It was on July the 16'th 1935 that the model 299 rolled out of the Boeing Factory in Seattle. The plane was meant as a design submission for the US Army Air Corps for a replacement for the Martin B-10 Bombers which although groundbreaking with its motorized turret, internal bomb bay and completely enclosed cabins for its crew members, fell short in range and by it not having self sealing tanks. The B-10 was used by the Dutch and the Chinese against Japan in the first couple of months of the second world war and it was hopelessly inadequate when it came to defending itself against Japanese fighters. So Boeing, Douglas and Martin sent designs for the 1934–1935 bomber design competition. Here's what they came up with. Martin came up with the 146 which basically was a reworked B-10 but with a wider fuselage which allowed for a pilot and co pilot to sit side by side. It also meant that it could carry a larger bomb load and more fuel. The 146 from another angle, showing the redesigned fuselage with smoothed over rear canopy. The 146 wasn't satisfactory in its performance and was rejected but not all was lost as the R&D team with Martin had gained valuable experience and information which they used for creating the B-26 Marauder only a few years later. Douglas came up with the DB-1 Which basically was a dedicated bomber version of their successful DC-3 airliner. and once you know it, it's impossible NOT to see the resemblance. Although, it sure didn't inherit the DC-3's good looks. And Boeing came up with the 299, which greatly impressed the high command because of it showing just much Boeing was thinking outside the box, bigger plane, means bigger bomb load but there also was a LOT of thought being put into the defensive capabilities as both the Martin and Douglas designs contended with just two machine guns to ward off enemy fighters. Equally impressed with the Boeing design was the local press who on account of having so much guns dubbed it "A flying Fortress" And with that legend was born. ... well not exactly... The aircraft was flown to Wright Field Ohio for military testing and an official handover when disaster struck. Back then to keep the elevators safe from wind damage when on the ground, blocks were slipped on the wings to keep them locked. During one of its evaluation flights, the ground crew had forgotten to take the locks off which made the plane stall and crash, killing its crew. Although there was no mechanical failure or pilot's error here, the crash led to the design not being able to finish evaluation flights and Douglas being rewarded the contract and its DB-1 design entering service as the B-18 Bolo. But that crash did lead to the first of many revolutions in aviation that the B-17 can attribute to itself. Because the Air Corps introduced mandatory checklists that ground crew had to follow to the letter so that further crashes and loss of life could be avoided. Pre-flight check lists are still in use today. Still, that's too bad, Boeing had a winner on its hands but were handed a knock out blow. But not nearly five months later Boeing got a surprise order for 13 model 299's modified with more powerful engines. Apparently the high command of the Air Corps had been so impressed with what the Model 299 brought to the table that they wanted more. F-1 funding was supplied to Boeing to have the planes made to the specified requirements and with the designation B-17, the 299 went into production. To be continued.