The first US jet bomber business began in 1943, with three companies launching the concept in January 1944 and first flight in 1947. It started in the midst of World War II and came out two years later.
The concept of the early jet bomber was to replace the existing straight wing propeller type with the turbojet. In the case of Boeing, the size of the B-29 was reduced.
The companies involved in the project were North American, Conveyor, Boeing, and NACA, the forerunner of NASA, tested wind tunnel tests, all with similar results.
After the end of the war, Boeing's aerodynamic engineer, George Shirell, went to Germany as a technical investigator.
Martensa, who developed the B-26, also entered the jet bomber business in the middle, and a total of four companies began to compete.
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The design originally proposed by Boeing (called Model 424) had drag problems and was not addressed in the Model 432, an amendment that bogged down the engine. After that, I begin to seriously worry about introducing a recession.
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Boeing offered a Model 448, which was designed to bury the engine in the fuselage and introduce retreats, but the Air Force strongly refused. This is because the engine could be a direct hazard if it caused a fire.
Boeing decided to put the engine back on its wing, but again it faced drag problems. So I put a couple of engines into one shell and trim it with a smoother shape to some extent.
The US military was pleased with the revised design of Boeing, but there were many problems. The new bomber was designed to be a high-speed aircraft, so its wings were thin and could not be deployed. So, I designed a bicycle landing gear to place the gears in series on the fuselage and keep the left and right balances as small gears inside the engine pods.
This arrangement of landing gears made it very difficult to lift the nose when taking off, and Boeing solved it by keeping the nose on the ground when the plane was on the ground.
Boeing knew that extending the tip of the wing to increase the range of the bomber would have an effect, so the wings would be longer.
In 1946, the design of Boeing was made into a prototype named the XB-47 Stratodet, but many thought the plane was unrealistic and would only be experimental. The reason is because of its futuristic appearance.
On the other hand, Boeing officials who participated in the development were excited about the achievement of the aircraft history.
The first flight of Stratozeth was on December 17, 47, and it was perfect, except for the emergency flap that turned the flaps off.
Stratozz's high lifting device, called the Fowler flap, was a very efficient structure that simultaneously raised area and camber.
Because the Stratjets are as fast as the fighters, they will have 50 caliber guns without massive defense arsenal in production. This is later improved to 20 mm.
Stratoz Jet fueled 17,000 gallons of fuel, 3.4 times the B-29, so fuel balance was very important.
Since the early turbojet did not have good propulsion at low speeds, the takeoff rocket propulsion system was built into the stator jet. But this is dangerous because it is close to the fuel tank.
There was a separate slowing parachute for the approach to the runway in order to maintain the low speed while maximizing the output at landing. If you lower the engine power, it takes a lot of time to raise the engine, so you can not re-raise in an emergency.
Stratojets was unusually a bomber and a tandem cockpit, like a fighter. A navigator serving as a bomber was aboard at the end of the nose.
Stratogether had a phenomenon that the pitch-up rider was over-heard in certain situations, which was the main cause of wing tip stall. So Boeing installed a vortex generator at the tip of the wing to suppress air separation.
Test pilot Robbins first begged God to save him before riding the Stratotjets, but later he liked the plane as special.
In order to adjust the speed of the Stratjet, the P-80 was the pursuer, but it could not catch up with the bomber. This chase pilot was Chuck Yeager and his ego was quite bad because he ignored bombers and bomber pilots.
Thus, Stratovets was a bomber with great potential, but some conservative generals did not seriously consider the introduction. Boeing, however, invited a general, Wolf, to propose an XB-47, and then on September 3, 1948, the Air Force purchased a Stratjet.
The first introduced Stratozeth was the B-47A, mainly used for air force operations and test evaluations.
The XB-47 was produced at the Seattle plant in Boeing, but all Stratozets after the B-47A were assembled at a state-owned factory in Kansas. The reason was that Seattle was too vulnerable to the bombing of the Soviet Union.
After testing the B-47A, the Air Force began mass-producing the B-47B with feedback, and signed a production contract with Lockheed and Douglas to secure the fastest possible volume.
The bombs of the B-47B were smaller than the B-47A and XB-47, as the bombs became smaller and smaller.
The Air Force had installed a boom-type probe in the B-47B jockey that could quickly inject a lot of fuel in the air, so it erased the glass nose cone and replaced it with several windows instead.
From the B-47B, the ejection seats were removed and the crews were forced to escape directly to the main door. I thought the pilots were very uncomfortable about this. In fact, George Martin, the B-47 program director, also showed Robinson (test pilot) to the Air Force's request to remove attendance. The reason is that if you have a problem later, blame the Air Force.
The B-47E, an improved version of the B-47B, has significantly enhanced engine thrust and water injection. This water injection sprayed a mixture of water and methanol into the compressor to prevent overheating, allowing for even greater combustion. Instead, he poured a lot of black smoke and made a thundering sound.
As the thrust increased, the need for an auxiliary rocket for takeoff was reduced. I used it occasionally during emergency riding or training, so I switched it to an external one and was able to get rid of it.
The successor of the B-47B became the B-47E because the B-47C and the B-47D were specially designed for testing purposes and were not mass-produced.
A total of 1,341 B-47Es were produced.
The Stratjet was also retrofitted with the reconnaissance RB-47E.
Stratozzet said it was like driving a fighter because it reacted sensitively to moving the stick. Particularly, the distinctive water drop canopy has improved such a feeling.
The Stratjet canopy had good visibility, but on days when the weather was clear, it made the cockpit a hot box.
The B-47 used to be trained as a minimum interval takeoff, which was a tactic to take off as many bets as possible while keeping the bombers 15 seconds apart. However, the front bomber was quite dangerous when it sprayed turbulence and smoke to the rear bombers.
The B-47 had a lot of low-level bombing exercises. When flying at low altitudes near the target, the way to drop the nucleus while rushing. This caused a crash in the structure several times, and thus reinforces the wing coupling.
The B-47 reconnaissance RB-47 series frequently invaded the Soviet territory and suffered quite a lot. Instead, the families of crewmembers who died because all operations were confidential, did not know where their father, husband, or son died.
In fact, the RB-47, which invaded the Murmansk airspace, was attacked by the MiG-17 and returned to Finland by Finland, which Finland reported very seriously, but the US denied it.
With the development of the hydrogen bomb, the US Air Force has planned to unmannize the B-47B with a bomb. It's a huge cruise missile, but after review, it's not very practical, and it's canceled immediately.
The B-47 has been used or used for a wide variety of applications, including weather observers, tankers, and electronics. Even trying to retrofit it as a platform for Rascal, a supersonic site cruise missile.
The last flight of the B-47 is June 17, 1986.
