Weapons of World War Two
B-17G Flying Fortress
The 28th July 1935, in Seattle, Washington State, started its test flights a large four-engined aircraft built by Boeing as consequence of a request from the Army Aviation Corps, made little more than one year before. The aircraft had been obtained by reelaborating two previous projects: one of a four-engined transport and other of a bomber abandoned in the experimental stage, the XB 15. The results of the trials were deemed satisfactory, despite a disastrous accident that destroyed the prototype in October, and it was ordered a preseries of thirteen B-17, acronym with which the new aircraft was denominated.
In 1938 finally arrived the order for 36 series aircraft. From that moment began officially the life of this exceptional flying machine which would be of the first ones bringing the total war from the European to the Pacific skies. During the conflict were produced 12371 exemplars of the B-17, which operated at the same time in the two largest war theaters, either with American distinctives or the ones of the Royal Air Force, to which some more than 600 exemplars were granted.
But the war debut in the European skies was not one to be enthusiastic about. When the first massive incursions were started in German territory, the Americans, trusting the powerful armament and the heavy armor of their "Flying Fortresses", as the B-17 were denominated, used them for bombing missions without air escort. It was a very serious mistake that the crews paid at hard price. The fighters of the Luftwaffe inflicted so high losses to the B-17 that the American command had to revise its theories and protect better their aircraft.
Think that the 27th August 1943, in a single incursion over the bearing factories of Regensburg and Schweinfurt, the Americans lost 60 B-17 out of 376 (and with them 540 men of the crew), and the 14th October, always over the same target, 198 B-17 out of 291 (60 downed and 138 so damaged that they could not be repaired). The losses in the crew on this second mission were more than twice than in the previous one. On the other hand, the Luftwaffe, in the two actions, lost about 50 aircraft, even if the Allied propaganda boasted of having shot down 186 aircraft only in the second raid.
But let us see the structure of a B-17 of the series G, the most produced one, depicted in the illustration. It was a large four-engined aircraft of entirely metallic structure, of low wing, circular section, with a high and characteristic vertical tail plane. Its structure was specially light due to the wide utilization of special alloys that had been made, but it offered at the same time a foolproof robustness that allowed to whitstand notable damages without compromising the stability of the aircraft.
The aircraft was fitted with an electric system that fed the near totality of the services, an oleodynamic system used to regulate the refrigeration of the engines and for the brakes of the landing gear, and an effective centralized system for oxygen breathing at high altitudes for the entire crew. There was also a heating system. The notable operational range and the possibility of transporting a good load of bombs made the B-17 a terrible weapon. The crew, protected by the thick armor, had at their disposal thirteen 12.7-millimeter machine guns.
After the first losses were produced some YB 40, B-17 modified by increasing the armor and the armament. These should have acted as escort for normal bombers, but the formula was a failure. Fitted with the excellent sight Norden for precision bombing, the "Flying Fortresses" often saw the effect of this device nullified by the infamous tactic known as "carpet bombing". After the war, the B-17 were employed in the aviation of many small countries, while in their homeland they would be used as "water bombers" for fighting forest fires.
Wingspan: 31.63 meters
Wing area: 131.92 square meters
Length: 20.95 meters (XB-17); 22.67 meters (B-17G); 22.78 meters (XB 40)
Height: 4.57 meters (XB-17); 5.81 meters (B-17G and XB 40)
Full load/Empty weight: 19504/10027 kilograms (XB-17); 29710/16400 kilograms (B-17G); 28710/16736 kilograms (XB 40)
Payload/Crew: 9477 kilograms/8 (XB-17); 13310 kilograms/9 (B-17G); 11974 kilograms/9 (XB 40)
Engines: Four Pratt and Whitney R 169 OE of 760 horsepower (XB-17); four Wright R 1820 of 1217 horsepower or R 1897 of 1014 horsepower (B-17G and XB 40)
Time to reach 3048 meters of altitude: 13 minutes 18 seconds (XB 40)
Time to reach 6096 meters of altitude: 37 minutes (B-17G)
Cruising speed: 328 kilometers/hour (XB-17); 293 kilometers/hour (B-17G); 315 kilometers/hour (XB 40)
Maximum speed: 380 kilometers/hour (XB-17); 462 kilometers/hour (B-17G); 399 kilometers/hour (XB 40)
Service ceiling: 7504 meters (XB-17); 10851 meters (B-17G); 8900 meters (XB 40)
Defensive armament: Five 7.62-millimeter (later 12.7) machine guns (XB-17); thirteen 12.7-millimeter machine guns (B-17G); fourteen 12.7-millimeter machine guns (XB 40)
Drop armament: 1167 kilograms of bombs (XB-17); 2043-7893 kilograms of bombs (B-17G)
Operational range: 4834 kilometers (XB-17); 3219 kilometers with 2722 kilograms of bombs (B-17G); 3959 kilometers (XB 40)
Also in Weapons of World War Two: