submitted by: Alva Leon Matheson

In 1966, the US Air Force chose the Cessna Model 337 “Super Skymaster” to meet the twin engine Forward Air Controller (FAC) aircraft requirement. Designated the O-2, it was needed to supplement the Cessna O-1 Bird Dog FAC aircraft then operating in Southeast Asia. The Skymaster was an all metal, four seat business aircraft designed by Cessna to be easy to fly, low in cost, yet still offer the safety and comfort of a twin engine plane. The USAF version first flew in January 1967 and the first delivery to the USAF was in March 1967. A total of 532 aircraft were built between 1967 and June 1970 when production ceased.
The “Super Skymaster” was already on the production line when the Air Force awarded the contract. Modifications were made. A gun sight was installed along with underwing pylons for smoke rockets, the 7.62 mm minigun pack, flares, and cluster bombs. Other changes included a smoke generator, glass panels in the lower starboard door for increased visibility, a loud speaker for psychological warfare, armament switch subpanels, additional windows in the fuselage, avionics, spartan interiors and exterior paint scheme. The O-2s were used in the FAC role for airstrike control, artillery adjustment, reconnaissance, target identification, damage assessment and air to ground coordination. Some aircraft were even equipped with three 600 Watt amplified speakers and leaflet pods for psychologi- cal warfare operations. The O-2 could fly on either engine by itself at light weights but when loaded for combat operations the O-2 gradually lost altitude following the failure of one engine; unless at very low altitude. Only 31 O-2Bs were ordered from Cessna by the U.S. Air Force.
O-2B 21465 was used for psychological warfare operations (only), dropping leaflets with many different messages, some instructional, but mostly warnings of impeding defoliation flights or exhorted enemy troops to lay down their arms. No. 21465 was also equipped with a 300 pound 1,800 watt amplified speaker sys- tem. The effectiveness of the loud speaker and leaflets was judged by the fact that the VC shot at the psywar aircraft more than at any other, except those of Operation Ranch Hand (defo- liant C-123s). The VC also banged pots and pans together in hamlet streets to drown out the speakers, and cut off the hands of villagers caught reading the leaflets.
Distinguished by twin tail booms and tandem-mounted engines, it features a tractor-pusher propeller arrangement. Having twin engines enabled the O-2 to absorb more ground fire and still return safely, endearing it to its crews. Production ended in June 1970 after 532 O-2s had been built for the USAF.
The FAC mission required an airplane with easy maneuverability and agility to avoid ground fire while pulling out of a dive. Thus the pilot would prefer light elevator control forces while pulling sizable “g” forces in pull-outs and turns. To achieve this goal the stability-enhancing elevator downspring and bobweight devices from the civilian C-337B was removed. In addition, the elevator was replaced with the four-inch shorter chord elevator used on the C-336. With the resulting penalty in elevator power in landings at forward loadings, the allowable most-forward C of G limit was moved aft by 1.5 inches. These changes added significantly to the flying qualities, and in fact, they were later adopted in the commercial C-337s at the urging of Mort Brown, Chief of Production Flight Test. Mort had been testing O-2 and C-337 airplanes in sequence, and he noted the much nicer “feel” of the O-2 airplanes. Consequently, the stability devices were removed from the 1968 C-337C, and starting with the 1969 C-337D the small chord elevator was adopted as well.
Armor plates were installed under the seats and porous foam slabs added to the fuel tanks (before assembly) to make them explosion-resistant after a gunfire hit. This was at the expense of about a 5 % loss in tank capacity. Most of the development effort was focused on external armaments suspended from the wing pylons. In addition to the primary military objective of target-marking with smoke rockets, the aerodynamic effects of bombs, attack rockets, mini-machine gun pods, wire-laying containers, and a host of bulky cargo containers of unbelievable size were tested. The intent was to make sure that the airplane was controllable (at vastly increased gross weights) with both symmetrical and asymmetrical loads. In addition, determining that the jettisonable external stores could be safely jettisoned at various speeds without striking the tail was accomplished.
Span: 38 feet.
Length: 29 ft 2 in.
Height: 9 ft 5 in.
Weight: 4,900 pounds loaded.
Armament: Four wing pylons can carry rockets, flares, 7.62 mini-gun pods, or other light ordnance.
Engines: Two Continental 10-360s of 210 hp each. Crew: Two.
Maximum speed: 199 mph. Cruising speed: 144 mph. Range: 1,060 miles.
Service Ceiling: 19,300 feet.