HKA From Canada, joined Jan 2006, 122 posts, RR: 0 Posted (3 months 3 days 8 hours ago) and read 3336 times:
My flying experience shows that:
A319/320 is more quiet compared to 737
A330 is more quiet compared to 767
A340 is more quiet compared to 777
My question is why and why can't Boeing make their planes quieter like Aribus. I believe cabin noise is annoying and is the main reason for jet lag IMHO.
PITIngres From United States, joined Dec 2007, 194 posts, RR: 2 Reply 1, posted (3 months 3 days 7 hours ago) and read 3312 times:
Unless you carried a decibel meter on, and sat in identically placed seats, your experience is unfortunately just anecdotal. I personally find 737's just as quiet (or noisy) as A320's. Is there any hard evidence for a cabin noise difference among the twins? (I can believe the A340 being quieter than the 777 due to half the engine noise generation being substantially farther from the cabin.)
CURLYHEADBOY From Italy, joined Feb 2005, 808 posts, RR: 1 Reply 2, posted (3 months 3 days 4 hours ago) and read 3260 times:
Quoting PITIngres (Reply 1): Unless you carried a decibel meter on, and sat in identically placed seats, your experience is unfortunately just anecdotal. I personally find 737's just as quiet (or noisy) as A320's. Is there any hard evidence for a cabin noise difference among the twins? (I can believe the A340 being quieter than the 777 due to half the engine noise generation being substantially farther from the cabin.)
I'm not an aviation professional but... yeah, sitting in the first row of a DC-9 was quiter than sitting mid-plane on a brand-new A340
If God had wanted men to fly he would have given them more money...
RoseFlyer From United States, joined Feb 2004, 5282 posts, RR: 17 Reply 3, posted (3 months 2 days 19 hours ago) and read 2981 times:
To add some actual credibility to this wandering conversation, yes there are some different levels of noise between the two manufacturers. Airbus is very correct that in certain conditions, the A330 and A340 are noticeably quieter than a 777. The cabin air circulation system is much quieter on Airbus widebodies than it is on Boeing widebodies. Airbus used a latest generation Hamilton Sundstrand product in those planes, which reduces cabin noise due to air circulation through the pressurization system. Air circulation is actually one of the largest noise sources inside a plane behind external wind noise and engine noise. Lower cabin air noise does not translate to a significant noise reduction over the course of the entire flight. It is noticeable when the engines are at a low thrust and the airspeed is low. So while on the ground or on approach, Airbus widebodies are quieter than a 767 or a 777.
On a completely different note, Boeing is using Hamilton Sundstrand on the 787 to make some key cabin air components which should help it reduce noise.
Due to the external air noise alone, at speed and altitude a DC9 is louder than a A340 even though the DC9 seems virtually silent at takeoff. In the end though, it is all about perception and not reality.
I design airplane parts for a living and am that guy that mechanics hate and blame for everything... the Design Engineer
Must less installed thrust, plus engines farther from the cabin.
Quoting HKA (Thread starter): My question is why and why can't Boeing make their planes quieter like Aribus.
I think they could, but it's a trade between weight, performance, and noise. The two OEM's just appear to have picked different balance points.
Quoting HKA (Thread starter): I believe cabin noise is annoying and is the main reason for jet lag IMHO.
It's definitely annoying, but there are quite a few studies that show that the major contributors to jet lag are cabin altitude, humidity, and circadian rhythm.
CRJ900 From Norway, joined Jun 2004, 1535 posts, RR: 2 Reply 5, posted (3 months 2 days 9 hours ago) and read 2813 times:
Doesn't engine type have a lot to do in this?
B767s use older, smaller engines like the CF6, while most A330s use the Trent 700 which has higher bypass ratio and is quieter. The B777 use GE90 which is friggin huge and makes noise while offering superior thrust.
EGNR From United Kingdom, joined Feb 2004, 429 posts, RR: 1 Reply 6, posted (3 months 1 day 5 hours ago) and read 2446 times:
Where you sit in the cabin has a huge effect on the perceived noise levels. In my experience the very front end (row 2) of an SK MD81/82 has been the quietest, even beating the front end of an SK A343 (I found rows 3 and 8 on the A343 quieter than row 1 - perhaps due to aerodynamics?), and upstairs on a BA B744 (in that order). Sitting between the GE90s of a BA B772 was a fraction quieter than sitting beneath the wing of a BAe 146-300. Sitting in the emergency exit row of a BAA319 (IAE V2500) was considerably quieter than the emergency exit row of a FR B738.
At the opposite end of the scale, the J41 makes an apalling noise (not necessarily overly loud, but the tone/pitch of the noise just gets to me) and vibrates like hell, and sitting down the back end of a BAC 1-11 can almost melt your brain.
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Luv2cattlecall From United States, joined Sep 2007, 1082 posts, RR: 0 Reply 9, posted (3 months 11 hours ago) and read 2191 times:
Quoting Tdscanuck (Reply 8): It's definitely annoying, but there are quite a few studies that show that the major contributors to jet lag are cabin altitude, humidity, and circadian rhythm.
Tom.
While I don't disagree with what you stated, I will say that buying some noise-canceling headphones does wonders for eliminating jetlag on long-hauls - not much difference for a transcon, but for anything east or west over 6 or so hours...world of difference!
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Je89_w From Singapore, joined Mar 2002, 1948 posts, RR: 8 Reply 10, posted (3 months 11 hours ago) and read 2189 times:
It all depends on where you are seated relative to the engine. On an AQ B732, sitting just behind the engine during takeoff sounded like I was in an F-15, although seated in front of the wing was quiet. As the engine's exhaust exits behind the wing, all you generally hear is a rumble if you're behind it.
Now videos of the A380's noise (or lack of) from the cabin was quite impressive!
TimePilot From Japan, joined Sep 2005, 253 posts, RR: 0 Reply 11, posted (2 months 4 weeks 1 day 20 hours ago) and read 2000 times:
In April I flew on a A340 and I found it to be quieter than a 747. Maybe it was my seat position, but especially on take-off I thought it was smoother and quieter.
I flew in row #1 on a 767 once and thought it was real quiet. Where's the fun though, if you can't hear the engines?
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CURLYHEADBOY From Italy, joined Feb 2005, 808 posts, RR: 1 Reply 13, posted (2 months 4 weeks 1 day 6 hours ago) and read 1864 times:
Quoting Je89_w (Reply 17): Now videos of the A380's noise (or lack of) from the cabin was quite impressive!
This statement of yours made a question pop in my mind...: Of course new aircrafts are generally quieter both from the inside and the outside, due to better noise reduction technology and quieter engines, but I was wondering if engines become louder as they age and if an aircraft turns quieter after being re-engined. Not talking of installing a new engine type, just the same engine but brand-new.
Anyone knows or have some figures?
If God had wanted men to fly he would have given them more money...
Tdscanuck From Canada, joined Jan 2006, 3822 posts, RR: 28 Reply 14, posted (2 months 4 weeks 1 day 3 hours ago) and read 1814 times:
Quoting CURLYHEADBOY (Reply 13): I was wondering if engines become louder as they age and if an aircraft turns quieter after being re-engined. Not talking of installing a new engine type, just the same engine but brand-new.
Anyone knows or have some figures?
Based on pure energy arguments, this is probably true. As engines age they get less efficient at extracting mechanical energy from the gas path, so more energy is going out the exhaust, so there should be some noise effect. However, I suspect it's so small compared to the overall engine noise level that it's not noticeable.
9VSIO From United Kingdom, joined Dec 2006, 334 posts, RR: 1 Reply 15, posted (2 months 4 weeks 1 day 2 hours ago) and read 1804 times:
Quoting Je89_w (Reply 10):
Now videos of the A380's noise (or lack of) from the cabin was quite impressive!
Having experienced it first hand, it truly is a VERY quiet aircraft! I could barely hear the engines spooling up to t/o power! All that noise insulation worked after all
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HKA From Canada, joined Jan 2006, 122 posts, RR: 0 Reply 16, posted (2 months 4 weeks 11 hours ago) and read 1687 times:
Thanks everybody for the comments.
In Summary, the contributing factors are:
1. Where you sit. This means pilots are really in the quietest location ! Maybe that is why they don't get as tired as the passengers.
2. Newer aircraft because of better technology are quieter
3. 4 engine aircarft (A340) cabin noise will less because of distribution of enginer noise etc
WILCO737 From Germany, joined Jun 2004, 4220 posts, RR: 68 Reply 17, posted (2 months 4 weeks 11 hours ago) and read 1680 times:
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Quoting HKA (Reply 16): 1. Where you sit. This means pilots are really in the quietest location ! Maybe that is why they don't get as tired as the passengers.
maybe we don't hear the engines so much, but you can't imagine how loud the wind around the nose and windows is in the cockpit. I always use my earplugs there. It is pretty loud in the front, louder than in the cabin.
WILCO737 (MD11F)
[Edited 2008-09-07 00:07:27]
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BuckFifty From Canada, joined Oct 2001, 1257 posts, RR: 18 Reply 18, posted (2 months 4 weeks 6 hours ago) and read 1611 times:
Quoting WILCO737 (Reply 17): maybe we don't hear the engines so much, but you can't imagine how loud the wind around the nose and windows is in the cockpit. I always use my earplugs there. It is pretty loud in the front, louder than in the cabin.
Actually, on the Airbus, we have quite a quiet cockpit. Guys coming from Jumbos and 11's are quite surprised by that. No need for earplugs at all.
WILCO737 From Germany, joined Jun 2004, 4220 posts, RR: 68 Reply 19, posted (2 months 4 weeks 6 hours ago) and read 1609 times:
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Quoting BuckFifty (Reply 18):
Actually, on the Airbus, we have quite a quiet cockpit. Guys coming from Jumbos and 11's are quite surprised by that. No need for earplugs at all.
Yep, that's true, but therefor the Airbus cockpit is incredibly loud on the ground with all these cooling fans
WILCO737 (MD11F)
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