into the fuselage and stabilizing floats underneath each lower wing. The wheels were designed to fold up when operating on the water. The amphibian’s wingspan was 45 feet, and it was 35 feet in length. The landing gear was retractable by use of a hand crank in the cockpit, and the plane was equipped with a tailskid for operations on land. It had a tandem open cockpit for a crew of two and could carry one passenger. The OL-5 had a 400-horsepower engine, a 450-mile range and a top speed of 120 mph. The service equipped the OL-5s with radios capable of voice communication within 150 miles. In addition, the OL-5s were each armed with a machine gun and occasionally made use of them in interdiction cases.

Photo: Manned OL-5 cockpit with machine gun.

Credit: U.S. Coast Guard

Close-up of an OL-5 cockpit with an air-cooled machine gun mounted aft for aerial use of force and law enforcement interdiction.

In the summer of 1926, the Coast Guard began building an air station at Ten Pound Island in Gloucester Harbor. The service had to blast and level the granite island and poured concrete for a large steel hangar. On October 14 the first OL-5 arrived at Ten Pound Island with the second OL-5 assigned to a new air station opened at Cape May, New Jersey. The Third OL-5 arrived at Ten Pound Island in early November.

Photo: Aerial view of amphibian airbase.

Credit: U.S. Coast Guard

Aerial view of the amphibian airbase at Ten Pound Island, Gloucester Harbor, after several years in service.

Interdicting illegal liquor smuggling remained the air station’s primary mission. Daily patrols were flown in aircraft not only capable of radio communication with surface units and shore stations but capable of obtaining the bearings for a rum runner’s radio messages. As the mother ships of Rum Row moved farther offshore and the search expanded, the best use of aircraft was locating the blacks. The aircraft would notify Coast Guard cutters of the smuggler’s location and then circle over the black until a cutter arrived to apprehend the vessel.

The combination of aircraft, cutters, picket boats, special-purpose interceptor craft, and radio technology helped the Coast Guard win the Rum War.

Editor’s note: The author’s narrative “The Beginning, Demise and Resurrection of Coast Guard Aviation” may be found at https://cgaviationhistory.org/historical-narrative/cg-aviation-beginning-demise-resurrection/

National Coast Guard Museum insider tip: Visitors to the National Coast Guard Museum will learn about the incredible story of how the Coast Guard took to the air in the Development of Aviation Rescue exhibit on Deck 2.