The RAF Museum is open daily from 10am to 6pm with admission being free. Carparking is available but there is a charge. The nearest underground station is Colindale about a 10-15 minute walk away or a number 303 bus passes both the tube station and museum.
The plaque, attached to the sculpture, is inscribed:
"Sky Dance"
Aerobatics, air flow, vapour trails,
dynamics, structure and stresses
A sculpture for
the Royal Air Force Museum
to celebrate
100 years of powered, controlled flight
Conceived by sculptor
Kisa Kawakami
Realised by
Feilden Clegg Bradley - Architects
Buro Happold - Engineers
SH Structures - Fabricators
17th December 2003
Wikipedia in an article entitled "History of Aviation" tells us about the Wright Brothers first powered flights:
Using a methodological approach and concentrating on the controllability of the aircraft, the brothers built and tested a series of kite and glider designs from 1900 to 1902 before attempting to build a powered design. The gliders worked, but not as well as the Wrights had expected based on the experiments and writings of their 19th-century predecessors. Their first glider, launched in 1900, had only about half the lift they anticipated. Their second glider, built the following year, performed even more poorly. Rather than giving up, the Wrights constructed their own wind tunnel and created a number of sophisticated devices to measure lift and drag on the 200 wing designs they tested. As a result, the Wrights corrected earlier mistakes in calculations regarding drag and lift. Their testing and calculating produced a third glider with a higher aspect ratio and true three-axis control. They flew it successfully hundreds of times in 1902, and it performed far better than the previous models. By using a rigorous system of experimentation, involving wind-tunnel testing of airfoils and flight testing of full-size prototypes, the Wrights not only built a working aircraft, the Wright Flyer, but also helped advance the science of aeronautical engineering.
The Wrights appear to be the first to make serious studied attempts to simultaneously solve the power and control problems. Both problems proved difficult, but they never lost interest. They solved the control problem by inventing wing warping for roll control, combined with simultaneous yaw control with a steerable rear rudder. Almost as an afterthought, they designed and built a low-powered internal combustion engine. They also designed and carved wooden propellers that were more efficient than any before, enabling them to gain adequate performance from their low engine power. Although wing-warping as a means of lateral control was used only briefly during the early history of aviation, the principle of combining lateral control in combination with a rudder was a key advance in aircraft control. While many aviation pioneers appeared to leave safety largely to chance, the Wrights' design was greatly influenced by the need to teach themselves to fly without unreasonable risk to life and limb, by surviving crashes. This emphasis, as well as low engine power, was the reason for low flying speed and for taking off in a head wind. Performance, rather than safety, was the reason for the rear-heavy design, because the canard could not be highly loaded; anhedral wings were less affected by crosswinds and were consistent with the low yaw stability.
According to the Smithsonian Institution and Fédération Aéronautique Internationale (FAI), the Wrights made the first sustained, controlled, powered heavier-than-air manned flight at Kill Devil Hills, North Carolina, four miles (8 km) south of Kitty Hawk, North Carolina on December 17, 1903.
The first flight by Orville Wright, of 120 feet (37 m) in 12 seconds, was recorded in a famous photograph. In the fourth flight of the same day, Wilbur Wright flew 852 feet (260 m) in 59 seconds. The flights were witnessed by three coastal lifesaving crewmen, a local businessman, and a boy from the village, making these the first public flights and the first well-documented ones.
Orville described the final flight of the day: "The first few hundred feet were up and down, as before, but by the time three hundred feet had been covered, the machine was under much better control. The course for the next four or five hundred feet had but little undulation. However, when out about eight hundred feet the machine began pitching again, and, in one of its darts downward, struck the ground. The distance over the ground was measured to be 852 feet (260 m); the time of the flight was 59 seconds. The frame supporting the front rudder was badly broken, but the main part of the machine was not injured at all. We estimated that the machine could be put in condition for flight again in about a day or two." They flew only about ten feet above the ground as a safety precaution, so they had little room to maneuver, and all four flights in the gusty winds ended in a bumpy and unintended "landing". Modern analysis by Professor Fred E. C. Culick and Henry R. Rex (1985) has demonstrated that the 1903 Wright Flyer was so unstable as to be almost unmanageable by anyone but the Wrights, who had trained themselves in the 1902 glider.
The Wrights continued flying at Huffman Prairie near Dayton, Ohio in 1904–05. In May 1904 they introduced the Flyer II, a heavier and improved version of the original Flyer. On June 23, 1905 they first flew a third machine, the Flyer III. After a severe crash on 14 July 1905, they rebuilt the Flyer III and made important design changes. They almost doubled the size of the elevator and rudder and moved them about twice the distance from the wings. They added two fixed vertical vanes (called "blinkers") between the elevators, and gave the wings a very slight dihedral. They disconnected the rudder from the wing-warping control, and as in all future aircraft, placed it on a separate control handle. When flights resumed the results were immediate. The serious pitch instability that hampered Flyers I and II was significantly reduced, so repeated minor crashes were eliminated. Flights with the redesigned Flyer III started lasting over 10 minutes, then 20, then 30. Flyer III became the first practical aircraft (though without wheels and needing a launching device), flying consistently under full control and bringing its pilot back to the starting point safely and landing without damage. On 5 October 1905, Wilbur flew 24 miles (39 km) in 39 minutes 23 seconds."
According to the April 1907 issue of the Scientific American magazine, the Wright brothers seemed to have the most advanced knowledge of heavier-than-air navigation at the time. However, the same magazine issue also claimed that no public flight had been made in the United States before its April 1907 issue. Hence, they devised the Scientific American Aeronautic Trophy in order to encourage the development of a heavier-than-air flying machine.
The New Steel Construction website tells us about the sculpture:
The Royal Air Force Museum at Hendon, North London, has just built a new museum to house and display its large collection of military aircraft. The building, a giant silver tunnel-shaped hangar, has a striking 25 metre tall steel entrance canopy, designed by the Japanese sculptor, Kisa Kawakami.
The canopy touches the ground to provide benches for passers by, then rises to provide shelter at the entrance to the building. Sculptor Kisa Kawakami worked with structural engineers Buro Happold and architects Fielden Clegg Bradley to transform his original 25cm high paper model into reality.
The sculpture is one of the biggest pieces of permanent artwork in Britain, consisting of 20 tonnes of plate steel ribbons supported by a central cantilever post. Kisa quickly realised when making his model that a central post would be required to support the ribbons. Buro Happold has designed this post to be significantly stiffer than the ribbons, attracting the majority of the wind load and allowing the individual ribbons to be light. The use of a cylindrical section means that any torsion arising from wind loads can be carried directly down to the ground, where 48 mm diameter bolts take loads to the piled foundation. A goalpost frame at the entrance to the building gives additional lateral stability.
The five ribbons, each nearly a metre wide, are made of 12mm thick plate with three web stiffeners forming an “E” shape to give them strength whilst maintaining a lightweight, open section. Each stiffener was cut to the specific curve of the ribbon, providing a profile onto which the curved backing plate could be welded. Sliding joints at key locations prevent the ribbons from acting as props to the cantilever, which would result in them buckling under high winds.
Low frequency vibrations, caused by vortex shedding from the central post, could potentially have been a problem for this structure, and a dynamic analysis was carried out to check these effects. In fact, the windspeed for vortex shedding that coincides with the natural frequency of the sculpture was found to be very low. The deflections induced at this windspeed are insignificant, and hence no mitigation measures were required.
SH Structures Ltd was the steelwork contractor for the building, and it fabricated the entire sculpture off-site at its factory in Yorkshire. The sculpture was erected there to check for any imperfections, and then transported to London in sections and reassembled on the concrete pad foundations. There was little room for tolerance, with 18 bolts already cast into the pilecap at the main support, and no over-sizing of holes. The use of a casting template sheet, produced by SHS to the exact dimensions of the main baseplate, meant that bolts had been perfectly positioned and the main cantilever could be lifted directly into place. The joints between sections were then site welded and ground flush to achieve the same smooth finish as for the rest of the sculpture.
The distinctive yellow and grey colours of the sculpture can be seen from the motorway that passes behind the museum. This high profile entrance should attract more visitors to the astounding display of aircraft hung from the roof of the new building, an engineering feat worth an article in itself.