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."
So why did Boeing not develop a twin engined 2 man cockpit version of the 727? I've always liked the 727 better than the 737. It seems that Boeing converted the 737 300-500 into the replacements for the 727. With the much bigger and heavier wing of the next generation 737, there really isn't a suitable Boeing replacement for the 737-500.
Probably too much work, you'd have to rewire the whole damn cockpit, replace everything.
Boeing did come out with a few 767's with a 3 manned cockpit. I think they went to Air New Zealand, they were modded I believe.
Shouldn't that engine have a few more decals? Pennzoil, Champion, Holley, and maybe a Budweiser or Winston.
Its still there, doesn't fly much, but when it does, its a sight!
Its N. of the Northernmost runway about halfway down.
I nonreved to SAN yesterday, never get used to that approach, hate that parking garage.
That plane was used for lots of important research programs. It was used to test concepts for glass cockpit instrumentation that eventually was put in the 757 and 767. It tested a GPS based navigational system for automated landings, and it was used to test the use of cockpits that have no direct view of the outside to evaluate their use in future SST's. They actually built a second cockpit inside what would be the passenger section of the plane, and it only had video images of the outside.
Now defunct Ansett Australia ended up with most of them.
And where is Air New Zealand now? Weren't the unions responsible for that purchase?
I didn't think there wer any of those left. I thought all the remaining ones were bought by the USAF to upgrade KC-135A's to KC-135E's.
You are right, I was in the right area of the world. I flew on Ansett a few times, great airline, I loved them. I did SYD-HKG, didn't fully grasp how long of a flight it really was!
They used to own a bit of AWA.
But then the plane wouldn't be able to leave the ground and would try to go around in counter-clockwise circles around the runways and taxiways.
Should Boeing just give the huge Chinese market to Airbus?
Well,,,,, I was told there was a pretty girl behind every tree in Glasgow, Montana. Problem was, there were no trees.........
Glasgow isn't very big now either with about 2000 or so.
When I left the base there were about fifty military people still on duty.
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