Lost Broncos from Burbank and El Segundo

Much has been written about the Light Armed Reconnaissance Aircraft (LARA) competition of the mid-1960s for an aircraft designed to carry out counter-insurgency (COIN) operations, which produced the North American OV-10 Bronco (which won the LARA competition) and the rival, prototype-only Convair Model 48 Charger. However, the Model 48 Charger, despite being manufactured in my home state, was not the only LARA design conceived in southern California. Two additional companies based in southern California put out design bids for the LARA competition, one emanating from Burbank and another coming from the design offices of the El Segundo Division of Douglas. 

Company artwork of the Douglas D-855

Following the issuance of the tri-service LARA requirement in late 1963, nine companies submitted bids for the LARA competition by March 1964, of which three (Convair San Diego, Douglas El Segundo, and Lockheed) were based in southern California. The Douglas proposal, designated D-855, took the form of a high-wing airplane with a T-tail empennage, a rear loading door, a crew of two seated in tandem, a length of 35 feet (10.67 meters) long, and a wingspan of 29 feet (8.83 meters). The D-855 would carry six fully-equipped troops or a 6,000 lb (2,721 kg) payload in the fuselage, and various weapons loads (e.g. folding fin unguided air-to-ground rockets and bombs) were carried below five hardpoints, one situated below the fuselage centerline, two below the wing roots, and two positioned just inboard of the wingtips. Top speed of the D-855 was to be 230 mph (370 km/h), and power would be provided by either two United Aircraft of Canada T74 or Garret AiResearch T76 turboprops. The El Segundo Division of Douglas informally referred to the D-855 as the "Skyraider II", a testament to its rich experience with attack aircraft design.

Full-scale mockup of the Lockheed CL-760 with external weapons carried onboard or individual displayed on the ground. 

The Lockheed submission for the LARA competition, the CL-760, shared the high-wing layout and the  tandem seating arrangement for the two crewmembers with the D-855, but it had a conventional tail empennage whose horizontal stabilizers formed a triangular planform. It measured 40 feet 3.5 in (12.28 meters) long with a wingspan of 30 feet (9.14 meters), an empty weight of 5,106 lb (2,316 kg), a gross weight of 9,270 lb (4,205 kg), and a top speed of 325 mph (523 km/h). Accommodations were provided for either eight fully equipped troops or six paratroopers in the cargo hold, and power was to come from two Garrett T76 turboprops, while the retractable main landing gear and four 7.62 mm machine guns would be housed in two fuselage blisters. The CL-760 had four racks below the wingtips (two below each wingtip) and a fifth pylon below the fuselage centerline for carrying various weapons, including folding-fin unguided air-to-ground rockets, air-to-surface missiles, and bombs. When configured for reconnaissance, the CL-760 itself would carry advanced cameras and sensors to allow it to loiter over positions and movements of enemy insurgents in various terrains such as dense forests and open fields at low altitudes. 

In August 1964, the US Navy declared North American NA-300 was declared the winner of the LARA competition (although the US Air Force and US Marine Corps had preferred the rival Convair Model 48 design, of which a prototype was under construction at the time of the announcement of the outcome of the LARA competition), receiving the designation OV-10 and the official name Bronco. Because the Douglas El Segundo Division and Lockheed lost the LARA competition to the NA-300, the Model 48  would be the only competing LARA design from southern California to be built and flown, making its first flight on November 25, 1964, eight months before the OV-10 took to the skies.

References:

Francillon, R., 1987. Lockheed Aircraft Since 1913. Annapolis, MD: Naval Institute Press. 

Ginter, S., Auten, H., Knebel, J, and Fink, J., 1997. Convair Model 48 Charger (Naval Fighters No. 39). Simi Valley, CA: Ginter Books.