Both the civilian and military Skymasters were low-cost twin-engine piston-powered aircraft, with one engine in the nose of the aircraft and a second in the rear of the fuselage. The
push-pull configuration provided centerline thrust, allowing simpler operation than the low-wing mounting of most twin-engine light aircraft, and allowed a high wing to be used, providing clear observation below and behind the aircraft.
Modifications made for the military configuration included fore-and-aft seating for a pilot and observer, instead of the six seats of the civilian version; installation of view panels in the doors (for improved ground observation); installation of flame-retardant foam in the wing-mounted fuel tanks (slightly increasing weight, and reducing maximum fuel capacity by 3%); installation of military, rather than civilian, communication and navigation equipment and antennas; removal of
propeller spinners; increased gross weight (5,400 lb vs. 4,400 lb in civilian version), with component strengthening as required to support the increase; and removal of interior upholstery.
The first O-2 flew in January 1967, and the plane went into production shortly thereafter. Performance (especially at cruising altitudes) was degraded due to the added antennas and significant weight increase, but was considered sufficient for the anticipated low-level operation.
The USAF took delivery of the O-2 Skymaster in March 1967 and the O-2A also entered the U.S. Army's inventory during 1967, from USAF stock. By 1970, a total of 532 O-2s had been built, in two variants, for the USAF.
While it was intended that the Skymaster be replaced in the FAC mission by the
OV-10 Bronco, the O-2A continued to be used for night missions after the OV-10's introduction, due to the OV-10's high level of cockpit illumination, rendering night reconnaissance impractical.[1] The O-2 was phased out completely after additional night upgrades to the OV-10.[2][3]
A total of 178 USAF O-2 Skymasters were lost in the Vietnam War, to all causes.[4]
Following the Vietnam War, the O-2 continued to operate with both
U.S. Air Force and
Air National Guard units into the late 1980s.
Of the six USN aircraft mentioned above, two were transferred to the
U.S. Army in late 1990.[5] USAF O-2As were augmented by the 1990 aircraft transfer from the Navy. Several disassembled USAF O-2s remain in storage at
Davis-Monthan AFB, Arizona.[5] Two O-2As were used at
Laguna Army Airfield, Arizona as part of testing programs carried out by the
Yuma Proving Ground. These were retired in October 2010 and sent to a museum.[6]
During the
Salvadoran Civil War, the
Salvadoran Air Force received a total of 23 O-2As and 2 O-2Bs from the United States, the first arriving in 1981. They were employed to observe the movements of
FMLN formations and direct air strikes against them, playing a major role in forcing the rebel movement to abandon large-scale operations.
Near the end of the war in 1990, the rebels' acquisition of
SA-7 missiles resulted in the loss of two O-2As, while another was destroyed by mortar fire, and two more were lost in crashes.[7]
Civilian use
CAL FIRE
In the mid-1970s, the
California Department of Forestry and Fire Protection, or CAL FIRE, found that the contractor-owned air attack aircraft, mostly single-engine
Cessna 182s and
Cessna 210s, did not provide the airspeed and safety needed for the department's new air tanker program. In 1974, Senior Air Operations Officer Cotton Mason inspected 40 USAF O-2s at
Davis-Monthan Air Force Base. The best 20 were selected and shipped to
Fresno, California. These aircraft had been FAC aircraft in Vietnam and were shipped back to the United States in containers, and were disassembled and on pallets when they arrived at Fresno. A crew of
California Conservation Corps (CCC) members under the supervision of a CDF Battalion Chief, who was an FAA Certificated Mechanic with Inspection Authorization (IA), reassembled the aircraft.
They were placed in service in 1976, and served CAL FIRE for more than 20 years, until replaced by a fleet of
OV-10 Broncos.[8]
Variants
O-2A
Version designed for use in forward air control missions, with underwing ordnance hard points to hold
rockets,
gun pods or
flares. 513 delivered.[3]
O-2B
Version designed for
psychological warfare, equipped with
loudspeakers and a leaflet dispenser, and not armed. Thirty-one former civil 337s were converted to O-2Bs.[9]