20 AT-6 Texans were employed by the 1st and 2nd fighter squadrons of the Syrian Air Force in the 1948 Arab-Israeli War, providing ground support for Syrian troops, and launching air strikes against Israeli airfields, ships, and columns, losing one aircraft to anti-aircraft fire. They also engaged in air-to-air combat on a number of occasions, with a tail gunner shooting down an Israeli Avia S-199 fighter.
The Israeli Air Force (IAF) bought 17 Harvards, and operated nine of them in the final stages of the 1948 Arab-Israeli War, against the Egyptian ground forces, with no losses. In the Sinai Campaign IAF Harvards attacked Egyptian ground forces in Sinai Peninsula with two losses.
The Royal Hellenic Air Force employed three squadrons of British and American supplied T-6D and G Texans for close air support, observation, and artillery spotting duties during the Greek Civil War, providing extensive support to the Greek army during the Battle of Gramos. Communist guerillas called these aircraft "O Galatas" ("The Milkman"), because they saw them flying very early in the morning. After the "Milkmen", the guerillas waited for the armed Spitfires and Helldivers.
During the Korean War and, to a lesser extent, the Vietnam War, T-6s were pressed into service as forward air control aircraft. These aircraft were designated T-6 "Mosquitos".
No. 1340 Flight RAF used the Harvard in Kenya against the Mau Mau in the 1950s, where they operated with 20 lb bombs and machine guns against the gangs. Some operations took place at altitudes around 20,000 ft above mean sea level. A Harvard was the longest-serving RAF aeroplane, with an example, taken on strength in 1945, still serving in the 1990s (as a chase plane for helicopter test flights—a role for which the Shorts Tucano's high stall speed was ill-suited).
The T-6G was also used in a light attack or counter insurgency role by France during the Algerian war in special Escadrilles d'Aviation Légère d'Appui (EALA), armed with machine guns, bombs and rockets. At its peak, there were 38 EALAs active. The largest unit was the Groupe d'Aviation Légère d'Appui 72, which consisted of up to 21 EALAs.
From 1961 to 1975, Portugal used more than a hundred T-6Gs, also in the counter insurgency role, during the Portuguese Colonial War. During this war, almost all the Portuguese Air Force bases and air fields in Angola, Mozambique and Portuguese Guinea had a detachment of T-6Gs.
In 1955, Argentine Navy SNJ-4s were dispatched to attack government troops on June 16 during the Revolución Libertadora and one was shot down by a loyalist Gloster Meteor. Argentine Navy SNJ-4s were also were used by the Colorado rebels in the 1963 Argentine Navy Revolt, launching attacks on the 8th Regimiento de Caballería de Tanques on April 2 and 3, knocking out several M4 Sherman tanks but losing one SNJ to anti-aircraft fire.
In 1957-58, the Spanish Air Force used T-6s as counterinsurgency aircraft in the Ifni War, armed with machine guns, iron bombs and rockets, achieving an excellent reputation due to its reliability, safety record and resistance to damage.
The Pakistan Air Force used T-6Gs in the 1971 war as a night ground support aircraft hitting soft transport vehicles of the Indian army. In the early hours of 5 December, during a convoy interdiction mission in the same area, Squadron Leader Israr Quresh's T-6G Harvard was hit by Indian anti-aircraft ground fire and a shell fractured the pilot’s right arm. Profusely bleeding, the pilot flew the aircraft back with his left hand and landed safely. The World War II vintage prop-engined trainers were pressed into service and performed satisfactorily in the assigned role of convoy escorters at night.
T-6s remained in service, mainly as a result of the United Nations arms embargo against South Africa's Apartheid policies, with the South African Air Force as a basic trainer until 1995. They were replaced by Pilatus PC-7MkII turboprop trainers.
Recent research testbed
The Harvard 4 has also been recently used in Canada as a testbed aircraft for evaluating cockpit attitude displays. Its aerobatic capability permits the instructor pilot to maneuver the aircraft into unusual attitudes, then turn the craft over to an evaluator pilot in the "blind" rear cockpit to recover, based on one of several digitally-generated attitude displays.