Boeing 787's Quiet Technology is put to the Test.

A Boeing 787 performs a low fly-over in Glasgow, Montana, during a test of the airplane's community noise level. Engineers spent years trying to reduce the noise profile of the 787, which is designed to be much quieter than today's similarly-sized airplanes.

Several years ago, in an office building near the 787 Dreamliner factory, a small group of Boeing engineers were quietly working on a lofty goal.

"We were trying to make the 787 airplane come out the quietest airplane of its size and capability," recalls noise engineer Mark Sandstrom.

Sandstrom and his colleagues set out to look for ways to make the jetliner quieter from tip to tail, participating in every facet of the Dreamliner's design.

In the video above, you can hear the results as two 787 test airplanes were brought to Glasgow, Montana for tests of its community noise levels.

First, flight test engineers embedded ultra-sensitive microphones along the runway of a secluded airfield. Then, Boeing test pilots performed multiple takeoffs and approaches, testing each engine thrust setting to see how much noise the airplane generated.

The 787's noise footprint will be as much as 60% smaller than today's comparable airplanes.

"For the approaches, you'll come in, you'll pitch the airplane over," says Boeing test pilot Captain Craig Bomben. "You have to pitch over at a certain location and then the pilot's responsibility is to hold air speed as constantly as possible. Any deviations in air speed up to say 5 knots, 4 to 5 knots, could affect the signature of the airplane as it goes through the air.

For many of the test conditions, the 787 is so quiet as it approaches that you can hear birds chirping and cameras clicking until the airplane is right on top of the runway.

"We have to publish numbers to the one-tenth of a decibel, which is your human ear can't hear the difference," explains Sandstrom. "We have to define to that level of numerical precision."

Early data show the 787's noise footprint will be as much as 60% smaller than today's comparable airplanes, thanks to a host of design improvements. A new generation of engines with very high bypass-ratios Advanced acoustic linings New engine inlets and nozzles Lightweight composite materials New, more aerodynamic wing

Sandstrom says the 787's lightweight composite fuselage and more aerodynamic wing don't just help the airplane fly more efficiently, it also affects what people hear on the ground.

"If you climb higher on the same amount of energy and fuel, you've gotten further away from ears and microphones," says Sandstrom.

The results represent a big leap not only for Boeing but for the aviation industry.

"We have gone to great strides to try to reduce the noise signature of the airplanes to be better stewards of the environment, better stewards of the community," says Capt. Bomben.

"We can't expect to grow the number of airplanes higher and higher unless their environmental impact is minimized," says Sandstrom.

Category:

Science & Technology

Tags:

• boeing
• 787
• dreamliner
• 787-8
• runway
• sound
• quiet
• technology
• test
• take-off
• engines
• rolls
• royce

[buknoy7]

hi..im just curious... where did you get those videos? esp the 787-8 thing... Very nice. . . i love them. =) keep those videos coming!

[Altumkell]

@buknoy7 Hi! hope you like it .This video belongs to Boeing , Subscribe for more airplane videos!

[M0ntaroo]

pretty kool

[Altumkell]

@M0ntaroo yeah ! Cant wait to see the 787-9!

[JeanPaulTron]

Pretty awesome listening to how quiet this engine is HOLY SHIT LOUD AS FUCK PILOT INTERVIEW

[Moerdarvalen]

But will it blend?

[xXGeneral767Xx]

Great Video. I am Guessing Airbus disliked this video.

[crispiegee1]

Boeing: The finest passenger planes in the world.

[stargazer444]

to quite for me I'd rather hear a 707

[normanmj]

The word "steward" or "being good stewards" is way overused these days. Nice airplane though.

[voldemort2123]

@bridgecross they're swept...

[fillopygeesi]

Big jets sound awesome and there tying to take the sonnd away

[ItsCoreyLynxxYall]

@kbReXz I'm sure the armed forces will have their own variant for whatever use. They've already got some pretty advanced aircraft of their own though. This was made with civilian transport in mind. =)

[ItsCoreyLynxxYall]

Shhhh! Listen to the engines, as I talk over the sound. 

[dvddmc]

first plane due end of sept 2011

@lufthansa330pilot

[durganjali1]

wow...........superb its amazing,gud job humans