This aircraft is a descendant of General Aviation Manufacturing’s model GA-15 all metal, three-place, midwing monoplane observation aircraft built in 1935 at Dundalk, Maryland. General Aviation was a component firm of North American Aviation. In January 1936 the GA-15 was designated XO-47 by the US Army Air Corps (USAAC) and taken to Wright Field, (Dayton) Ohio for testing. In February 1937, the USAAC let an initial contract for 109 O-47As. North American Aviation closed the factory at Dundalk and opened a new factory at Inglewood, California. All 164 O-47As and all 74 O-47Bs were built there. Most of the aircraft (143) were assigned to National Guard units.

The O-47 is somewhat unique in that the USAAC never gave it a name. This particular O-47 is also a rare aircraft, being one of four known airframes in the world that are not wreckage. The National Air and Space Museum in Washington, D.C., has one example; another is held by the National Museum of the United States Air Force, Dayton, Ohio; one was last reported under restoration in Chino, California; and this example.

The crew included a pilot, second pilot, and gunner. The second pilot was rather busy, as he was also radio operator and cameraman. He could fold his seat and drop down into the observer’s station in the aircraft’s belly. The plane proved to be a reliable, stable platform for photography and was known for its rugged dependability.

The O-47 represents a time in US military aviation history when large observation planes were prevalent yet the advances in aircraft performance worldwide rapidly made their designs obsolete. They could not survive in the front-line environments of World War II. This was proven during massive war games in Louisiana and North and South Carolina in 1941. The O-47 and other observation aircraft were too large, too slow, too lightly armed, and lacked maneuverability. They were sitting ducks for fighters. In 1942 the designation “O” for Observation was dropped in favor of the designation “L” for Liaison. This reflected the new, lighter, more maneuverable and more useful liaison aircraft; the “grasshoppers.” 

O-47s did provide wartime service flying antisubmarine patrols along the US Atlantic coastline, being target tugs, serving in training and communication duties, and in general utility work. In January 1942, ten O-47s and their aircrews were placed aboard ships for transport to Singapore. They were to conduct coastal patrol and reconnaissance over the Malay Peninsula. Singapore fell before the aircraft arrived, and they were diverted to Australia where they spent the rest of the war. Other O-47s flew from bases in the Panama Canal Zone. In February 2002, the wreckage of one such O-47 was found in the mountains of western Panama. The aircraft last took flight on June 8, 1941 and vanished without a trace.

39-098 ended its flying service in the mid-1960’s in Tulsa, Oklahoma. It was one of five O-47s operated by General Aerial Surveys, Inc., for aerial surveys and aerial photography. Four of the O-47s were salvaged by the firm and sold for scrap. Mr. William A. “Bill” Dempsay of Rantoul, Kansas bought the fifth, 39-098, for $800 in 1965. He ferried the aircraft to his grass airstrip on the southern edge of Rantoul. Initially, Mr. Dempsay planned to convert the O-47 into an aerial sprayer but knowing he had a rather rare aircraft, did not carry through with this plan. He removed the plane’s control surfaces and occasionally turned over the engine, but the O-47 basically sat in one spot for the next 17 years.

Combat Air Museum acquired 39-098 on loan from Mr. Dempsay in May 1982. Museum volunteers loaded the plane onto a lowboy and began a 70-mile journey over secondary roads and through three counties from Rantoul to Topeka. Except for its wingtips and control surfaces, the O-47 was moved complete. It took some considerable planning, cooperation and teamwork to move a forty-two foot wide load over county roads twenty-four feet wide.

The aircraft, on display loan from Mr. William A. “Bill” Dempsay, owner, is for sale. Mr. Dempsay is currently working to make it airworthy for a ferry flight to another location where he can continue preparing the plane for its eventual sale.

Assignments:
Dec 29, 1939	Delivered to US Army Air Corps
January 1940	Missouri National Guard, Robertson Field, (St. Louis) Missouri
Circa 1941(?)	67th Observation Group, Esler Field, Camp Beauregard, (Alexandria) Louisiana
Circa 1942(?)	82nd Observation Squadron, Salinas Army Air Base, (Salinas) California
Sept 1945	Reconstruction Finance Corporation as surplus
1947–1965	Aero Exploration Co., then General Aerial Surveys, Inc., Tulsa, Oklahoma
1965–1982	D & D Aero Inc., Mr. Bill Dempsay, Rantoul, Kansas
1982	Placed on loan for exhibit to Combat Air Museum
TECHNICAL NOTES:
Manufacturer:	North American
Basic Role:	US Army Air Corps observation plane
Crew:	Three: pilot, second pilot/observer/photographer, gunner
Engines:	One 1,060 hp (791kW), nine-cylinder, Wright Cyclone R-1820, air-cooled, radial engine
Maximum speed:	227 mph (365km/hr)
Cruising Speed:	200 mph (322km/hr)
Range:	840 miles (1,352km)
Service Ceiling:	24,100 ft (7,346m)
Wingspan:	46 ft 4 in (14.12m)
Length:	33 ft 7 in (10.24m)
Height:	12 ft 7 in (3.84m)
Wing Area:	348.6 sq ft (32.39 sq m)
Weight (empty):	6,218 lbs (2,821kg); Gross: 8,045 lbs (3,649kg)
Armament:	One flexible, rearward firing .30 caliber machine gun; One fixed .30 caliber machine gun in the right wing US Army Air Corps
Serial number:	#39-098 Revised Serial Number 51-1011 FAA Reg. Number N73716