The Martin B-26 Marauder was one of the more controversial American aircraft of the Second World War, earning an early reputation as a killer aircraft before going on to suffer the lowest loss rate of any American bomber in the European theatre.
The Marauder was designed to satisfy Circular Proposal 39-640 of 11 March 1939 which called for a high speed light or medium bomber, capable of carrying 3,000lb of bombs 2,000 miles with a top speed of over 300mph. It had to be capable of operating between 8,000 and 14,000ft, and was to be used to support ground troops.
The Martin 179, designed by Peyton M. Magruder, was for an aircraft with a torpedo or cigar shaped fuselage, two massive radial engines, a nose-wheel undercarriage and short stubby wings. It was originally designed with a twin tail, but in October 1939 that was replaced with the single fin and rudder of the final design.
The winner of Proposal 39-640 was decided by allocated each design a number of quality points. The Martin 179 was the clear winner, with 813.6 points, followed by the North American NA-62. The army had wanted to order 385 examples of the winning aircraft, but Martin could only produce 201 aircraft, and so North American were rewarded with a contract for 184 NA-62s, as the B-25.
The first B-26 made its maiden flight on 25 November 1940, with Ken Ebel, Martin's chief engineer, at the controls. This and the next three aircraft were then used for testing and service evaluation, while at the same time production continued on the remaining aircraft.
The early service tests, in December 1940 and January 1941, went well. In the hands of experienced pilots the fully equipped aircraft had a service ceiling of 25,000ft, a top speed of 323mph and a range of 3,000 miles at 15,000ft. The new aircraft had the highest wing loading of any aircraft yet accepted by the USAAC, making it tricky to handle at low speeds, had a high landing speed (over 100mph) and a long takeoff run, but despite this on 8 February 1941 the B-26 was accepted for service.
In the same month the 22nd Bombardment Group at Langley Field became the first unit to receive the B-26. The new aircraft almost immediately ran into the problems that would earn it the nicknames 'widow maker' or 'the separator' (for separating the men from the boys). The B-26 was the first of a series of aircraft ordered 'off-the-shelf', without a prototype or a prolonged period of development, and it entered service only three months after its first flight.
Some problems were easy to fix. At first the aircraft delivered to Langley Field lacked the guns, radios and armour – all items installed by the Army not by Martin. The lack of the dorsal turret was a particular problem as it altered the centre of gravity, making the aircraft nose heavy. The result was a series of crashes caused by failure of the nose gear. These only ended when the full armament was installed.
A second problem was that the B-26 used many more electrical systems than earlier aircraft, including the power operated turret and the Curtiss- Electric propeller. The propeller developed a dangerous habit of failing at take-off, when it was under the most stress. Eventually this was traced to a problem with the servicing of the new aircraft – the internal batteries were being used during maintenance on items like the power turret, draining them of power. When the aircraft was next used the flat battery would fail, causing the propellers to feather and the aircraft to crash. This problem was solved by providing the ground crew with portable batteries for services.
The third problem was harder to solve. The B-26 was a 'hot' aircraft, unforgiving at low speeds, not well suited to aerobatics and with a number of new features, including the nose-wheel landing gear. This hadn't caused any problems during the brief test period when the aircraft was in the hands of experienced pilots, but in 1941 and especially at the start of 1942 the aircraft was being flown by large numbers of new pilots, many of whom came to it directly from the North American AT-6 Texan, a single engined aircraft with tail-wheel landing gear and a top speed of 205mph.
This problem was eventually solved in three ways. Physically the aircraft was given longer wings (starting with the 982nd aircraft). This made it slower but easier to handle. The training programme was extended to include a period of advanced training in the twin-engined Curtiss AT-9. Finally as the training staff became more familiar with the type the quality and usefulness of the training increased dramatically, and the accident rate dropped from a high of 162 accidents for every 100,000 hours of flying time in 1942 down to 37 in 1944.
The Marauder entered combat with the 22nd Bombardment Group on 5 April 1942, in an attack on Rabaul. The same year saw it enter service with the RAF in the western desert, and it was only the enthusiastic reports that came from the South Pacific and North Africa that kept the B-26 in production during 1942. The Marauder was used in most theatres of the war in some numbers, but it was most important in the European theatre, at first with the Eighth Air Force and then in larger numbers with the tactical Ninth Air Force. At its peak in March 1944 the USAAF had 1,931 Marauders on its books, while the Ninth Air Force still had 1,012 in theatre in November and 800 on its books at the end of the war. By this time the B-26 had redeemed itself, and after a very shaky start had become the safest of all American bombers in the European theatre, with the lowest loss rate.
By then many Marauder groups had converted to the A-26 Invader, and only three of the Ninth's eight groups survived to join the post-war occupation forces in Germany. The last aircraft were deactivated in February 1946, and it was completely gone from the inventory by the end of the year. The B-26 disappeared so quickly for a number of reasons. It was more expensive to build than the B-25, not as modern as the A-26, and never entirely escaped from its early reputation as a dangerous aircraft.