However, the Invader was not very popular in the Pacific theatre since it had poor visibility to either side and lacked sufficiently powerful forward-firing armament to make it an effective strafer.
Deliveries of the A-26 to the 9th Air Force in the European theater began in June of 1944. However, it was not until September 17, 1944 that their first combat missions were flown. This first mission was carried out by the 553rd Bombardment Squadron of the 386th Bombardment Group, based at Great Dunmow in England. It was a medium-altitude bombing strike in which B-26Bs led a bombing strike carried out largely by glazed-nosed A-20Ks.
In the meantime, the USAAF had decided that the European theatre would be the first to get Invaders in quantity, with the Pacific theatre having to wait until improved aircraft with clamshell-type canopies and heavier forward-firing armament could be made available.
A-26B and C Invaders were delivered to the Ninth and Twelfth Air Forces in Europe, The first operational unit to be fully equipped with A-26Bs was the 416th Bombardment Group of the Ninth Air Force, which converted from A-20 Havocs to Invaders in November of 1944. A-26s were eventually delivered to the 409th, 386th, and 391st Bombardment Groups of the Ninth Air Force in early 1945. At the time of the end of the war in Europe, the 410th BG was in the process of converting to A-26s. The last combat mission of the war in Europe was flown by 124 A-26s on May 3, 1945. During the war in Europe, A-26s flew a total of 11,567 sorties.
In the Italian theatre, the 47th BG of the Twelfth Air Force flew A-26s alongside its A-20s during the last four months of the war. The 47th Bomb Group in Italy also received some A-26s in 1945, but returned to the United States in July for specialized training in night attacks. Its black-painted A-26Cs were equipped with radar and served with the group until being replaced by B-45 Tornados in 1948.
As mentioned above, the large-scale introduction of the A-26 into combat in the Pacific was delayed by initial problems with cockpit visibility and inadequate forward-firing armament. In the Pacific theatre, the 319th BG of the Seventh Air Force was the only unit that was fully operational with the A-26 by the time that the war against Japan ended. At that time, the 41st BG of the Seventh Air Force and the 3rd BG of the Fifth Air Force were in the process of converting to A-26s.
On all fronts, the A-26 was regarded as being the USAAF's best twin-engined bomber, and plans were being made at the end of the war for the conversion of all B-25, B-26, and A-20 units to the type.
The end of the war against Japan resulted in the cancellation of the two A-26 contracts on August 13 and 27, respectively. Nevertheless, the A-26 was selected as the standard light bomber and night reconnaissance aircraft of the postwar USAAF, primarily as the main offensive weapon of the Tactical Air Command which was created in 1946 out of the remnants of the wartime 9th and 12th Air Forces. A-26s were also provided to the Air National Guard and to units of the Air Force Reserve. Additional A-26s were sold as surplus, scrapped, or stored for later use. A few were transferred to the US Navy for use as target tugs and general utility aircraft under the designation JD-1.
In June of 1948, the Air Force decided that it no longer needed light attack bombers, and the Attack designation category was officially eliminated. The designation of the two Invader types was changed to B-26B and B-26C respectively. There was no danger of confusion with the Martin B-26 Marauder, since that aircraft was by that time out of service.
The B-26-equipped 3rd Bomb Group ended up being stationed in Japan with the occupation forces. After 1948, it was the only light bomber unit still operating with the USAF.
The B-26B returned to Europe during the early years of the Cold War when the 126th Bomb Wing (L), which was an Air National Guard wing ordered to active duty in April of 1951, set up shop at the Bordeaux-Merignac airfield in France in December of 1951. The 126th was the first tactical USAF wing to be stationed in France since the withdrawal following World War II. They flew a mixture of B-26B and B-26C aircraft, all of them in World War II configuration. The wing was later reorganized as the 38th BW(L). The 117th Tactical Recon Wing (another activated Air National Guard Wing) operated the RB-26C reconnaissance aircraft which was unarmed and carried cameras and flash flares for night photography. The 117th TRW morphed into the 10th TRW in July of 1952.
When the North Korean army invaded the South on June 25, 1950, the USAF was critically short of light bombers. In particular, the 1054 B-26s that were still officially in the USAF inventory were mostly in reserve units or in storage. The only B-26 group available to intervene in Korea was the 3rd Bombardment Group (8th, 13th and 90th Bombardment Squadrons), which was based at Johnson Air Base in Japan. The 3rd BG was equipped primarily with the the solid-nosed B-26B, but some transparent-nosed B-26Cs were also on strength. They were immediately thrown into action, initially flying reconnaissance sorties over the invading North Korean armies which were rapidly overrunning the South. With eight 0.50-inch machine guns in the nose and up to six 0.5-inch guns in the wings some of the B-26B bombers had 14 forward-firing guns. Their first mission was on June 28, 1950 when they attacked railroads supplying enemy forces. Their first attack against North Korea was on June 29, when they bombed the main airfield in Pyongyang.
To meet the emergency needs of the Korean War, the 452nd Bombardment Group (Light), an Air Force Reserve unit out of Long Beach, California, was called to active duty. It was made up of four full squadrons. While their pilots and crews underwent a refresher training course at George AFB in California, their planes were overhauled at Hill AFB. Three of the squadrons (728th, 719th, and 730th) were based for a short while at Miho, Japan before going on to Pusan in South Korea. The fourth squadron (the 731st) was experienced at night flying and was attached to the 3rd Bomb Group, bringing the 3rd up to full strength. It flew its first combat mission on October 27, 1950. It was an attack on enemy supply dumps and troop buidups around the city of Chong-Ju.
During the Korean War, the two units were redesignated 3rd and 17th Bombardment Wing, respectively. The 17th Bomb Wing renumbered its squadrons as the 34th, 37th, and 95th Bomb Squadrons. The two groups flew a total of 55,000 interdiction sorties throughout the war, at first in both day and night conditions and later almost exclusively at night. They were credited with the destruction of 38,500 enemy vehicles, 3700 railway cars, 406 locomotives, and seven aircraft. During the Korean War, 226 B-26s were lost to all causes, including 56 to enemy action. One B-26 pilot, Captain John Wolmsley, was posthumously awarded the Medal of Honor.
Invaders were also flown in the night reconnaissance role by the 162nd Tactical Reconnaissance Squadron (12th TRS after February 1951). Operating as part of the 67th Tactical Reconnaissance Wing, they flew without any defensive armament usually at night to uncover targets and then acted as airborne controllers to vector other aircraft onto the targets that they had pinpointed. A few of the aircraft were fitted with APA-64 to locate enemy radar stations.
For Korean War combat operations, the Invader operated at considerably higher weights and with greater loads than had been achieved in World War 2. For example, the B-26B mounted eight nose guns and had three guns in each wing with a total of 4000 rounds; the four turret guns with 500 rpg, and an offensive load of 4000 pounds of bombs could be carried in the internal bay and fourteen 5-inch HVARs under the wings. Two 165-US gallon fuel tanks or two 110-gallon napalm tanks could replace some of the HVARs. The gross weight often reached 38,500 pounds. The B-26C had the same underwing loads as the B and carried the same two defensive turrets. The C could carry H2S radar on an installation in the fuselage between the nose wheel and the bomb bay. The use of radar made it possible for the B-26C to carry out effective bombing attacks at night.
The A-26 had the honor of flying the last combat sortie of the Korean War, when, 24 minutes before the cease fire went into effect on July 27, 1953 a B-26 of the 3rd BW dropped the last bombs of the Korean war.
Following the end of the Korean War, the A-26s began to be withdrawn from active service with TAC and replaced by jet-powered equipment such as the Martin B-57 and the Douglas B-66. The B-26 remained in service with the Air Force Reserve and the Air National Guard after having been retired by TAC.
When American forces first began to get involved in combat in Vietnam--at first only as advisers--B-26Bs and B-26Cs went into action in the counterinsurgency role with the Farm Gate detachment. Unfortunately, by this time the B-26s were nearing the end of their service lives and suffered from frequent wing failures, forcing them out of service. Those few that remained active were provided with a strengthening wing strap along the bottom of the wing spars to prevent catastrophic wing failures and prolong service life. The success of these modifications led the USAF to order a remanufactured version of the Invader from the On Mark Engineering Company of Van Nuys, California that would be specifically adapted to the counterinsurgency role. The designation B-26K was applied and the name Counter Invader was chosen.
The B-26K Counter Invaders were delivered to the USAF between June 1964 and April 1965. They served with the 603rd Special Operations Squadron based at Lockbourne AFB and Hurlburt AFB in the operational training role, and with the 606th Air Commando Squadron (later renamed the 609th Special Operations Squadron) from Nakhon Phanom Air Base in Thailand. During the mid-1960s, Thailand did not permit the basing of bombers on its territory, and so the aircraft were reassigned the old attack designation of A-26A, thus bringing the Invader full-circle. The A-26As flew night interdiction missions over the Ho Chi Minh trail until they were phased out of service in November of 1969, finally bringing the era of Invader combat service with the USAF to a close.
The last US military Invader, a VB-26B (44-34160) operated by the
National Guard Bureau, was retired in 1972 and was donated to the
National Air and Space Museum