Technology being tested on this Boeing 777 in Montana is
expected to find its way into 787s, due to enter service in
2008, and the 747 Advanced. (August 11, 2005)
Credit: James Wallace/Seattle Post-Intelligencer
Posted on 08/13/2005 2:43:03 PM PDT by Paleo Conservative
GLASGOW, Mont. -- At a remote airfield in northeastern Montana, where the quiet is usually broken only by the singing of Western meadowlarks, a Boeing 777-300ER jetliner made some symbolic noise of its own Wednesday.
But it was the lack of noise from the big plane that will help advance aviation.
The Boeing Co. and some of its partners, including NASA, are testing new methods and technology that can make commercial jetliners quieter when landing and taking off -- a growing concern at airports from Sea-Tac to Singapore and Paris.
Passengers also will benefit from the ongoing efforts as cabin noise will be significantly reduced.
Some of the technology being tested here will find its way onto the 787, which is due to enter airline service in 2008, as well as the 747 Advanced and even planes now in production.
Technology being tested on this Boeing 777 in Montana is
expected to find its way into 787s, due to enter service in
2008, and the 747 Advanced. (August 11, 2005)
Credit: James Wallace/Seattle Post-Intelligencer
Wednesday, with reporters watching and listening from the ground, as well as representatives from NASA, General Electric and Goodrich, a 777-300ER on loan from All Nippon Airways made several low-level passes over the airfield to demonstrate advanced noise-reduction concepts.
More than 600 ground-based microphones, acting like acoustic cameras, monitored the jetliner's noise as it flew overhead, and computers wired to the microphones immediately analyzed the data and verified that the modifications made the big jet less noisy.
"We are trying to make the 787 significantly quieter" than today's planes, said Eric Nesbitt, a noise engineer in Boeing's product development for commercial airplanes.
He helped develop the Boeing test program, known as "quiet technology demonstrator."
What's taking place here in Glasgow is a follow-up to noise testing done here in 2001.
The twin-engine 777-300ER has the world's biggest and most powerful jet engines, the GE90- 115B. They are certified for 115,000 pounds of thrust. On the test plane, the left engine is the standard GE90-115B. But the right engine is modified to include acoustics that make nearly 100 percent of the nacelle inlet inner surface sound-absorbent. The nacelle is the casing that wraps around a jet engine.
The noise that comes out the front of a jet engine, produced by the fan as well as the low-pressure booster that sends air through the core, causes a buzz-saw type of noise that can be heard by passengers in the front of the passenger cabin, often in first and business class. The new acoustic inlet liner significantly reduces that cabin noise.
Some of this noise also hits the ground on takeoff or landing, so the nacelle treatment also helps with ground noise.
"We need this to be production-ready in time for the 787," Nesbitt said.
Within an hour of Wednesday's tests, Boeing had downloaded noise data from a life-size dummy seated in seat 7H in the front cabin of the 777. Microphones in the ears of the dummy heard exactly what a passenger would have heard in that seat. At the start of the Glasgow testing last week, Boeing ran baseline tests before the right production engine was modified.
The reduction in the buzz saw noise was significant.
Another noise-reduction development being tested on the 777 is a chevron, which is attached to the exhaust duct of the right engine, as well as to the secondary fan nozzle at the end of the nacelle on the same engine.
The sawtooth pattern of the chevron reduces engine noise -- that heard in the rear cabin as well as the "community noise" that is heard on the ground when a jet takes off. Chevrons will be used on the 787.
A couple different chevrons will be tested as part of QTD2, including a "smart" chevron. The metal alloy changes shape in flight, depending on temperature.
Environmental concerns such as jet engine emissions and airplane noise have become much more important to the industry in recent years, and are driving both engine makers and airplane manufacturers Boeing and Airbus to make their products more "green."
During tests at the Glasgow site with a 777 in 2001, Boeing found that two engines equipped with chevrons made no more noise than a single engine without the chevron.
The Boeing test facility is in the northeastern corner of Montana, about 25 miles north of Glasgow. The airfield was used to train B-17 pilots during World War II and in late 1944 a camp was built at the site to house German prisoners of war. In the 1960s, a Boeing B-52 strategic bomber wing was located there, at what by then was Glasgow Air Force Base. The base closed in the 1970s and much of the property, after sitting idle for years, was purchased by Boeing as an aircraft test facility.
Current testing started Aug. 2 and is set to end by Aug. 25.
The serrated chevron works by producing a better mix of the exhaust gas from the engine's core, the fan-driven bypass air flowing through the nacelle and the ambient air that passes around the nacelle. When these three air flows are properly mixed, engine noise is reduced.
A shock wave produced by the exhaust creates a loud noise that hits the rear fuselage, creating sound passengers can hear. The chevrons will reduce that noise.
On the 787, it will mean Boeing will not have to put as much sound-proofing material in the plane's sidewalls, helping reduce the 787's weight and improving its fuel burn.
The current QTD2 tests will pave the way for QTD3 in a few years. That will test noise reduction technology for the next new Boeing jet, a 737 replacement that could be flying by around 2012.
Boeing has not yet decided when it will launch development of its next plane after the 787, but has said timing will be driven by engine makers.
But efforts by Boeing and others to make airplanes more efficient and more quiet aren't likely to end here.
Said Walt Gillette, vice president of 787 development:
"It's a never-ending quest."
Or they ripped off the Batplane. :-)
Black planes won't cut it in PHX.
A good point. That would be an outstanding competitive advantage for them - the other guy's airplanes are prohibited from taking off while your airplanes are departing every thirty minutes!
Boeing to Demonstrate Quiet Jets Can Be Even Quieter
SEATTLE, Aug. 10, 2005 -- Demonstrating even lower-noise features on an already quiet 777-300ER is the goal of a three-week flight test program led by Boeing [NYSE: BA] and called the Quiet Technology Demonstrator "2" (QTD2).
Flight testing is under way at the company's Glasgow, Montana, test facility where several advanced noise-reduction concepts will be tested. These include chevrons on the engine exhaust ducts and new acoustic treatment for the engine inlet. Landing gear noise reduction features also will be tested to lower aircraft noise during landing.
The program is an equal cost-sharing project between The Boeing Company, the General Electric Company, Goodrich Corporation's Aerostructures division, and NASA. All Nippon Airways of Japan is providing one of its soon-to-be-delivered 777-300ER airplanes for the flight test activities.
Each company is validating key technologies for incorporation into its own current and future products. NASA is joining the industry effort to acquire data to test some of its advances in propulsion aeroacoustics and computational fluid dynamics.
QTD2 follows on the heels of an earlier program -- called the Quiet Technology Demonstrator -- with members of the international aerospace industry. That program verified significant noise reduction solutions, some of which are now standard on the 777.
"All Boeing hardware is built to flight-test standards," said Walt Gillette, vice president, 787 airplane development, Boeing Commercial Airplanes. "This means that once we have demonstrated the success of these technologies, we'll be in a position to rapidly implement them on specific products, such as the 787 and other Boeing airplanes.
"We are always looking to the future well beyond our next new airplane. Improving the performance of our airplanes -- making them quieter for communities, ground crews and those on board the airplane -- is an ongoing effort."
"All Boeing hardware is built to flight-test standards,"
Wow!
Back when they enforced Stage 3, the cut off date was December 21, 1999 for all stage 2 craft. It was what finally killed our last 737-100, the last one flying in America.
While it hurt to see such an old soldier turn into beer cans, I'm relieved, because I fully expected that beast to crash.
I kinda miss the noise every once in a while from the older jets, we have some KC135/707's at the AZNG that I think are exempt, noisy, sooty planes. Gotta love that.
As I recall this all got started with the proposed 747-400QLR program that was never launched. If the 747 Advanced is launched, this technology will will be incorporated into it. It would make no sense to continue building any previous 747 models, because the ability to operate at Heathrow or Gatwick at any time of day would affect the resale value of the aircraft.
Beer cans? Why wasn't it donated to the Smithsonian? There weren't very many of the 100 model built. I read on another online bulletin board that the orders for 737's is closing in on 6,000. The 5,000'th is to be delivered later this year.
Being near it on takeoff was like having a chainsaw going through the middle of your brain.
It was an experimental unducted fan engine. They were tested on both 727's and MD-80's back in the late 1980's. They were supposed to drastically cut fuel consumption, but they were very noisy.
Our plane, #708 was flown to Opa-Lacka, and torn apart. I flew on it many times, never felt safe.
I heard it was a weed whacker!
In the late 80's I worked in a hangar where they were doing a conversion to 727's, removing the center engine and putting 2 MD-80 engines in on the sides. It was a long process, they had a Danish plane from Sterling in for a long time.
It never really took off, the 727's were on the decline back then, now they are all gone but for cargo.
I don't know, but it looks like it could whip up one mean frozen margarita.
Last commercial plane flying.
The NASA one has been around forever, and I think the Army or Navy has a few.
You ever see the 720B that is at PHX?
Its a Honeywell testbed plane, they put engines on the side of the front fuselage and fly and test it. Its an old PA bird, we used to have to walk under it to get to the bus.
Rivet city!
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