Wright Brothers day commemorates the anniversary Of December 17 1903 when The Wright Brothers – Orville and Wilbur, made the first controlled, powered and sustained heavier-than-air human flight in the Wright Flyer at Kitty Hawk in North Carolina. The Wright Brothers spent a great deal of time observing birds in flight & noticed that birds soared into the wind and that the air flowing over the curved surface of their wings created lift. Birds change the shape of their wings to turn and manoeuvre. They used this technique to obtain roll control by warping, or changing the shape, of a portion of the wing and they designed their first aircraft: a small, biplane glider flown as a kite to test this theory. Wing warping is a method of arching the wingtips slightly to control the aircraft’s rolling motion and balance. Over the next three years, Wilbur and his brother Orville designed a series of gliders flown in both unmanned (as kites) and piloted flights. They read about the works of Cayley, and Langley, and the hang-gliding flights of Otto Lilienthal. They corresponded with Octave Chanute concerning some of their ideas. They recognized that control of the flying aircraft would be the most crucial and hardest problem to solve.
Following a successful glider test, the Wrights built and tested a full-size glider & selected Kitty Hawk, North Carolina as their test site because of its wind, sand, hilly terrain and remote location. They successfully tested their new 50-pound biplane glider with its 17-foot wingspan and wing-warping mechanism at Kitty Hawk, in both unmanned and piloted flights, which became the first piloted glider. Based upon the results, the Wright Brothers refined the controls and landing gear, and built a bigger glider. In 1901, at Kill Devil Hills, North Carolina, the Wright Brothers flew the largest glider ever flown, with a 22-foot wingspan, a weight of nearly 100 pounds and skids for landing. Unfortunately the wings did not have enough lifting power; forward elevator was not effective in controlling the pitch; and the wing-warping mechanism occasionally caused the airplane to spin out of control.
The Wright brothers Then built a wind tunnel to test a variety of wing shapes and their effect on lift And This helped them get a greater understanding of how an airfoil (wing) works and they could calculate with greater accuracy how well a particular wing design would fly. They planned to design a new glider with a 32-foot wingspan and a tail to help stabilize it. So during 1902, the brothers flew numerous test glides using their new glider. Their studies showed that a movable tail would help balance the craft and the Wright Brothers connected a movable tail to the wing-warping wires to coordinate turns. With successful glides to verify their wind tunnel tests, the inventors planned to build a powered aircraft. After months of studying how propellers work the Wright Brothers designed a motor and a new aircraft sturdy enough to accommodate the motor’s weight and vibrations. The craft weighed 700 pounds and came to be known as the Flyer. The brothers built a movable track to help launch the Flyer. This downhill track would help the aircraft gain enough airspeed to fly. After two attempts to fly this machine, one of which resulted in a minor crash, Orville Wright took the Flyer for a 12-second, sustained flight on December 17, 1903. This was the first successful, powered, piloted flight in history.
Pan American Aviation Day
Pan American Aviation Day is a United States Federal Observance Day observed December 17. According to 36 U.S.C. § 134, on Pan American Aviation Day the president calls on “all officials of the United States Government, the chief executive offices of the States, territories, and possessions of the United States, and all citizens to participate in the observance of Pan American Aviation Day to further, and stimulate interest in, aviation in the American countries as an important stimulus to the further development of more rapid communications and a cultural development between the countries of the Western Hemisphere.” The date commemorates the first successful flight of a mechanically propelled heavier-than-air craft, accomplished on December 17, 1903, by the Wright brothers near Kitty Hawk, North Carolina.
B-47 Stratojet bomber
The Boeing B-47 Stratojet long range, six-engine, turbojet-powered strategic bomber made its Maiden flight 17 December 1946. It was designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraft. The B-47’s primary mission was to drop nuclear bombs on the Soviet Union. The B-47 entered service with the United States Air Force’s Strategic Air Command (SAC) in 1951. It never saw combat as a bomber, but was a mainstay of SAC’s bomber strength during the late 1950s and early 1960s, and remained in use as a bomber until 1965. It was also adapted to a number of other missions, including photographic reconnaissance, electronic intelligence and weather reconnaissance. The B-47 arose from a requirement for a jet-powered reconnaissance bomber, drawn up by the U.S. Army Air Forces (USAAF). Boeing was among several companies who responded its initial design, the Model 424, was basically a scaled-down version of the piston-engined B-29 Superfortress equipped with four jet engines.
In 1944 this initial concept evolved into a new bomber with a maximum speed of 550 mph (890 km/h), a cruise speed of 450 mph (720 km/h), a range of 3,500 mi (5,600 km) and a service ceiling of 45,000 ft (13,700 m). Wind tunnel testing had shown that the drag from the engine installation of the Model 424 was too high, so Boeing’s entry was a revised design, the Model 432, with the four engines buried in the forward fuselage. The USAAF awarded contracts to four companies – North American and Convair concentrate on four-engined designs (to become B-45 and XB-46), while Boeing and Martin built six-engined aircraft (the B-47 and XB-48) powered by General Electric’s new TG-180 turbojet engine.
In May 1945, the von Kármán mission of the Army Air Forces inspected the secret German aeronautics laboratory near Braunschweig. The chief of the technical staff at Boeing, George S. Schairer had heard about the swept-wing theory of R. T. Jones at Langley, and after seeing models of swept-wing aircraft and extensive supersonic wind-tunnel data generated by the Germans, changed the design of the B-47 wing.Analysis work by Boeing engineer Vic Ganzer suggested an optimum sweepback angle of about 35 degrees. So Boeing’s aeronautical engineers modified their Model 432 to create the “Model 448”, which was presented to the USAAF in September 1945. The Model 448 retained its four TG-180 jet engines in its forward fuselage, with two more TG-180s in the rear fuselage. However the engines were moved out to streamlined pods (pylon mounted) under the wings, leading to the next iteration, the Model 450, which featured two TG-180s in a twin pod mounted on a pylon on each wing, plus another engine at each wingtip. Boeing’s team of engineers continued to refine it, with the outer engines being moved further inboard. In 1946 The USAAF ordered two prototypes, designated “XB-47”.
The first XB-47 was rolled out on 12 September 1947, and The XB-47 prototype flew its first flight on 17 December 1947 (the anniversary of the Wright Brothers’ first four flights on 17 December 1903), with the test pilots Robert Robbins and Scott Osler Flying from Boeing Field in Seattle to the Moses Lake Airfield in central Washington state.In 1949, Russ Schleeh and Joe Howell “broke all coast-to-coast speed records” flying from Moses Lake Air Force Base to Andrews Air Force Base averaging 607.8 miles per hour. During early tests of the XB-47 prototype, the canopy came off at high speed, killing pilot Scott Osler resulting in a canopy redesign. The second XB-47 (46-066) prototype flew on 21 July 1948 Serving as a flying test bed until retiring in 1954. This had more powerful General Electric J47-GE-3 turbojets with 5,200 lbf (23 kN) of static thrust each. Chuck Yeager also flew a test of the XB-47.
Both XB-47 prototypes were test flown at Edwards AFB, however the number one XB-47 (46-065) was disassembled and eventually scrapped by the Air Force in 1954, thus making the number two prototype (46-066) the sole surviving XB-47. Upon retirement, XB-47 (46-066) was restored and placed on display at the Octave Chanute Aerospace Museum in Rantoul, Illinois until it closed in 2015. Whereupon the Flight Test Historical Foundation began fundraising efforts to purchase XB-47 (46-066) for relocation to the Flight Test Museum at Edwards AFB. The purchase was completed in August 2016 and on September 21st, 2016 the aircraft arrived at Edwards AFB for reassembly, restoration and eventual and it is currently on display at the Flight Test Museum. In 1948 USAF decided to put the North American bomber into production on a limited basis as the B-45 Tornado. the Boeing XB-47 and the Martin XB-48, proved superior and A formal contract for 10 aircraft was signed on 3 September 1948. The USAF Strategic Air Command operated B-47 Stratojets (B-47s, EB-47s, RB-47s and YRB-47s) from 1951 through 1965. The B-47 had a three man crew – the aircraft commander, copilot, and a navigator/bombardier or a crew chief.
Unfortunately the B-47 initially had a few problems The aircraft was sluggish on takeoff and too fast on landings, a very unpleasant combination. If the pilot landed at the wrong angle, the B-47 would “porpoise”, bouncing fore-and-aft. If the pilot did not lift off for another go-around, instability would quickly cause the bomber to skid onto one wing and cartwheel. However by 1953 it was redesigned and performance was closer to that of jet fighters of the period and it was so fast and agile the aircraft set records with ease. Improved training led to a good safety record.The B-47’s reliability and serviceability were regarded as good although avionics reliability remained problematic throughout the B-47’s operational life.
From 1950, several models of the B-47 included a fuel tank inerting system in which carbon dioxide vapor was used while fuel pumps operated or during in flight refueling to reduce the amount of Oxygen and minimize the risk of an explosion caused by static electricity discharge. An XB-47 was flown in the 1951 Operation Greenhouse nuclear weapons testing. This was followed by a B-47B being flown in the 1954 Operation Ivy and the 1955 Operation Castle. A B-47E was then flown in the 1956 Operation Redwing. Three B-47s flew cross country from March Air Force Base to the Philadelphia International Airport as participants in the 1955 Labor Day race. In the 1956 event, three B-47s participated in the G.E. Trophy race for Jet Bombers, flying from Kindley Field, Bermuda, to Oklahoma City. One of these set a course speed record of 601.187 MPH. By 1956, the U.S. Air Force had 28 wings of B-47 bombers and five wings of RB-47 reconnaissance aircraft. The bombers were the first line of America’s strategic nuclear deterrent, often operating from forward bases in the UK, Morocco, Spain, Alaska, Greenland and Guam. B-47s were often set up on “one-third” alert, with a third of the operational aircraft available sitting on hardstands or an alert ramp adjacent to the runway, loaded with fuel and nuclear weapons, crews on standby, ready to attack the USSR at short notice. Crews were also trained to perform “Minimum Interval Take Offs (MITO)”, with one bomber following the other into the air at intervals of as little as 15 seconds, to launch all bombers as fast as possible. In 1959 the B-52 began to assume nuclear alert duties and the number of B-47 bomber wings was reduced. B-47 production ceased in 1957, though modifications and rebuilds continued after that.