787 Dreamliner completes wing-bending test
Flex test - the 787 was subjected to loads 150 percent greater than it can expect to endure during service (Photo: Boeing)
If you've ever felt a little queasy watching your plane's wings flex under the strain of being at 10,000 feet, rest assured that they can bend a lot further. Just how much pressure modern airliner wings can take is demonstrated by the latest 787 Dreamliner news from Boeing. During a recent "ultimate-load wing up-bending test," the 787 was subjected to loads 150 percent greater than it can expect to endure during service with the wings flexed upward by approximately 25 feet (7.6 meters) over a period of two hours.
Boeing is positive about the initial results of the test although more extensive analysis is required over coming weeks.
"We are looking forward to the technical team's report on the details of the test results," said Scott Fancher, vice president and general manager of the 787 program.
"The test program has been more robust than any conducted on a Boeing commercial jetliner," said Fancher. "It has taken countless hours of hard work by the Boeing team and our partners to work through the static test program."
About the Author
After a misspent youth at law school, Noel began to dabble in tech research, writing and things with wheels that go fast. This bus dropped him at the door of a freshly sprouted Gizmag.com in 2002. He has been Gizmag's Editor-in-Chief since 2007.
All articles by Noel McKeegan
I\'d like to see them let the wings go and watch them snap back...
Or to do the same test downwards....
Even better - to run one wing UP and the other wing DOWN - at the same time..
And then let them snap back.... Wooooooo it\'s explodes just like a balsa one!
This sort of testing is why Boeing planes don\'t shed pieces like an Airbus (see the October 2001 Airbus crash in New york) when the pilots get frisky with the controls. ;)
Boeing has long designed their planes to withstand anything a pilot can do, short of deliberately crashing.
Google for Boeing barrel roll. Test pilot Tex Johnston flew a prototype 707 through a barrel roll, just to prove it could do it. I\'d like to see Airbus try that with any of their airliners!
bet they didnt come back to where they started from! Next they\'ll be producing a cruise liner that flaps its wings like a bird! Now that would be funny!
One wing up and the other down? The cabin would not stay static in real life. That would be called a barrel roll! (which has it\'s own stresses!) We all know that real life wing flexing is not static but that is one of the tests they have to do. 25ft IS a incredible amount though! I wonder if it develops \"stretch marks\" like any human whose skin is called on to accommodate a lot of swelling in a short amount of time!
Will, the tink
I am a member of EAA, and saw the First Composite Airplane Fly, at Oshkosh back in 1973 The KR-1, and later the KR-2, which crashed with Ken Rand in it. The 787 will be flying at 50 to 55 thousand feet most of the time, where the air temperature is at least 80 below, plus high amounts of ultraviolet rays.which deteriorate the skin of the wings. When things are cold they shrink. Now when you land at Miami and the temperature is 95 degrees, wings expand. What happens to composite material as it gets older it gets BRITTLE, and breaks apart.
The Federal department of Transportation was testing Composite Pilings for over passes and they FAILED! And they weren\'t at 50,000 feet! Now you figure it out!
Being a retired Safety Director, to me Boeing is \"ROLLING DICE\"
There must be 15 articles where Composite pilings have failed the test. Here is one with pictures. http://www.tfhrc.gov/structur/pubs/04043/05.htm
I remember when the British Comets went apart in Midair, due to structure failure, due to the shape of the windows, they exploded in mid Air, 5 of them, till they found out the cause. The Comet was the first Jet Air liner.
jdlaughead, I don\'t think 5 Comets exploded in mid air. One exploded near India, and the other was near Italy, if my memory serves me correctly. The failure was put down to the squarish shape of the windows along the fuselage. Fatigue cracks appeared in the corners of presumably one window, which would have been enough to cause de-pressurisation at 30,000ft. However most windows are now this same shape, and of course the pilots cabin windows are always square, and don\'t seem to ever have failed. The Comet was the first jet passenger liner to have a pressurised cabin, so this was new territory at the time.
The Boeing test took place over a period of time, but wings are going to flex rather rapidly in flight, hopefully not by the tested amount!
It´s not as simple as you say.
It´s true that ultraviolet deteriorate some composite resins (not all), so it is not a major issue (you several layers of surface protection and paint before u get to CRFP).
Composites don´t expand and shrink (as much as metals do) due to temperature differences.
Fatigue behavior is far superior to Aluminum, as well corrosion resistance is better reasons why composites where chosen for 787.
The 787 is a move in the right direction and you can be sure it will be safe.
To certify such an new Airliner is not something that is taken lightly.
They would be utterly stupid not to test them.
the really interesting thing about the wings is how MUCH they flex compared to aluminum, on the ground they will almost droop, and during the take off roll as airspeed increases they will lift quite a bit at the tip until they hit cruise speed. The Boeing engineers designed a \"twist\" into the wings on purpose so that at approach speeds the wing will have a higher lift and in cruise it will have a lower drag. the big set back they had right before the first flight was caused by damage at the wing to body interface due to how much the wing will flex and what happens inside the wing at that junction.
I can\'t wait to see one up close!
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