The Lockheed JO was the US Navy’s designation for the Lockheed 12 Electra Junior, a small twin engine transport aircraft.
The standard Lockheed 12 Electra Junior was a smaller version of the Lockheed 10 Electra, with the same basic layout. It had a low mounted tapered cantilevered wing, with twin Pratt & Whitney Wasp Jr engines, a crew of two and space for six passengers (down from ten on the Electra).
The Navy’s first aircraft was a single seven seat JO-1, delivered on 9 August 1937 and used by the US Naval Attaché in Brazil.
This was followed by five JO-2s, powered by the Pratt & Whitney R-985-48 engine. They had six seats, and were used as command and staff transports - four by the Navy and one by the Marine Corps.
The final Naval Electra Junior was the XJO-3, which was the first of the type to feature a fixed non-retractable tricycle undercarriage. This aircraft was used for deck landing trials on the USS Lexington in August 1939 to test out the practicality of using the tricycle undercarriage on aircraft carriers.
One Electra Jr was impressed during the Second World War, but as the R3O-2 and not a version of the JO.
Standard Electra Jr
Engines: Two Pratt & Whitney Junior SB
Power: 450hp at take off, 400hp at sea level
Wing span: 49ft 6in
Length: 36ft 4in
Height: 9ft 9in
Empty weight: 5,765lb
Loaded weight: 8,400lb
Maximum weight: 8,650lb
Maximum speed: 225mph at 5,000ft
Cruising speed: 213mph
Service ceiling: 22,900ft
Normal range: 800 miles
Lockheed Aircraft Since 1913, René J Francillon