10/31/2009. Remarks by Johan Visschedijk: "After the sale of the Lockheed Aircraft Company to the Detroit Aircraft Company July 1929, Allan and Malcolm Loughead (the original spelling of their surname) resigned and established the Loughead Brothers Aircraft Corporation. Allan Loughead designed a five-seat monoplane (essential a Lockheed 5 Vega) that was to be powered by a Wright J-6 Whirlwind seven-cylinder radial, eventually two 125 hp Menasco C-4 Pirate four-cylinder air-cooled in-line engines were mounted side-by-side.

Designated Duo-4, named Olympic and registered X962Y, the aircraft was first flown by test pilot Frank Clarke in 1930. The aircraft was slightly damaged after a nose-over upon landing at Muroc, California, on March 18, 1931, due to financial problems the aircraft was not repaired. In 1934 the company failed.

Subsequently Allan Loughead formed the Alcor Aircraft Corporation (Alcor stood for Allan Loughead Corporation) and repaired the damaged Duo-4. Re-engined with two 230 hp Menasco B-6S Buccaneer six-cylinder air-cooled in-line engines the aircraft was redesignated Duo-6. It was flown in 1934, a year later it crashed again and was not repaired."

Span: 42 ft 0 in (12.80m)
Length: 28 ft 5 in (8.66 m)
Height: 9 ft 6 in (2.90 m)
Wing area: 282 sq.ft (26.2 sq.m)
Weight empty: 2,885 lb (1,309 kg)
Useful load: 2,205 lb (1,000 kg)
Payload: 1,300 lb (590 kg)
Gross weight: 5,090 lb (2,309 kg)
Max speed: 190 mph (306 kmh)
Cruise speed: 160 mph (257 kmh)
Landing speed: 57 mph (92 kmh)
Service ceiling: 18,500 ft (914 m)
Climb: 1,400 ft (427 m)/min
Range: 660 mls (1,062 km)