In preparation for large-scale introduction of the Marauder into combat, the USAAF had set up B-26 Transition Training Fields at MacDill Field, Tampa, Florida and at Barksdale Field, Shreveport, Louisiana. Nine new USAAF medium bomber groups had been activated in 1942 as Marauder-equipped units.
Unfortunately, many of the pilots trying to master the Marauder at these fields had no previous twin-engined experience. In 1942, a series of training accidents took place stateside which placed the future of the entire Marauder program in doubt. Most of these accidents took place during takeoff or landing. The increases in weight that had been gradually introduced on the production line had made the wing loading of the Marauder progressively higher and higher, resulting in higher stalling and landing speeds. Veteran pilots in combat overseas had enough experience that they could handle these higher speeds, but new trainees at home had serious problems and there were numerous accidents, causing the Marauder to earn such epithets as "The Flying Prostitute", "The Baltimore Whore", "The Flying Vagrant", or "The Wingless Wonder", these names being given because the B-26's small wing area appeared to give it no visible means of support. Other derisive names being given to the B-26 were "The Widow Maker", "One-Way Ticket", "Martin Murderer", "The Flying Coffin", "The Coffin Without Handles", and the "B-Dash Crash". In particular, there were so many takeoff accidents at MacDill Field at Tampa, FL during early 1942 that the phrase "One a Day Into Tampa Bay" came to be a commonplace lament.
While it was true that the wing loading of the B-26 was rather large and the stalling speed was well beyond what most of the trainees were used to, the primary problem with the B-26 was the propellers, which tended to runaway and feather during takeoff on a regular basis. The low speed of the planes as they cleared the runway on takeoff over Tampa Bay plus th drage of the feathered props made for a dangerous combination. Typically, a plane so affected would suddenly flip over toward the feathered prop--since the plane was still at low altitude there was little time for corrective action and the plane would quickly plunge into the bay.
The USAAF was concerned about the high accident rate and seriously considered withdrawing the Marauder from production and service. The US Senate's Special Committee to Investigate the National Defense Program (better known as the Truman Committee, after its chairman, Sen. Harry S Truman of Missouri), which had been charged with ferreting out corruption, waste, and mismanagement in the military procurement effort, also began looking into the Marauder's safety record. In July the Committee recommended that B-26 production be stopped. However, combat crews in the South Pacific were more experienced and were not having any particular problems with the airplane, and they went to bat for the Marauder. They exerted pressure, and the USAAF decided to continue with production of the Marauder.
However, by September of 1942, the situation had gotten even worse and training accidents had become even more frequent. By that time, the reputation of the Marauder had gotten so bad that civilian crews contracted to ferry USAAF aircraft to their destinations were often quitting their jobs rather than having to ferry a B-26. The Air Safety Board of the USAAF was forced to initiate an investigation into the cause. In October, the Truman Committee was again on the warpath and once again recommended that production of the B-26 be discontinued.
USAAF commanding General Henry. H. Arnold directed that Brig. General James H. Doolittle (fresh from his famous Tokyo raid) investigate the problem with the B-26 personally. Doolittle had recently been given command of the B-26-equipped 4th Medium Bombardment Wing, which was scheduled to take part in the invasion of North Africa.
Both General Doolittle and the Air Safety Board concluded that there was nothing intrinsically wrong with the B-26, and there was no reason why it should be discontinued. They traced the problem to the inexperience of both aircrews and ground crews, and also to the overloading of the aircraft beyond the weight at which it could be safely flown on one engine only. Almost immediately after the Marauder had entered service, it had been found necessary to add more and more equipment, armament, fuel, and armor, driving the gross weight steadily upwards. By early 1942, the B-26 had risen in normal gross weight from its original 26,625 pounds to 31,527 pounds with no increase in power. It had been found that many of the accidents had been caused by engine failures, which were in turn caused by a combination of poor maintenance by relatively green mechanics and a change from 100 octane fuel to 100 octane aromatic fuel, which damaged the diaphragm of the carburetors. Many of the B-26 instructors were almost as green as the pilots they were trying to train, and did not know themselves how to fly the B-26 on one engine only, and so could not teach the technique to their students.
General Doolittle sent his technical adviser, Captain Vincent W. "Squeak" Burnett, to make a tour of OTU bases to demonstrate how the B-26 could be flown safely. These demonstrations included single-engine operations, slow-flying characteristics, and recoveries from unusual flight attitudes. Capt Burnett made numerous low altitude flights with one engine out, even turning into a dead engine (which aircrews were warned never to do), proving that the Marauder could be safely flown if you knew what you were doing. General Doolittle himself carried out some demonstration flights with the B-26 in which he cut an engine on takeoff, rolled over, flew the plane upside down at an extremely low altitude for a distance, and then righted it safely. Martin also sent engineers out into the field to show crews how to avoid problems caused by overloading, by paying proper attention to the plane's center of gravity.
However, the decision was made to increase the wing area in order to lower the wing loading, reducing the takeoff and landing speeds and hopefully cutting down on the number of takeoff and landing accidents.
The new wing was first introduced on the B-26C production block at Omaha, and did not appear on the B-26B line at Baltimore until the introduction of the B-26B-10-MA production block, which first appeared in January of 1943. The wing span increased from 65 to 71 feet and area increased from 602 to 658 square feet. A taller fin and rudder was introduced to maintain stability with the larger wing, increasing overall height from 19 feet 10 inches to 21 feet 6 inches.
However, the advantages of the reduced wing loading were partially offset by an increase in gross weight to 38,200 pounds as the result of the fitting of additional armament. A total of twelve 0.50-inch machine guns were now carried. These comprised a flexible 0.50-inch nose gun with 270 rounds, a single fixed gun on the starboard side of the nose with 200 rounds, two "package" guns on each side of the fuselage below the cockpit with 200-250 rpg, two 0.50-inch guns in the rear dorsal turret, two 0.50-inch guns in the beam, and two 0.50 inch guns in the tail. Nevertheless, at a takeoff weight of 36,000 pounds, the takeoff run was reduced from 3150 to 2850 feet. However, the larger wing area resulted in a decrease in maximum speed from 289 to 282 mph.
Even before all the design changes had been put on the production line, the efforts of the Army and Martin to improve training began to pay off, and accidents at training fields began to fall off, and within a month had reached a fairly low level. The Truman Committee finally relented, and stopped its demands for the cessation of Marauder production. Nevertheless, the derogatory nicknames still persisted, and word had not gotten down to the grass roots level that the problems with the B-26 had been largely corrected. Pilot students still believed that the B-26 was a deathtrap, and very few graduates requested assignment to a B-26 group. A number of pilots still refused to fly the plane even in spite of the lowered accident rate, and had to be reassigned to other units.