The Martin B-26 Marauder
The Martin B-26 Marauder was an American World War II twin-engined medium bomber built by the Glenn L. Martin Company from 1941 to 1945.
First used in the Pacific Theater in early 1942, it was also used in the Mediterranean Theater and in Western Europe.
After entering service with the US Army, the aircraft received the reputation of a “Widowmaker” due to the early models’ high accident rate during takeoffs and landings. The Marauder had to be flown at exact airspeeds, particularly on final runway approach and when one engine was out.
The 150 mph (241 km/h) speed on short final runway approach was intimidating to pilots who were used to much slower speeds, and whenever they slowed down to speeds below what the manual stated, the aircraft would stall and crash.
The B-26 Marauder became a safer aircraft once crews were re-trained, and after aerodynamics modifications (an increase of wingspan and wing angle-of-incidence to give better takeoff performance, and a larger vertical stabilizer and rudder). After aerodynamic and design changes, the aircraft distinguished itself as “the chief bombardment weapon on the Western Front” according to a United States Army Air Forces dispatch from 1946. The Marauder ended World War II with the lowest loss rate of any USAAF bomber.
A total of 5,288 were produced between February 1941 and March 1945; 522 of these were flown by the Royal Air Force and the South African Air Force. By the time the United States Air Force was created as an independent service separate from the Army in 1947, all Martin B-26s had been retired from US service.
Design and development of B-26 Marauder
In March 1939, the United States Army Air Corps issued Circular Proposal 39-640, a specification for a twin-engined medium bomber with a maximum speed of 350 mph (560 km/h), a range of 3,000 mi (4,800 km) and a bomb load of 2,000 lb (910 kg). On 5 July 1939, the Glenn L. Martin Company submitted its design, produced by a team led by Peyton M. Magruder, to meet the requirement, the Martin Model 179.
Martin’s design was evaluated as superior to the other proposals and was awarded a contract for 201 aircraft, to be designated B-26. The B-26 Marauder went from paper concept to an operational bomber in approximately two years. Additional orders for a further 930 B-26s followed in September 1940, still prior to the first flight of the type.
The B-26 Marauder was a shoulder-winged monoplane of all-metal construction, fitted with a tricycle landing gear. It had a streamlined, circular section fuselage housing the crew, consisting of a bombardier in the nose, armed with a .30 in (7.62 mm) machine gun, a pilot, and co-pilot sitting side by side, with positions for the radio operator and navigator behind the pilots.
A gunner manned a dorsal turret armed with two .50 in (12.7 mm) machine guns (the first powered dorsal turret to be fitted to a US bomber), while an additional .30 in (7.62 mm) machine gun was fitted in the tail.
Two bomb bays were fitted mid-fuselage, capable of carrying 5,800 lb (2,600 kg) of bombs, although in practice such a bomb load reduced range too much, and the aft bomb bay was usually fitted with additional fuel tanks instead of bombs.
The aircraft was powered by two Pratt & Whitney R-2800 Double Wasp radial engines in nacelles slung under the wing, driving four-bladed propellers.
The engines were manufactured at the Ford Dearborn Engine plant in Dearborn, Michigan, USA. The wings were of low aspect ratio and relatively small in area for an aircraft of its weight, giving the required high performance, but also resulting in a wing loading of 53 lb/sq ft (259 kg/m²) for the initial versions, which at the time was the highest of any aircraft accepted for service by the Army Air Corps.
The first B-26 Marauder, with Martin test pilot William K. “Ken” Ebel at the controls, flew on 25 November 1940 and was effectively the prototype. Deliveries to the US Army Air Corps began in February 1941 with the second aircraft, 40-1362.
In March 1941, the Army Air Corps started Accelerated Service Testing of the B-26 Marauder at Patterson Field, Ohio.
Accidents of B-26 Marauder
The B-26 Marauder relatively small wing area and resulting high wing loading required a high landing speed of 120 to 135 mph (193 to 217 km/h) indicated airspeed depending on load. At least two of the earliest B-26s suffered hard landings and damage to the main landing gear, engine mounts, propellers, and fuselage. The type was grounded briefly in April 1941 to investigate the landing difficulties.
Two cases were found: insufficient landing speed (producing a stall) and improper weight distribution. The latter was due to the lack of a dorsal turret; the Martin power turret was not yet ready.
Some of the very earliest B-26s suffered collapses of the nose landing gear. It is said that they were caused by improper weight distribution, but that is not likely to have been the only reason. The incidents occurred during low-speed taxiing, takeoffs, and landings, and occasionally the strut unlocked. Later the Martin electric dorsal turret was retrofitted to some of the first B-26s. Martin also began testing a taller vertical stabilizer and revised tail gunner’s position in 1941.
The Pratt & Whitney R-2800-5 engines were reliable, but the Curtiss electric pitch change mechanism in the propellers required impeccable maintenance, not always attainable in the field. Human error and some failures of the mechanism occasionally placed the propeller blades in flat pitch resulting in an overspeeding propeller, sometimes known as a “runaway prop“.
Due to its sound and the possibility that the propeller blades could disintegrate, this situation was particularly frightening for aircrews. More challenging was a loss of power in one engine during takeoff. These and other malfunctions, as well as human error, claimed a number of aircraft and the commanding officer of the 22nd Bombardment Group, Colonel Mark Lewis.
The Martin B-26 Marauder suffered only two fatal accidents during its first year of flight, from November 1940 to November 1941: a crash shortly after takeoff near Martin’s Middle River plant (cause unknown, but engine malfunction strongly suggested) and the loss of a 38th Bombardment Group B-26 when its vertical stabilizer and rudder separated from the aircraft at altitude (cause unknown, but the accident report discussed the possibility that a canopy hatch broke off and struck the vertical stabilizer).
Due to the need for training many pilots quickly for the war, a number of relatively inexperienced pilots entered the cockpit and the accident rate increased accordingly. This occurred at the same time as more experienced B-26 Marauder pilots of the 22nd, 38th and 42nd Bombardment Groups were proving the merits of the bomber.
For a time in 1942, pilots in training believed that the B-26 could not be flown on one engine. This was disproved by a number of experienced pilots, including Jimmy Doolittle.
In 1942, Glenn Martin was called before the Senate Special Committee to Investigate the National Defense Program, or Truman Committee, which was investigating defense contracting abuses. Senator Harry Truman, the committee chairman, asked Martin why the B-26 Marauder had issues. Martin responded that the wings were too short.
Truman asked why the wings were not changed. When Martin said the plans were too far along and besides, his company already had the contract, Truman’s response was quick and to the point: In that case, the contract would be canceled. Martin said corrections to the wings would be made. (By February 1943, the newest model, the B-26B-10, had an additional 6 feet (1.8 m) of wingspan, plus uprated engines, more armor, and larger guns.)
Indeed, the regularity of crashes by pilots training at MacDill Field — up to 15 in one 30-day period — led to the exaggerated catchphrase, “One a day in Tampa Bay.” Apart from accidents occurring over land, 13 Marauders ditched in Tampa Bay in the 14 months between the first airplane on 5 August 1942 to the final one on 8 October 1943.
B-26 Marauder crews gave the aircraft the nickname “Widowmaker“. Other colorful nicknames included “Martin Murderer”, “Flying Coffin“, “B-Dash-Crash“, “Flying Prostitute” (so-named because it was so fast and had “no visible means of support,” referring to its small wings) and “Baltimore Whore” (a reference to the city where Martin was based).
According to an article in the April 2009 edition of AOPA Pilot on Kermit Weeks’ “Fantasy of Flight“, the Marauder had a tendency to “hunt” in yaw. This instability is similar to “Dutch roll”. This would make for a very uncomfortable ride, especially for the tail gunner.
The B-26 Marauder is stated by the 9th Air Force to have had the lowest combat loss rate of any US aircraft used during the war. Nevertheless, it remained a challenging aircraft to fly and continued to be unpopular with some pilots throughout its military career.
In 1944, in answer to many pilots complaining to the press and their relatives back home, the USAAF and Martin took the unusual step during the war, of commissioning large articles to be placed in various popular publications, “educating” and defending the so-called flying/accident record of the B-26 against “slanders“. One of the largest of these articles was in the May 1944 issue of Popular Mechanics.
The B-26 Marauder was used mostly in Europe, but also saw action in the Mediterranean and the Pacific. In early combat, the aircraft took heavy losses, but was still one of the most successful medium-range bombers used by the US Army Air Forces.
The B-26 was initially deployed on combat missions in the South West Pacific in the spring of 1942, but most of the B-26s subsequently assigned to operational theaters were sent to England and the Mediterranean area.
By the end of World War II, it had flown more than 110,000 sorties, dropped 150,000 tons (136,078 tonnes) of bombs and had been used in combat by British, Free French and South African forces in addition to US units. In 1945, when B-26 production was halted, 5,266 had been built.
The B-26 Marauder began to equip the 22nd Bombardment Group at Langley Field, Virginia, in February 1941, replacing the Douglas B-18 Bolo, with a further two groups, the 38th, and 28th, beginning to equip with the B-26 by December 1941.
Immediately following the Japanese Attack on Pearl Harbor, the 22nd BG was deployed to the South West Pacific, first by ship to Hawaii, then its air echelon flew the planes to Australia. The 22nd BG flew its first combat mission, an attack on Rabaul which required an intermediate stop at Port Moresby, New Guinea, on 5 April 1942.
A second group, the 38th, began receiving B-26s in November 1941 and began transitioning into them at Patterson Field, Ohio. There, the 38th continued the testing of the B-26, including its range and fuel efficiency.
Immediately after the entry of the United States into World War II, plans were tentatively developed to send the 38th BG to the South West Pacific and to equip it with B-26Bs fitted with more auxiliary fuel tanks and provisions for carrying aerial torpedoes.
Three 38th BG B-26Bs were detached to Midway Island in the buildup to that battle, and two of them, along with two B-26s detached from the 22nd BG, carried out torpedo attacks against the Japanese Fleet on 4 June 1942.
Two were shot down and the other two were so badly damaged that they were written off after the mission.
Their torpedoes failed to hit any Japanese ships, although they did shoot down one Mitsubishi A6M Zero fighter and killed two seamen aboard the aircraft carrier Akagi with machine-gun fire.
Notably, one of them, Susie Q, after dropping its single torpedo and searching for a safer escape route, flew directly down the length of the Akagi while being chased by interceptors and anti-aircraft fire, which had to hold their fire to avoid hitting their own flagship.
From approximately June 1942, B-26 Marauder squadrons of the 38th BG were based in New Caledonia and Fiji. From New Caledonia, missions were flown against Japanese bases in the Solomon Islands.
On one occasion, a B-26 was credited with shooting down a Kawanishi H6K flying boat. In 1943, it was decided that the B-26 Marauder would be phased out of operations in the South West Pacific Theatre in favor of the North American B-25 Mitchell.
Nevertheless, the 19th Bombardment Squadron of the 22nd BG continued to fly missions in the B-26.
The B-26 flew its last combat mission in the theatre on 9 January 1944.
Two more squadrons of torpedo-armed B-26s equipped the 28th Composite Group and were used for anti-shipping operations in the Aleutian Islands Campaign, but there are no records of any successful torpedo attack by a USAAF B-26.
Three Bombardment Groups were allocated to support the Allied invasion of French North Africa in November 1942.
They were initially used to carry out low-level attacks against heavily defended targets, incurring heavy losses with poor results, before switching to medium level attacks.
By the end of the North African Campaign, the three B-26 groups had flown 1,587 sorties, losing 80 aircraft. This was double the loss rate of the B-25, which also flew 70% more sorties with fewer aircraft.
Despite this, the B-26 continued in service with the Twelfth Air Force, supporting the Allied advance through Sicily, Italy, and southern France.
Air Marshal Sir John Slessor, Deputy Commander-in-Chief Mediterranean Allied Air Forces, wrote of “the astonishing accuracy of the experienced medium bomber groups – particularly the Marauders; I think that the 42nd Bombardment Group in Sardinia is probably the best day-bomber unit in the world.”
Slessor, in fact, meant the 42nd Bomb Wing—17th, 319th and 320th Bomb Groups—but a US ‘wing’ equated roughly to a British ‘group’, and vice versa.
The B-26 Marauder entered service with the Eighth Air Force in England in early 1943, with the 322nd Bombardment Group flying its first missions in May 1943. Operations were similar to those flown in North Africa with B-26s flying at low level and were unsuccessful.
The second mission, an unescorted attack on a power station at IJmuiden, Netherlands, resulted in the loss of the entire attacking force of 11 B-26s to anti-aircraft fire and Luftwaffe Focke-Wulf Fw 190 fighters.
Following this disaster, the UK-based B-26 force was switched to medium altitude operations, and transferred to the Ninth Air Force, set up to support the planned invasion of France.
Bombing from medium altitudes of 10,000 to 15,000 feet (3,000 to 4,600 m) and with appropriate fighter escort, the Marauder proved far more successful, striking against a variety of targets, including bridges and V-1 launching sites in the buildup to D-Day, and moving to bases in France as they became available.
The Marauder, operating from medium altitude, proved to be a highly accurate aircraft, with the 9th Air Force rating it the most accurate bomber available in the final month of the war in Europe. Loss rates were far lower than in the early, low-level days, with the B-26 stated by the 9th Air Force as having the lowest loss rate in the European Theatre of Operations at less than 0.5%.
The B-26 Marauder flew its last combat missions against the German garrison at the Île d’Oléron on 1 May 1945, with the last units disbanding in early 1946.
In 1942, a batch of 52 B-26A Marauders (designated Marauder I by the RAF) was offered to the United Kingdom under Lend-Lease. Like the earlier Martin Maryland and Baltimore, these aircraft were sent to the Mediterranean, replacing the Bristol Blenheims of No. 14 Squadron in Egypt. The Squadron flew its first operational mission on 6 November 1942, being used for long-range reconnaissance, mine-laying, and anti-shipping strikes.
Unlike the USAAF, 14 Squadron made productive use of the equipment for carrying torpedoes, sinking several merchant ships with this weapon. The Marauder also proved useful in disrupting enemy air transport, shooting down considerable numbers of German and Italian transport aircraft flying between Italy and North Africa.
In 1943, deliveries of 100 long-wingspan B-26C-30s (Marauder II) allowed two squadrons of the South African Air Force, 12 and 24 Squadron to be equipped, these being used for bombing missions over the Aegean Sea, Crete, and Italy.
A further 350 B-26Fs and Gs were supplied in 1944, with two more South African squadrons (21 and 30) joining No 12 and 24 in Italy to form an all-Marauder equipped wing, while one further SAAF squadron (25) and a new RAF squadron (39 Squadron), re-equipped with Marauders as part of the Balkan Air Force supporting Tito’s Partisans in Yugoslavia.
A Marauder of 25 Squadron SAAF, shot down on the unit’s last mission of World War II on 4 May 1945, was the last Marauder lost in combat by any user.
The British and South African aircraft were quickly scrapped following the end of the war, the United States not wanting the return of the Lend-Lease aircraft.
Following Operation Torch, (the Allied invasion of North Africa), the Free French Air Force re-equipped three squadrons with Marauders for medium-bombing operations in Italy and the Allied invasion of southern France. These B-26s replaced Lioré et Olivier LeO 451s and Douglas DB-7s.
Toward the end of the war, seven of the nine French Groupes de Bombardment used the Marauder, taking part in 270 missions with 4,884 aircraft sorties in combat.
Free French B-26 Marauder groups were disbanded in June 1945. Replaced in squadron service by 1947, two lingered on as testbeds for the Snecma Atar jet engine, one of these remaining in use until 1958.